Wednesday, December 19, 2007

Colder this weekend, then mild again next week

We've been enjoying some nice milder than normal temperatures the past couple of days, along with the messy roads that go with it (the downside of milder temperatures in a Winnipeg winter) It looks like we'll get into some colder air this weekend (maybe enough to keep the car clean for a couple of days!) before milder temperatures return for next week, and the Christmas holiday. All in all, no major snowstorms to worry about over southern MB through Christmas at this point, although Saturday could be blustery with occasional snow. Have a safe and happy holiday wherever your travel plans take you!

Wednesday, December 12, 2007

Clipper may cause travel problems Thursday morning

An Alberta clipper system will be tracking across southern MB overnight into Thursday morning, bringing some snow and gusty winds behind it.  The combination of fresh snow and increasing north winds will create reduced visibilities in blowing snow mainly over the Red River valley on Thursday, especially in open areas outside of Winnipeg where near-blizzard conditions may be possible for a few hours Thursday morning.  Snow is expected to move into Winnipeg this evening with about 5 cm possible by Thursday morning. As the snow tapers off, winds will pick up from the north behind this system with gusts to 60 or 70 km/h Thursday morning giving blowing and drifting snow along with falling temperatures. As a result, be prepared for poor travelling conditions Thursday morning and allow extra time for the commute into work or school. Conditions should be improving by Thursday afternoon as a ridge of high pressure builds into western MB.

Monday, December 10, 2007

The week ahead

Dry and cold weather will dominate the weather picture today and Tuesday with highs in the minus teens both days. On Wednesday, an Alberta clipper will track into southern MB bringing milder temperatures into Southern MB, with highs of minus 7 predicted for Winnipeg by afternoon. If so, this would be the "mildest" day in Winnipeg since Nov 25th (over two weeks ago) when we hit -4C.  This clipper will also bring an area of snow with it, likely spreading into Winnipeg from the northwest by evening.  As the clipper passes into NW Ontario Wednesday night, snow will move through Winnipeg with up to 5 cm possible by Thursday morning along with gusty northerly winds developing. As a result, be prepared for a possible slow commute into work or school Thursday morning. Colder and drier conditions are expected for Thursday and Friday with highs on Friday only around minus 18. Long range models are hinting at a trend towards normal or even above normal temperatures next week.. but we'll have to see if those models continue with that trend over the next few days. Until then.. stay warm!

Monday, December 03, 2007

More snow on the way Tuesday..

The snow keeps coming..

After this weekend's brush with a Colorado low to our south, Southern MB will get more snow from an Alberta clipper system moving in from the west overnight into Tuesday. Some light snow is falling across southern MB today, but the main action is expected over Southern SK tonight moving into southern MB overnight into Tuesday as the clipper system becomes better organized. Current projections call for the bulk of the snow (10-15 cm) to fall across SW Manitoba south of a line from Swan River to Emerson continuing south into North Dakota (including Grand Forks and Fargo again). Winter storm watches are in effect for these areas, which will likely be upgraded to snowfall warnings later today. Winnipeg and Southeast MB should be on the eastern fringe of this system, but we could see about 5 cm of snow beginning early Tuesday.. which is all you need to make for poor travelling conditions.

Winter appears to be making up for its slow start in a hurry this year!

Saturday, December 01, 2007

Winter Storm Update

Snow has crossed the border into Southern MB this morning with visibilities down to 1 km in snow at the border in Emerson as of 9 am. Snow is falling across North Dakota and Minnesota this morning with visibilities down to 1 mile or less in Grand Forks and Fargo. Look for snow to get heavier in these areas through this afternoon with accumulations of 10 to 20 cm by tonight. Check out webcams over North Dakota and Minnesota to monitor the progress of this storm.

Here in Southern MB, the snow has pushed as far north as Morris as of 9:30 am and should continue to spread north into Winnipeg by midday or early afternoon. It looks like Winnipeg should stay on the northern fringe of this system with perhaps 2 to 4 cm of snow this afternoon through tonight. Higher amounts of 5 to 10 cm are possible south and east of the city including Morris, Steinbach, Emerson and Falcon Lake, with 10 cm or more over Northwestern Ontario. Expect deteriorating driving conditions this afternoon into tonight, especially south and east of Winnipeg. Improving conditions are expected Sunday as the storm departs the region overnight.

Thursday, November 29, 2007

Possible snowstorm south of the border this weekend

If you're planning on heading into the US for some cross border shopping this weekend.. be prepared for the potential of a snowstorm spreading into North Dakota and northern Minnesota Saturday into Saturday night. A Colorado low storm system is forecast to move across the central Plains into the Great Lakes this weekend, spreading an area of wintery precipitation over the northern Plains States. At this point, it appears the bulk of the snow will stay mainly south of the international border, but portions of southern MB especially along the US border will likely see some snow with this system. Places like Grand Forks, Fargo and northern/central Minnesota will likely bear the brunt of this storm with accumulations of 10 to 20 cm possible by Sunday morning. This is a developing storm system and it will bear watching, especially if you have travel plans into North Dakota or Minnesota this weekend.

Tuesday, November 27, 2007

Snow spreading into Winnipeg this evening

Snow will be overspreading Winnipeg quickly this evening as a weather system approaches from the west. Radar at 7:30 pm shows the leading edge of the snow approaching southwest Winnipeg, moving to the northeast, which should spread across all of Winnipeg between 8 and 9 pm. Visibilities will lowering rapidly to 1 mile or less as the snow moves in. Due to the very cold temperatures, the snow will be quite fine and light, which will make it easy to drift and blow around if winds pick up. 3 to 5 cm of snow is expected by Wednesday morning with this system.. so be prepared for another slow commute into work tomorrow morning.

Monday, November 26, 2007

Snow and cold on the way..

A little more snow on the way today.. Turning colder tonight. More snow Tuesday night.

A weak clipper system over southwest MB this morning will track across North Dakota today bringing an area snow across southern MB. The snow has spread into the Portage area as of 10 am and will move into Winnipeg by midday. About 2 cm of snow can be expected this afternoon before the snow ends, with poor visibility at times and locally slippery driving conditions especially south and west of Winnipeg where the snow may be heavier at times. As the snow ends later today, brisk northerly winds will develop bringing in a surge of colder air from central MB where temperatures are currently in the minus 20s.  Cold air will flood across southern MB tonight with wind chills dropping to the -30 range. Tuesday will start off clear and cold but another Alberta clipper system will spread cloud in during the day with another batch of snow developing from the west by afternoon. Look for this snow to spread into Winnipeg by Tuesday evening, with another 3 to 5 cm of snow likely Tuesday night into early Wednesday. As this system moves east, cold air will once again be reinforced across southern MB for the end of the week.  Like it or not.. winter has arrived in southern MB.   

Sunday, November 25, 2007

Get ready for some COLD weather this week!

Yikes.. I'm not liking what the upcoming week looks like over Southern MB. Very cold air will be flooding in by late Monday, and it looks like it'll be here for awhile.. at least through the end of the week, perhaps through next week as well. For today, southern MB will be under a frontal zone separating mild air to our south from frigid Arctic air to the north (lots of -30s this morning over Nrn MB and Nrn SK) Weak disturbances will move across this frontal zone today into tonight giving southern MB a few cm of snow through the period. (In fact, snow will be spreading into Winnipeg by 9 am or so this morning from the northwest with lowering visibilities) On Monday, the frontal zone is forecast to shift south of us, which will allow the cold air from the northern Prairies to begin flooding in. The cold air will be well entrenched over southern MB by Monday night with temperatures dropping into the minus 20s, and highs on Tuesday only in the minus teens. Little relief is expected the rest of the week, although it should remain generally snow free. After such a mild and tame start to winter, this upcoming cold weather will come as a bit of a shock to residents of southern MB used to the mild weather. Break out the heavy winter gear!

Friday, November 23, 2007

Where's the snow?

We had another light dusting of snow today in Winnipeg, but nothing much.. perhaps a cm or so. Snowfall has been quite meager so far this season, with only about 5 cm of snow so far this month. Average November snowfall in Winnipeg is around 21 cm so we are running well below normal with only one week left in the month and little in the way of major snowbearing systems in the long range outlook. However, this is on par for what's been happening over the past decade, with 9 of our past 10 Novembers recording below normal snowfall for the month. Looking back even further, there have been several Novembers in Winnipeg with minimal snowfall. Below is a list of the top 10 least snowy Novembers in Winnipeg since records began in 1872.

YEAR...........SNOWFALL (CM)

1928 .................... TR
1939 .............
...... 0.5
1987.................... 1.0
1901.................... 1.5
1976 ................... 1.5
1912 ................... 2.5
1981 ................... 2.5
1916 ................... 2.8
1982 ................... 3.2
1913 ................... 4.1
1961 ...................

So does this slow start to the snow season mean anything for December? Well, if we look at the top 20 least snowy Novembers in Winnipeg, 14 (70%) were followed by below normal snowfall in December, 4 (20%) had near normal snowfall, and only 2 (10%) had above normal snowfall in December. So, based solely on this crude analog method, history would suggest that snowfall this December will likely also be below normal. But before you put away the snow shovel.. remember that each year is different, and there is no guarantee this correlation will work this year. It only takes one major storm to skew the statistics. Also, of the years noted above, only one year since 1950 was a La Nina year (1961).. and that year December had above normal snowfall. I merely present these stats for what they are.. interesting but not necessarily a reliable predictor for this year. As they say in the mutual fund business.. Past performance does not guarantee future results :)

Wednesday, November 21, 2007

A cold night..

It's definitely feeling more like winter out there with the coldest weather in Winnipeg since last March. Highs today didn't climb above -7C and for tonight, temperatures are forecast to drop to a bone-chilling -19C. This would make it Winnipeg's coldest temperature since March 7.. over 8 months ago. And it looks like the cold weather will last for awhile, with below normal temperatures expected over the next week or two. Hard to believe that just last week, we were enjoying 17C temperatures! Still not a lot of snow on the horizon yet, but with these colder temperatures, it's only a matter of time!

Sunday, November 18, 2007

NOAA releases updated winter outlook

NOAA has released their final update of the winter outlook for the 2007-08 season.. and it continues to show a greater than even chance of warmer and drier than normal conditions over the southern US thanks to a developing La Nina. For Manitoba and the southern Prairies, the jury is still out as to what kind of winter we're going to have.. with no clear signal either way of how the winter will evolve. See my earlier post on the winter outlook for more details on how things may evolve for Southern MB this winter.

Updated warning page

I've updated my warning page to highlight weather warnings and watches more easily over southern MB. Clicking on the warning icon on the main page will access this page. It includes links to the actual text of the message which is sometimes slow to update on the Weatheroffice website.. especially in times of rapidly changing severe summer weather. Links to American warnings are also displayed.

Speaking of warnings.. a freezing rain warning has been issued for southwest MB this morning. A band of freezing rain and wet snow has moved into southwest MB from Saskatchewan and will affect those areas for a couple of hours this morning. The precipitation band is expected to move into Winnipeg and the Red River valley by midday. By that time, our temperatures should be above freezing so the precipitation should fall as rain or wet snow. However if our temperatures are still near or below freezing by that time, a brief period of freezing rain is also possible here.

Saturday, November 17, 2007

Updated Webcam Page

Just a note to let you know I have updated my webcam page to include a couple of new webcam images.. including St Andrews Airport just north of Winnipeg, a yard in East St Paul (north end of Winnipeg), and a webcam from Strathclair out in western MB just to the south of the Riding Mtns near Clear Lake. Webcams are great tools to monitor local weather conditions, and to see how that snowfall is progressing outside our little part of the world!

Some wet snow Sunday?

A warm front is forecast to push across Southern MB on Sunday which will spread an area of wet snow and rain ahead of it. For Winnipeg, it looks like the precipitation will start off in the morning as a period of wet snow that will change to rain before ending in the afternoon. Current forecasts call for up to 5 cm of snow in Winnipeg, but this seems a little on the high side for this situation. I've been noticing that the GEM model, which drives the local forecast, has been overdoing snow amounts with warm fronts over southern MB so far this season, at least here in Winnipeg. Typically, we don't get a lot of snow with warm fronts, as the band of precipitation is usually fairly narrow and moves through quickly which limits snowfall accumulation. In addition, we have southerly winds tomorrow which will bring above freezing temperatures in the lowest layers fairly quickly. As a result, I expect perhaps 1 or 2 cm of wet snow at most Sunday morning that will melt off in the afternoon as temperatures rise above freezing.

Whatever the case, this won't be a major snowstorm and snowlovers are getting anxious for a good snow to develop here in southern MB. The ground is still bare, and in many areas the grass is still green indicating ground temperatures are still above freezing. And long range models are not indicating any major snowbearing systems through next week over southern MB. Things can change of course, but at this point, it appears that November 2007 is following the trend of most of our winters over the past decade.. a slow start with below normal snowfall to start off the season. Could this be our new normal?

Tuesday, November 13, 2007

Record high!

Winnipeg has hit a record 17C today.. eclipsing the former daily high of 16.3 set back in 1999. We are currently the warmest spot in the country and it's only 11am!  But a cold front will push through by the lunch hour, and temperatures will begin sliding down this afternoon, while winds will be picking up from the west, with gusts to 80 km/h or more this afternoon. Watch out for flying garbage cans! 

Monday, November 12, 2007

Marvelous Monday almost sets record

It was a beautiful Nov 12th over Southern MB, with sunshine and a balmy southwest breeze sending temperatures into the teens across the area. Today's high in Winnipeg was a balmy 12.8C, nearly beating the daily record high of 13.2C set in 1981. These temperatures were more typical of early October than mid November, which now averages around the freezing mark for "normal" highs. The lack of snow and still warm ground has made it easier for mild air to surface, and it's still hard to believe that it's really mid November out there. The grass is still green, and it just doesn't feel like winter will be here anytime soon. But don't be fooled.. this is southern Manitoba.. and things can change quickly!

Speaking of which.. there will be a change in the weather over the next few days, although the main story will be winds, not snow. A deep storm system moving across the northern Prairies will draw strong southerly winds to 60 km/h over southern MB Tuesday morning, shifting to strong westerly winds to 70 km/h or higher in the afternoon as a cold front moves through. Temperatures will once again be very mild Tuesday with highs peaking around 13C by midday.. but then watch for falling temperatures by Tuesday night as colder air moves in from the west. Strong northwest winds will continue Tuesday night through Wednesday along with temperatures near freezing. There could be some flurries Tuesday night and Wednesday, but at this point, there's still no signs of a significant snowfall over southern MB over the next week or so.

Sunday, November 11, 2007

Strong winds Tuesday and Wednesday

It was a windy afternoon today in Southern MB, and after diminishing tonight, it looks like strong winds will once again develop this week.. (hey, it's the Prairies in the winter, what else is new? ;)) especially Tuesday and Wednesday. But first, we'll start the week on a nice note on Monday as mild weather continues, along with plenty of sunshine and fairly light winds (southwest 20 km/h) This should get temperatures up to the 10C mark once again... nice enough for one last golf game on any course still open. By Tuesday, a deep low pressure system tracking through the northern Prairies will bring a strong southerly flow over Southern MB, especially up the Red River valley where gusts may hit 70 km/h. Winds will gradually shift into the west by Tuesday evening as cooler air moves in, with strong northwest winds and colder temperatures for Wednesday. Lighter winds but cool conditions are expected to close off the week for Thursday and Friday.

Mild Remembrance Day

Temperatures have risen up to the 10C mark in Winnipeg as of noon today, with a few hours of sunshine and gusty west winds allowing temperatures to climb. It won't be a record breaker (14.8C in 1987 is Winnipeg's mildest Remembrance Day on record) but it will be some 10 degrees above above normal for today. The main story for this afternoon will be the gusty west winds, which will gust to 60 or 70 km/h today as cooler air and clouds spread in from the west. (Brandon currently gusting to 74 km/has of noon) As a result, look for those temperatures to gradually slide this afternoon down into the 5C range by sunset.

Friday, November 09, 2007

More snow tonight?

A warm front is forecast to move across southern MB overnight bringing a band of snow ahead of it. At this point, it appears most of the snow will once again stay mainly north of Winnipeg - much like Thursday night - with a few cm possible across the Riding Mtns through the interlake and Whiteshell areas. Winnipeg may see a few flurries overnight into Saturday morning, but accumulations should be minimal. By Saturday afternoon gusty southerly winds will usher in milder air over Winnipeg with temperatures rising to +4C. Even milder conditions are expected for Sunday with highs near +7C, however there could be a few morning showers giving way to brisk westerly winds by the afternoon.

Rare thundersnow hits Winnipeg Thursday night

A rare occurrence of "thundersnow" occurred in Winnipeg last night as a weather system tracked across Southern MB, bringing the season's first general snowfall mainly north and east of Winnipeg. Around 11:45 pm a band of wet snow was moving through Winnipeg when a sudden flash of lightning generated a very loud thunderclap that some people mistook for an explosion. I was awoken by the thunder myself, and it was as loud as any close by summertime lightning strike, yet it was +1 and snowing at the time. I didn't see the flash, but many people reported one. Data from the lightning detector network indicates that the strike hit somewhere near the Eldridge/Oakdale area of Charleswood and generated 104,000 amps of electricity, which is a very powerful stroke. (normal lightning strikes generate about 20-40,000 amps) Note that this was the only strike recorded last night.. almost like the cloud built up all this static electricity, then released it all at once right over Charleswood! By the way, thunder is very rare around these parts during the cold season, with only 4 official occurrences between November and March in the last 50 years at Winnipeg Airport.

Thursday, November 08, 2007

A little snow on the way tonight?

A weak system over Saskatchewan is forecast to spread an area of snow into southern MB today which will move into the Winnipeg area by this afternoon or evening.  Radar shows some light snow moving into western MB from Saskatchewan this morning.  The snow will likely be melting on contact with the ground by the time it reaches Winnipeg as temperatures will be above freezing. There's even a chance the precipitation will mix with light rain if temperatures get warm enough (around +3 or +4C) For tonight, temperatures should remain steady near the freezing/melting point, so any snow that falls will likely be melting however we could see a slushy accumulation of 1 or 2 cm mainly on grassy surfaces tonight. There's a better chance of some accumulating snow north of Winnipeg through the Interlake areas where temperatures will be a little cooler and the main precipitation axis is forecast. The system is expected to exit southern MB overnight with drier conditions for Friday.  

Saturday, November 03, 2007

First snowfall arriving Sunday?

As I mentioned a couple of days ago, it looks like Winnipeg and much of Southern MB may be seeing the first general snowfall of the season by Sunday night. An Alberta clipper system will track across southern MB on Sunday bringing an area of snow with it. Precipitation will move into western Manitoba from Saskatchewan Sunday morning, reaching Winnipeg by afternoon. Precipitation in Winnipeg may start off as a mix of rain and wet snow at first, but will change to all snow by evening as colder air moves in. The snow may fall heavily for a time Sunday evening before ending overnight. Accumulations of 2 to 5 cm are possible, but some of that will melt due to the still warm ground. Colder air will sweep in behind the system Sunday night into Monday, with temperatures falling below freezing. As a result, there could be some icy driving conditions for early Monday.

Thursday, November 01, 2007

Noel strengthens to hurricane status - heading towards Nova Scotia

Tropical storm Noel strengthened into a Category 1 hurricane Thursday evening with maximum sustained winds of 70 kt (130 km/h) The storm, which has lashed the Caribbean and Bahamas with heavy rain and deadly flooding, is moving northward and will continue up the Gulf Stream heading towards Nova Scotia this weekend. The storm is expected to lose its hurricane status on Friday as it heads north, but it will evolve into a large intense "extra-tropical" storm system that is forecast to make a direct hit on southwest Nova Scotia late Saturday. The storm will bring powerful winds to Nova Scotia Saturday into Saturday night, with near hurricane force winds possible especially along the Atlantic shoreline with damage possible to trees and power lines. Heavy rain is also likely especially to the west of the storm track over New Brunswick. This will be an interesting storm to monitor over the next few days, as the remnants of Noel track across the Maritimes.

Some links to monitor the progress of Noel..

NOAA Hurricane Center
Canadian Hurricane Center
Halifax Radar
Boston Radar
Cape Cod Weather
Halifax Herald

First taste of winter moving in next week..

Get ready for our first blast of cold air this season by early next week. A developing low pressure system over the Pacific will move across southern AB and track across the southern Prairies Sunday into Sunday night. This system will bring cold northwest winds behind it which will sweep across southern MB Sunday night into Monday. The cold air will be well entrenched across southern MB Monday and Tuesday with daily highs struggling to get above freezing, along with cold northwest winds. In addition guidance suggests this system has the potential to bring the season's first accumulating snow across southern MB Sunday night depending on the eventual track of this system. Models bring an east-west swath of snow anywhere from North Dakota through central MB, with local amounts of 5 cm possible.

Dry but cool weather is expected through the middle of next week before a potential for another snowfall late next week into next weekend. Looks like winter will finally be making an appearance next week over Southern MB!

Sunday, October 28, 2007

Halloween Outlook

It's looking more likely that Halloween this Wednesday will be a chilly but dry evening. Models are indicating that Wednesday will start off blustery and cold with gusty northwest winds behind an intensifying low pressure system tracking into NW Ontario. This system could bring some rainfall to southern MB Tuesday night which may even mix with some wet snow overnight before ending early Wednesday morning. The rest of the day should see cloudy and windy conditions with below normal temperatures around +3C or so. A ridge of high pressure building in by evening should bring clearing skies as well as lighter winds to the Red River valley, but temperatures will likely be near the freezing mark by then. All in all, not a bad looking evening for the trick or treaters at this point. I will post updates as we get closer to Wednesday..

Saturday, October 27, 2007

Growing season officially ends downtown

It took awhile, but the 2007 growing season officially ended this morning for downtown Winnipeg, with the Forks weather station recording a low of -1C. This is the first freezing temperature at the downtown site since April 17th when a low of -0.4C was recorded, giving the downtown core a growing season this year of a whopping 192 days.. or over 6 months. This has been evident with the abundance of flowers and even some vegetable gardens still living in many areas of the city, especially downtown.

Contrast this to the Winnipeg airport site, which had a frost as late as May 27th (-0.1c) and as early as Sept 14th (-1.4c) for a growing season of only 108 days, almost half the length of downtown. This shows the large difference in nighttime temperatures between the more open rural areas around the egde of the city, and the more urbanized downtown core.

Here at my station in Charleswood, the official growing season lasted from Apr 26th to Oct 14th, or 142 days.. a good average for the city in general. This just goes to show how basing the growing season solely on the Winnipeg airport site can be very misleading!

Wednesday, October 24, 2007

Gusty south winds bringing milder air in..

Strong southerly winds over southern MB are bringing in milder temperatures tonight which will persist into Thursday. Those southerly winds are particularly strong over Winnipeg and the Red River valley tonight with gusts to 60 km/h due to funnelling effects up the Red River valley. This will keep temperatures from falling much below the 10 degree mark tonight.. our normal high for this time of year. On Thursday, gusty southerly winds in the morning will diminish by afternoon and switch into the northwest as a cold front moves through. Temperatures however will climb into the upper teens by early afternoon before the cooler airmass arrives by evening. Note that this same airmass produced record highs in the 25c range over southern AB and southern SK today.

Monday, October 22, 2007

Windy week ahead..

A weak weather system will track into central MB tonight and into northwest Ontario Tuesday morning. This system will bring a few showers through the northern interlake and central MB regions tonight possibly mixing with some wet snow in places. As the system tracks into northwest Ontario Tuesday morning, gusty northwest winds will develop behind the system over southern MB with northwest winds of 40 to 60 km/h possible through midday Tuesday.

By Wednesday a more potent system coming off the Pacific is forecast to track across far northern SK moving north of the MB/NU border on Thursday. This system is forecast to deepen into an intense storm over Hudson Bay on Thursday into Friday, with very strong northwest winds and blizzard conditions possible over the Hudson Bay coastline including Churchill and much of the Kivalliq region of Nunavut. South of this intensifying storm system, gusty south to southwest winds will bring milder conditions over the southern Prairies by Wednesday with temperatures climbing to the 20 degree mark over southern SK and southwest MB on Wednesday. Look for gusty southerly winds of 40 to 60 km/h or more over the Red River valley on Wednesday with highs in the mid teens. The milder weather will be short lived however as gusty northwest winds on the backside of the intense Hudson Bay storm drives cooler weather across the eastern Prairies for the end of the week.

Saturday, October 13, 2007


Skies finally cleared over Winnipeg early this morning after 8 straight days of clouds and gloomy weather. The cloud is still not that far away however this morning as the western edge of the cloud has moved just east of the city, with clouds persisting over southeastern Manitoba in areas like Steinbach and the Whiteshell. A disturbance in Saskatchewan will bring some cloud back in tonight into Sunday morning over the Red River valley, however this higher level cloud should clear out by Sunday afternoon.

Rob's Weekend Forecast for Winnipeg..

TODAY.. Morning fog patches with locally dense fog giving near zero visibility at times. Otherwise mainly sunny and a lot more pleasant today than recent days. Little or no wind. Highs around 14c.
TONIGHT.. Increasing clouds. Calm winds. Lows near zero.
SUNDAY.. Slight chance of a morning shower otherwise morning clouds giving way to sunshine. Light winds. Highs near 14C.

Wednesday, October 10, 2007

NOAA releases winter outlook

NOAA has just released their official winter outlook for the US. Their forecast calls for generally above normal temperatures over the US south and southeast and generally wetter than normal conditions over the Ohio Valley and Pacific Northwest. This is in response to the developing La Nina which would tend to produce below normal heights (trough) off the West Coast and above normal heights (ridge) over the southeast US with a storm track riding from the US west coast into the Great Lakes.

For the northern Plains/southern Prairies.. there is essentially an equal chance of either below/near or above normal conditions this winter.. i.e. a non-forecast. In other words, there is no clear signal how this year's La Nina will affect the southern Prairies one way or the other. If indeed the general synoptic pattern sets up as described above, then there would be a greater likelihood of below normal temperatures this winter over the Prairies, especially the western Pariries, with perhaps above normal snowfall over the eastern Prairies closer to the storm track.

Here in Winnipeg, our last extended La Nina occurred from mid 1998 to early 2001. During those winters,

1998-99… generally warmer than normal.. especially February and March.
1999-2000.. Generally much above normal..with near normal January. (snowcover was gone here by end of February)
2000-01... A real see-saw winter. Third coldest December on record, followed by a mild January then cold February
2001-02.. Generally warmer than normal, cold March

So as you can see, La Nina doesn't necessarily equate to a cold winter here, at least in the eastern Prairies. One also has to consider the remarkably low Arctic sea ice cover recorded this year (an all time low), which presumably would tend to delay the onset of deep and persistent Arctic airmasses in the far north. That could mean a delayed start to winter over the Prairies, before colder than normal conditions set up for the latter half of the winter, mainly over the western Prairies. If that storm track is further north, then Alberta could see a snowier than normal winter with storms off the Pacific, with above normal temperatures more likely over the eastern Prairies.

A TV meteorologist in the US has produced an analog map showing temperature/precip anomalies based on previous La Nina years back to 1950. It supports above normal temperatures in the southeast US, and colder than normal temperatures over the north/northwest US including the southern Prairies.

So there are hints that perhaps we'll see colder than normal conditions at some point this winter, but there are also conflicting signals that reduce confidence in this outlook, especially in light of warming trends in our winters over the past decade and this year's record low Arctic ice cover.

NOAA will update their winter outlook on October 18th and Nov 15th.

Where's the sun?

It's been a dreary few days over Winnipeg and Southern MB with generally overcast skies and cool conditions, as well as that washout of a Thanksgiving Monday. Our last sunny day was last Thursday (Oct 4th) which helped boost temperatures to 18C. Since then, afternoon temperatures have generally been stuck between 5 and 10c under overcast skies. Here in Winnipeg we had some brief sunny breaks Sunday morning (7th) otherwise, it's been overcast since last Friday. But that isn't unusual for this time of year as cool air begins flooding over the Prairies with still relatively warm ground and open lakes providing low level moisture. As a result, quite often you can get several days of cool cloudy weather during these months even in high pressure ridges (known as "dirty" highs in these cases) We're in such a period right now, and it looks like we'll stay cloudy through Friday before we get a better chance of some sunshine this weekend.

Sunday, October 07, 2007

Significant rain possible over SE MB Monday

A new storm system developing over Minnesota will track into Northwest Ontario Monday and intensify. Significant rain is expected to develop on the northwest wide of this storm system, affecting much of southeast MB and the Red River valley Monday including Winnipeg. 20 to 30 mm of rain is possible over southeast MB with little or no rain expected west of the Red River valley. In addition, it will be quite cool as northwest winds tap some colder air aloft, bringing temperatures down to the 5c mark by afternoon. A good day to stay inside and enjoy some Thanksgiving leftovers!

Thursday, October 04, 2007

Thanksgiving weekend outlook

A slow moving complex area of low pressure developing over the central American Plains will give a mixed bag of weather over southern MB this holiday weekend. Models have been struggling to find a consistent solution with this upcoming system, which explains the large swings and flip flops in the forecast this weekend. Initially it appeared as if this system would bring a prolonged period of rain over southern MB through the weekend. It now looks like much of the rain will fall over southern SK and southwest MB Friday into Saturday before moving into the rest of southern MB Saturday night into Sunday. At this point, the bulk of the weekend rain is expected through southwestern MB and the interlake (perhaps 20 -30 mm), with lesser amounts expected over the Red River valley and southeast MB (5-15 mm)

Saturday looks interesting as the storm system sharpens over the US midwest sending a pronounced warm frontal tough towards southern MB. This warm front will mark the leading edge of much warmer air which will be surging north into North Dakota and Minnesota on Saturday. The front may push into extreme southeast MB on Saturday with 25C temperatures possible along the US border. At this point, it appears Winnipeg will stay on the cool side of this front with temperatures in the mid teens. However if the front pushes far enough north Saturday afternoon, Winnipeg may get into the low 20s (as current forecasts suggest) The frontal trough will move east Saturday night into Sunday with showers and possible thunderstorms over southern MB with locally heavy rain possible. Another system threatens showers for Monday.

Summing up.. unsettled Saturday with showers over southwest MB and the interlake - drier with a warming trend over southeast MB. Showers and thunderstorms Saturday night with locally heavy rain possible. Showers ending Sunday. A few showers possible Monday. Have a good long weekend whatever the weather!

Rob's Obs humidity/dew point values

I installed a new temperature and humidity sensor on my Davis weather station today.. hopefully that will give more reliable humidity and dew point values now. So far values look good, but I will continue to monitor over the next few days to make sure readings are reliable.

Saturday, September 29, 2007

Windy warm day in store..

We've had a pretty good run of nice weekends here in Southern MB in September, with some of the warmest days this month falling on the weekends. And it looks like we'll have another nice day today with gusty southerly winds sending temperatures into the mid twenties.. some 10 degrees above normal for the end of September. Those southerly winds will increase by early afternoon with gusts to 60 km/h likely especially through the Red River valley which tends to funnel southerly winds. That should strip off a few more leaves today! A cold front will move through tonight bringing possible showers with clearing and cooler, but still pleasant conditions for Sunday. Nice weather should continue into the first few days of October. Get out and enjoy these last nice days of autumn! (hopefully we get a few more in October.. and even November!)

Monday, September 24, 2007

Heavy rain finally hits Winnipeg

A band of showers and thunderstorms brought locally heavy rain to the Winnipeg area last night, resulting in the most significant rainfall in many areas since July 25th. Much of the city picked up at least 20 mm of rain, most of it falling around 1 am with thunderstorms. At my station, I picked up 22 mm of rain with a peak rainfall intensity of 80 mm/hr at 1 am. Here is a roundup of Winnipeg and area rainfall amounts since midnight. (All but the Forks are unofficial amounts from local private weather stations.)

East St Paul........................ 27 mm
Sanford........................... 26.9 mm
Downtown (U of W)..............25.1 mm
Selkirk.............................22.9 mm
Charleswood (Rob's Obs)...... 22.1 mm
St Vital........................... 21.6 mm
Downtown (Forks) ..............20.0 mm
U of M ag station ............... 19.8 mm
Transcona........................... 18.9 mm
River Heights..................... 18.8 mm
Charleswood (PJ school)....... 18.3 mm
Whyte Ridge.......................... 16.0 mm
Winnipeg Deer Lodge ........... 15.7 mm
Fort Whyte Center................ 15.2 mm
Bird's Hill................................. 10.8 mm
Stonewall............................... 7.6 mm

Sunday, September 23, 2007

Summerlike Sunday - part 2

For the second Sunday in a row, summerlike temperatures spread into Southern MB, with 30 degree heat along the US border. Emerson was the national hot spot with a sizzling 32.4C temperature as of 5 pm, with Sprague and Gretna registering 31C temperatures. Winnipeg was also on its way to possibly hitting 30C today, but a cold front came through around 3 pm, with winds shifting into the northeast bringing cooler air from the interlake, knocking temperatures down from 27C to 22c between 3 and 4 pm.

For tonight a band of showers and possible thunderstorms is expected to move across southern MB from the southwest. Models are suggesting between 10 and 20 mm of rain over much of the Red River valley by morning including Winnipeg with some locally heavy rain at times thanks to embedded shower or thunderstorm activity moving up from North Dakota. Hopefully, this rain materializes and doesn't miss us, as has been the case the past couple of months. Look for a blustery and much cooler day Monday with cloudy skies, occasional light rain or drizzle, and temperatures only around 10C. Welcome to the roller coaster weather of fall!

Wednesday, September 19, 2007

Some much needed rain Thursday?

A weather system tracking across the northern US plains will spread an area of showers across southern MB on Thursday hopefully bringing some much needed rainfall to the south Winnipeg area. Current indications are that between 5 to 10 mm of rain is expected across Winnipeg, although some model solutions indicate as much as 20 mm of rain is possible (more likely with embedded thunderstorms) . This would be most welcome across southern Winnipeg which has been very dry since late July. Lawns here are brown and cracked with a severe lack of subsoil moisture. Here in Charleswood, I've only recorded 26 mm of rain since August 1, with no single rainfall over 5 mm over that time. The last time we had more than 5 mm of rain at one time was way back on July 25th during a heavy thunderstorm when 18 mm fell. So a little rain Thursday wouldn't be such a bad thing..we could sure use it.

Tuesday, September 18, 2007

Elie, MB tornado reclassified as Canada's first official F5 tornado

The Elie, MB tornado of June 22, 2007 (image left) has been re-classified as an F5 tornado, upgraded from its original F4 rating. This makes the Elie tornado Canada's first officially documented F5 tornado. The re-classification was based on re-analysis of the video data, including video of a home being completely swept off its foundation and obliterated in mid air as well as a heavily loaded van being thrown a considerable distance. (see video here) According to the Fujita tornado rating scale, this type of damage is consistent with an F5 tornado with wind speeds of 400-500 km/h. For further details on the Elie, MB tornado.. see my earlier June blog entries.

Note that tornado ratings are based on the most intense damage found within the track of that tornado. It doesn't mean the tornado was always at F5 strength, but that it reached F5 at its maximum intensity. Note also that tornado strength is based on physical damage caused by the tornado. If a powerful tornado doesn't hit or damage anything, than it can only be classified as an F0 tornado.. no matter how strong it really may have been. As a result, there may have been other tornadoes in Canada that were F5 strength at some point, but they didn't hit any structures during that time to warrant an F5 rating. The Pipestone tornado that hit a day after Elie is a good example of this. This monster tornado is officially rated as an F3, however it didn't hit anything structural at its maximum intensity, staying mostly over open fields and forests at its height (good thing too!)

"Rob's Obs" humidity/dew point readings

Just a note to advise you that I'm currently experiencing problems with my humidity and dew point readings from my weather station. They are registering way too low compared to actual conditions. For example, today we are seeing humidity values around 95-100% around Winnipeg but my station is showing only 50%. Also, since dew points are calculated from the humidity reading, they are also too low. I've ordered a new temperature/humidity sensor that should fix the problem, but that will take a couple of weeks or so before I get it. Until then, ignore my humidity readings, and check on nearby Pacific Junction school for more accurate Charleswood humidity values.

Monday, September 17, 2007

Another nice day.. cooler Tuesday

It was another balmy summer-like day over southern MB with sunshine and temperatures in the mid 20s along with dewpoints in the upper teens. The warm weather however will come to end Tuesday as northerly winds develop bringing considerably cooler air southward. That cool air was evident over central MB and the northern Interlake today with temperatures only around 10C this afternoon in Swan River under overcast skies. That cool air should be moving into Winnipeg Tuesday morning with afternoon temperatures likely only in the mid teens - some 10 degrees cooler than today's mid twenty values. Currently, the forecast high for Winnipeg on Tuesday is 22c which looks a little optimistic from what I'm seeing. Don't be surprised to see that forecast high revised downward by tomorrow.

Sunday, September 16, 2007

Summer like Sunday!

Wow.. what a turnaround from the cold just a couple days ago. Temperatures soared to a surprisingly warm 30 degrees in Winnipeg this afternoon, with a gusty southwest wind aiding in the warmup. At 3 pm the temperature at Winnipeg airport shot up to 30 degrees (29.9C officially) while the humidity dropped to 17% as the dewpoint went from 10 to 2c. Almost desert-like air! What a nice surprise as I thought we were done with 30C temperatures for the year. For the record, last year we had our last 30C temperature on Sept 15th, so we went one day better this year!

Arctic sea ice at record low levels

Interesting article in today's paper about how ice cover over the Arctic is at its lowest level on record this year. Ice cover has shrunk to about 3 million square km, a million square kilometres less than the previous record lowest year in 2005. Data from the US's National Snow and Ice data Center give slightly different numbers.. showing ice coverage at 4.2 million sq km as of Sept 10th, still the lowest on record (previous record low was 5.3 million sq km in Sept 2005) Whatever the case, it's an amazing stat.. and certainly lends strong support to the global warming theory that has always warned of this consequence. Note however that these reliable ice cover records only go back to 1978 which is not a very long record to make any definite conclusions. One has to wonder what Arctic ice cover levels were like in the years before 1978, especially in the 1930s and 40s when we had some very extreme weather, and some very mild winters.

Nonetheless, you have to figure something is definitely changing up in the Arctic, and a continual reduction of the Arctic ice cover will have major impacts on our climate, sea levels, and economy (with the possible annual use of the Northwest passage) One of the impacts of a reduced Arctic ice cap is that winters would generally be starting later, and we have certainly seen this in southern MB with 8 of our past 10 Decembers warmer than average. So it does appear that we're already seeing some impacts of this exceptional loss of Arctic ice with delayed, shorter, and less severe winters.

It's interesting to note that Winnipeg had its warmest January on record in 2006, following the last record low Arctic ice cover in the fall of 2005. Will this mean we will have another record mild winter this year? Well, it's tough to say since there are other factors which can influence our winters such as a developing La Nina, and other global climatic oscillations. However, one has to certainly consider that there is a good possibility of another warm winter coming up for Southern MB given this year's amazing loss of Arctic sea ice.

Thursday, September 13, 2007

Lake effect rainbands affecting Winnipeg and area

A band of lake effect rain has developed off Lake Manitoba this morning and is currently affecting parts of west Winnipeg. Cool air (0c at 850 mb) flowing over the warm open waters of the MB lakes (16-18c) has created these bands of lake effect precipitation which should persist this afternoon into tonight. Currently low level winds are from a 300 degree orientation which is advecting the band into west Winnipeg and areas northwest. Rosser has picked up 4 mm of rain this morning underneath the band. Outside the band, the sun is shining in parts of Winnipeg!

For this afternoon and evening, models indicate low level steering winds should become more northerly, with a 330-350 orientation which should push the Lake Manitoba bands westward through Elie and Sanford and areas west. A 330-340 band off Lake Winnipeg would affect the Patricia Beach and Beausejour areas. (see example of 330 degree squalls from last October) I expect the bands to intensify this evening and tonight off both Lake Manitoba and Lake Winnipeg as a cold pool of -5C air at 850 mb moves over southern MB. This will give a 20C temperature differential between the lake water and 850 mb temperatures, which is getting extreme for lake effect precipitation (you need a minimum differential of 13c for lake effect initiation). There's even a chance that the precipitation could mix with or change to wet snow tonight into Friday morning, although I suspect the warm lake waters should maintain the precipitation mainly as rain.

The good news is that we should see a moderating trend this weekend with dry conditions and warmer temperatures as this cold pocket of air moves east.


Lake effect update.. Interesting to see squalls starting to re-orient themsleves this afternoon as low level winds become more northerly. The 300 degree rainbands off Lake Manitoba which had been affecting Winnipeg are now weakening, while a new 330-340 band sets up further west between Elie and Portage. See attached Doppler radar image from 12:20 pm showing this lake effect transition in progress. Note also lake effect bands starting to develop off Lake Winnipeg.

Wednesday, September 12, 2007

Another cold blast coming in..

After a brief reprieve today with temperatures close to or over the 20 degree mark over Southern MB, a cold front will push through this evening bringing in much cooler air for Thursday. Brisk northwest winds on Thursday along with cloudy skies will keep temperatures only in the single digits most of the day, with afternoon highs struggling to hit the 10c mark. There will be occasional showers as well, although amounts should be on the light side here with the bulk of the rain falling through the interlake.

Thursday night will be downright cold as 850 mb temperatures plunge to -5C. This will be cold enough to possibly generate.. wait for it.. SNOW, especially over higher elevations of Southern MB! In addition, the cold air moving over the warm lake waters (currently running around 16 to 18C over the south basins) will generate bands of lake effect precipitation to the south and southeast of Lakes Manitoba and Winnipeg Thursday night into Friday morning. The warm lake waters should keep the lake effect precipitation as rain, however there is a chance that if the instability is deep enough and the bands are intense, the lake effect precipitation could change to wet snow.

Yikes.. a little too early to be talking about the S word!

Tuesday, September 11, 2007

Unseasonably cool day

Brisk northwest winds have ushered in an unseasonably cool airmass over Southern MB today with temperatures only in the single digits early this afternoon. Normal highs for this time of year are around 18-19C, so we're a good 10 degrees below "normal". With an expected high of only 11c this afternoon, this will be only a couple degrees above the coldest high ever for Sept 11th which was 8.9C back in 1890. (NOTE: this is corrected from an earlier post, which incorrectly stated the coldest Sept 11 was 15.6C back in 1949.. I was looking at the wrong column!) The cool northerly winds have even produced some bands of lake effect rainshowers off Lakes Manitoba and Winnipeg with Beausejour picking up 1.5 mm of rain off Lake Winnipeg this morning.

With such a cool airmass in place, it would seem likely that frost would be a concern for tonight.. However, a storm system from the west is expected to bring increasing clouds overnight with increasing southeasterly winds that should minimize the threat of frost over southern MB tonight. However, look for a chilly evening with patchy frost possible mainly east of Winnipeg. This storm system by the way may bring the season's first snowfall over central AB and SK tonight through Wednesday night!

No doubt about it.. fall is here!

Thursday, September 06, 2007

PJ weather station back online..

Well, school's back.. and so is the PJ weather station.. another Charleswood area weather site. The station is located on the roof of Pacific Junction School on Cathcart Ave next to the Assiniboine Forest south of Grant. The station is a good alternate site to Rob's Obs for real time weather data in Charleswood. Note the PJ site has better exposure on top of the roof, so wind readings from their station are more accurate than mine, which tends to register on the low side due to the sheltering effects of houses and trees.

Thursday, August 30, 2007

Summer's last hurrah?

Looks like a nice stretch of summerlike weather coming up to cap off the last unofficial weekend of summer. Balmy southwest winds and sunshine are boosting temperatures into the upper 20s today over southern MB, and we will likely be hitting the 30 degree mark Friday and Saturday before a cold front moves through Saturday night. Sunday will be a little cooler with highs in the low to mid twenties, but with sunshine and light winds, it should still be a nice day. A system passing through the Dakotas threatens a few showers by holiday Monday. All in all though, it looks like a nice end to summer!

Tuesday, August 28, 2007

CWB sites added

I've added a link to get real time weather data from the new Canadian Wheat Board (CWB) weather network that has recently been launched in collaboration with Weatherbug. The stations can be found in a drop down list under the "CWB sites" link to the right of the precipitation comparison section on my main home page (under "other sites") Note that CWB also has a interactive map plot that plots CWB and EC weather sites in real time. This link can also be found under my "LINKS" drop down menu under "CWB sites".

This new CWB network of weather stations will be growing significantly over the next couple of years, with the goal of several hundred stations being set up across the Prairies at local agriculture sites, farms, schools, etc. See previous blog entry for further details on this initiative.

Sunday, August 26, 2007

Severe thunderstorms erupt south and east of Winnipeg

A cold front pushing through Southern MB triggered a line of severe thunderstorms Sunday evening just south and east of Winnipeg. It was a warm and humid day Sunday with temperatures climbing to 29C and dewpoints of 20C.. the warmest and muggiest day in a couple of weeks. This airmass provided the fuel for powerful thunderstorms to develop late in the day along a cold front moving in from the west. Toonie to golf ball size hail was reported with some of the storms as well as wind gusts to 100 km/h and a report of a funnel cloud south of Beasujour. The storms just missed hitting Winnipeg, with the cold front coming through dry here. However the impressive thunderstorm cells could easily be seen from the city, with majestic towering cumulonimbus tops rising to 50000 feet just 30 km away to the southeast.

Thursday, August 23, 2007

Feels like fall..

With grey skies and temperatures only in the teens, it's beginning to feel a lot like fall out there these days. After a steamy second half of July, August has been lacking in summer heat.. with only one day hitting the 30c mark (Aug 9th) Much of this month has seen temperatures near or slightly below normal, and the outlook looks like more of the same. The exception will be this weekend when temperatures are expected to climb to normal mid 20 values by Sunday. However, the warmup will be short lived as cooler air moves in by Monday, with below normal temperatures likely most of next week. In fact, long range guidance is suggesting much of southern MB may be seeing frost by next Wednesday or Thursday. After that, we're into September which can still have nice warm days, however any prolonged spells of heat appear to be over for 2007.

Tuesday, August 21, 2007

Dean slams into Mayan coast

Here's a great satellite image showing the eye of Category 5 Dean hitting the sparsely populated southern Yucatan coast just around 4:30am EDT near the port city of Majahual, Mexico, about 40 miles north of Chetumal, Mexico, a city of 130,000 just north of the Belize-Mexico border. Maximum sustained winds at landfall were near 165 mph with gusts approaching 200 mph. Dean became the first Category 5 hurricane to make landfall since Hurricane Andrew hit Florida in 1992. At 906 mb, Dean was also the third lowest pressure at landfall behind the 1935 Labor Day hurricane in the Florida Keys and Hurricane Gilbert of 1988 in Cancun Mexico.

As bad as this storm was, it could have been a lot worse had the storm come ashore about 100 miles north which would have caused billions of dollars in damage to the many resorts around Cozumel and Cancun.

Sunday, August 19, 2007

Dean approaching Jamaica..

Latest radar images from southern Cuba show the eye of Dean approaching Jamaica from the southeast. It appears that the eye is moving almost due west, which if that trend continues, will be good news for the city of Kingston as the core of the strongest winds in the vicinity of the eyewall will stay over the ocean just south of the city. There will still be very strong winds and damage to Kingston, but not as catastrophic had the eye passed over the city or just to its west. (see latest METAR obs from Kingston.) The southern coastline of Jamaica west of Kingston however may not be as lucky, as they may encounter the northern fringes of the eyewall and strongest winds. Should be interesting to see what happens over the next few hours..

Friday, August 17, 2007

Dean getting mean..

Look out.. Dean is up to a category 4 and latest hurricane hunter reports estimate max winds now up to 145 mph.. just 10 mph short of Cat 5 status. And there's nothing to stop this monster from getting even stronger over the next day or so as it heads towards Jamaica. Could be a major disaster there if this thing continues on its current track. After that, Dean is forecast to track towards the Yucatan Peninsula, then out over the Gulf of Mexico before making final landfall near the Texas/Mexico border (although there is still high uncertainty where this final landfall will be) Dean will be a major newsmaker over the next week or so. Stay tuned!

Thursday, August 16, 2007

New weather monitoring initiative announced

From the Winnipeg Free Press - A network of 600 private weather stations is expected to spring up on the Prairies within the next three years, providing invaluable information to farmers, grain merchants, flood forecasters -- and likely Environment Canada itself.

The new weather network, launched Wednesday by U.S.-based WeatherBug in partnership with the Canadian Wheat Board and James Richardson International (JRI), will provide clients with more localized weather information -- from temperature and wind speed to humidity and precipitation -- that will be updated every five seconds.

WeatherBug president Bob Marshall said Wednesday's launch, at a research farm owned by JRI just south of Winnipeg, is the first step in building a national network of more than 1,000 stations that will benefit farmers, schools, emergency managers, businesses and media outlets. "We have the technology to revolutionize the way weather information is gathered and shared in Canada," said Marshall, whose company operates 8,000 weather stations in the United States.

Click here for complete article.

Other links...
CWB weather station project website
CWB station map plot
Real time weather data from CWB rooftop station (includes webcam)

This is great news... a bold new private sector initiative to get lots of real time weather monitoring stations on the ground. This will help provide invaluable mesoscale weather information to fill in the gaps in Environment Canada's limited (and possibly shrinking) network of surface stations. The biggest benefit from this type of expanded network will be the ability to monitor real time rainfall measurements to the forecast and agricultural community, but local effects with wind and tempertaure will also be valuable information. Great to see! By the way, I see some of those Weatherbug weather stations are actually rebranded Davis Vantage Pro stations (which is what I have).

Wednesday, August 15, 2007

A taste of fall..

Enjoy the pleasant afternoon in Winnipeg.. because a cold front is approaching from the northwest with much cooler and windy conditions behind it. Temperatures behind the front in central MB are only around 14C with gusty northwest winds to 50 or 60 km/h. This front should be pushing through Winnipeg by late afternoon, so be prepared for a noticeably cooler and windy evening coming up! The front will usher in a fall like airmass that will be over southern MB for the next few days before a warmup over the weekend.

Tuesday, August 14, 2007

Some rain tonight.. for some..

A narrow band of rain is developing between Brandon and Dauphin and this band is expected to spread east through the night giving areas mainly north of Winnipeg about 10 to 15 mm of rain. Hopefully this band can settle south a bit and give some much needed rain to south Winnipeg where it's been very dry over the past 4 weeks, with only 3.6 mm of rain at my site so far this month. North Winnipeg has seen more rain thanks to some heavy thunderstorm activity over the past week or so that has dropped 20 to 40 mm of rain in those areas.

Monday, August 13, 2007

Flossie approaching Hawaii

Well, Hawaii and hurricanes are about as far as you can get from Manitoba weather, but our weather has been fairly quiet lately, so I thought I'd post some information on Flossie and the upcoming hurricane season. Flossie is still a strong F4 hurricane, even though it's approaching cooler ocean waters and more wind shear in the area. This has prompted a hurricane watch for the islands of Hawaii, with the storm expected to pass just south of the big island of Hilo. Should be interesting to see what happens over the next couple of days with this one.

This brings us to the upcoming Atlantic hurricane season which should become more active in the next few weeks. NOAA is still predicting an above average year for tropical storms, with 7-9 hurricanes predicted, 3-5 which could be categorized as major (at least Cat 3). As of today, a new tropical wave has developed off the African coast which could become the season's 4th named storm (Dean) over the next few days. For good information on what's developing in the tropics, I highly recommend Weather Underground's tropical website, and Dr Jeff Master's blog to keep abreast of the latest developments regarding tropical storm activity.

Friday, August 10, 2007

Severe storms slam Southern MB..

Strong long lived thunderstorms developed over east central Saskatchewan Thursday afternoon and tracked southeastward into the Lake of The Woods area by daybreak on Friday. These storms generated a large swath of golfball and larger hail from east central Saskatchewan into west central Manitoba late Thursday afternoon and evening then transformed into more severe winds as they continued tracking southeast from Lake Manitoba through Winnipeg and finally into the Lake of The Woods area during the overnight hours. The hail caused significant crop damage and several reports of windows smashed in houses and cars over west central Manitoba. (image shows sample of baseball size hail that fell in Dauphin)

The following are the preliminary severe events in Manitoba reported to Environment Canada up to 4 AM Friday.

Time of event location of event event type and comments
============= ================= =======================
4:05 PM .... Narol - Nickel sized hail
4:23 PM ..... pine ridge golf course - loonie sized hail
4:24 PM ..... Oakbank - Nickel sized hail
6:30 PM ..... 6 km west of San Clara - golfball sized hail
8:05 PM ..... Roblin - golfball sized hail
8:15 PM ..... 32 km nw of Dauphin - loonie sized hail
8:33 PM ..... Dauphin - 56 mm of rain in just over one hour.
8:44 PM ..... Dauphin - baseball sized hail. Extensive damage to cars, buildings and crops. Virtually every roof and car left outside in Dauphin suffered hail damage. Hail damage will likely exceed $50M. One of the most severe storms ever to affect area.
8:50 PM ... 8km south of Grandview - hen-egg sized hail.
9:20 PM .... Gilbert Plains - loonie sized hail.
9:35 PM .... Ste. Rose - Nickel sized hail.
10:15 PM ... 7 km east of Alonsa - golfball sized hail.
11:50 PM ... Delta beach - wind gust to 117 km/h.
1:15 to 1:30 AM .... Winnipeg - numerous reports of nickel to loonie sized hail and strong winds. Winnipeg airport had peak wind gusts of 100 km/h. Northern half of city was most affected with many trees down. One of the "top 10" storms for tree damage according to city forester. About 30 mm of rain fell over the north end of the city while areas south of Portage Ave received little or no rain.

Monday, August 06, 2007

A little rain on the way..

An area of rain over southwest MB is spreading into the Red River valley this afternoon, and should move into the Winnipeg area by mid to late afternoon. Rainfall amounts of 5-10 mm have been recorded over southwest MB, but amounts will likely be less over the Winnipeg area as the rainfall area weakens as it moves east. However there could be locally heavier amounts with some embedded thunderstorms that are possible this evening and tonight. It's been quite dry in Winnipeg since mid July, with only one main rain event over the past 3 weeks when 15-25 mm of rain fell during a heavy thunderstorm on July 25th. Soil moisture is quickly drying up, as evident by the cracking soil around my house. So a little rain would be most welcome..

Wednesday, August 01, 2007

July 2007 Highlights

Seasonable first half.. hot and dry second half..

July 2007 was marked by a distinct split personality.. the first half of the month featured generally normal temperatures and rainfall with no major extremes. The second half of the month however was marked by very hot and humid conditions and a lack of rainfall, with 2 heat waves to end the month that saw temperatures in the mid 30s and humidex values in the mid 40s. From the 17th to the 31st, the mean temperature at my location was 24C, some 4 degrees above normal. This compares to the first two weeks of the month which averaged a normal 20C. The result was a month that finished about two degrees above normal, but was considerably biased by the warm second half. The average high temperature in the last two weeks was a sizzling 31.3c, thanks to 8 days of 30+ temperatures, including a 35c reading on July 25th that was accompanied by Winnipeg's hottest humidex on record.. 48C thanks to a dewpoint of 26C at the time. The same day saw Carman, MB set a national humidex record of 53C thanks to an incredible 30c dewpoint.

Rainfall for the month was generally near normal with about 70 mm at my location (60 mm at Winnipeg airport). However, the rain was mainly concentrated in the first half of the month, with about 50 mm in the first two weeks spread over 5 or 6 rain events. The second half of the month saw only one rain event, when about 20-25 mm of rain fell during thunderstorms on the 25th that brought an end to the month's first heat wave. The hot dry weather has started to produce heat stress in area crops with depleting soil moisture, a considerable change from the wet conditions experienced during May and June.

All in all.. a sizzling end to a warm July.

Aaaaah-gust starts on refreshing note..

After another 3 days of high heat and humidity with dewpoints in the low to mid twenties, a cold front pushed through southern MB early this morning ushering in a much more comfortable airmass to start the month of August. Northwest winds are bringing in much drier air from the west, with dewpoints down to 10C over western Manitoba and single digits over Saskatchewan. This will result in much more comfortable conditions for the next few days with seasonably warm temperatures and plenty of sunshine. Long range models are indicating generally above normal temperatures for the first half of August over the southern Prairies with no signs yet of a major pattern change towards cooler or wetter conditions.

Tuesday, July 31, 2007

Another hot humid day... severe thunderstorms developing

July 2007 ended on another hot and humid day over southern MB with temperatures of 33-36C and dewpoints in the 22-26C range to produce humidex values of 43-48C. A cold front approaching from the northwest is producing a few intense thunderstorms mainly northwest of Winnipeg. The cell north of Gimli even showed signs of tornadic potential. Additional storms are likely through this evening and tonight as the front moves through southern MB. Some of these storms will be severe with strong winds, hail and torrential rain. The front will usher in less humid and more comfortable conditions across southern Mb for Wednesday.

Monday, July 30, 2007

West is burning

This satellite image taken Monday evening July 30 shows large smoke plumes from Montana forest fires spreading into southern SK and southern MB. Residents may have noticed a hazy appearance to the sky today, as well as a redder than usual sunset or sunrise. This is due to the presence of smoke particles spreading through a layer in the mid atmosphere, about 10000 ft or so. The smoke layer will likely persist over southern MB on Tuesday before a northwest flow clears out the smoke layer on Wednesday.

Note also several other smoke plumes from forest fires over western Montana and the BC/Alberta border.. a result of several weeks of hot dry weather that has baked the upper Rockies and western Prairies. Forest fires have also been a problem over northern MB as well this month.

Saturday, July 28, 2007

Heat rebuilding across southern Prairies

After a couple of days reprieve, hot weather is again returning to much of the southern Prairies this weekend, including southern MB. Temperatures in southern MB will hit the 30c mark again today with even hotter temperatures of 35c for Sunday into Tuesday. Fortunately, it looks like the humidity levels will not be as oppressive as last week's heat wave which saw dewpoints climb into the mid to upper twenties. Dewpoints over the next few days should be in the more moderate 15-20c range which combined with 35c temperatures will still make for uncomfortable conditions, with afternoon humidex readings in the 40-43c range. However, local areas such as the western Red River valley may once again see higher humidex values due to humidity input from crops (especially corn)

Wednesday, July 25, 2007

Record hot and humid day over Southern MB

Special weather statement from Environment Canada, Winnipeg - July 25 2007.. (graph showing heat index and dewpoints from Rob's Obs)




GILLAM 28.8 28.1 1983
PINAWA 34.3 34.0 1989
GRETNA 33.2 32.2 1961
CARMAN 34.0 28.1 1997


GIMLI 32.1 33.1 1989
ISLAND LAKE 29.6 29.7 1989
THOMPSON 27.4 28.7 1989
CHURCHILL 28.2 30.0 1929
FISHER BRANCH 30.5 32.2 2003
WINNIPEG 35.3 36.7 1931

Severe thunderstorm approaching Winnipeg

At 4:30 pm radar displayed a rapidly developing thunderstorm approaching Winnipeg from the southwest. A severe thunderstorm warning has been issued for this cell. Radar indicates possible rotation with this storm which may indicate tornadic potential. Very strong downdraft winds and torrential downpours are likely. This storm has developed right along the cold front which is just approaching Winnipeg as of 4:30 pm.

Another scorcher - but relief on the way

It's another scorcher over the Red River valley, with 1 pm temperatures of 33C in Winnipeg and a humidex of 45C.. the steamiest day of the heat wave so far. But relief is on the way as a cold front approaches from the west. As of 1 pm, the front was just about through Brandon with showers and thunderstorms west of the front. Temperatures drop significantly behind the front with values near 20C near the SK border as of 1 pm. The front should be moving through Winnipeg later this afternoon with noticeably cooler conditions and some rain moving in this evening.

Tuesday, July 24, 2007

Another sultry night.. relief coming Wednesday

We got to 34.8C at Winnipeg airport today, just 0.2C off the record high for today with humidex values peaking at43C. And after today's steamy weather, there won't be much relief tonight. It will be another very warm night across southern MB, especially here in Winnipeg and the Red River valley where gusty southerly winds will persist tonight, keeping temperatures from dropping much. As a result, temperatures will remain above 30 well into the evening, gradually dropping to an overnight low of only 26C. That would be Winnipeg's second warmest low temperature on record, behind only July 12 1936 when a low of 28.3C was recorded. That will mean a very uncomfortable night for sleeping for those without A/C.

Relief however is on the way on Wednesday. A heat-wave ending cold front will be coming through by midday or early afternoon. So after another warm and muggy morning with temperatures peaking at 32C by midday, winds will shift into the northwest in the afternoon sending temperatures and humidex values down. By evening, temperatures will likely be down to the 25C mark, and 20c by midnight with lows of 16C by morning. In addition, the cold front will likely be accompanied by showers and thunderstorms that could bring locally heavy rainfall and possibly some severe winds or hail. Look for more comfortable conditions and seasonably warm temperatures for Thursday into the weekend.

Heat Wave - Day 3

It's already 27C at Winnipeg airport as of 8 am, after an overnight low of only 24C, a record warm night for July 24th (and one of the warmest minimum temperatures on record in Winnipeg). I think we have a good shot at hitting 35C today provided we stay sunny all day. With dewpoints of 23c, that will give peak humidex values of 45 this afternoon, the steamiest day of the heat wave so far.

Tonight will be another warm one.. with a low of only 25C, maybe even 26 or 27C as we get a southerly breeze all night. If so, that will be Winnipeg's second warmest minimum temperature on record (warmest minimum was an amazing low of 28.3C on July 12 1936 following Winnipeg's hottest day ever of 42.2 on July 11) However, that low of 25C will likely not be the minimum for Wednesday. The heat-wave ending cold front will be coming through by midday, so temperatures will be dropping noticeably in the evening, likely below 25C by midnight.

Monday, July 23, 2007

Heat Wave - Day 2

After a sizzling Sunday, it's a meltdown Monday as the hot and humid airmass persists over southern MB. As of 11 am, humidex values had already surpassed the 40 degree mark over many localities thanks to some very high dewpoints today.. including an unbelievable 28C dewpoint reading at Carman. (I suspect this value is erroneously high, as the dewpoint at Carman always seems to be a couple of degrees too moist compared to neighbouring sites.) Nonetheless, dewpoints across southern MB are in the 22-25c range today which will make today's 35C temperatures feel oppressive. Take it easy out there.

By the way, I replaced the barometric graph plot on my main page with a dewpoint/heat index plot to better gauge how sticky it is over the next few days.

Sunday, July 22, 2007

The heat is on!..

It was a sizzling Sunday across southern Manitoba with temperatures of 32 to 33C and humidex values of 40 to 44C. As they say, it wasn't the heat.. it was the humidity, or more accurately, the dewpoints which were in the 21 to 24C range across southern MB. These dewpoints are in the uncomfortable range, and makes it more difficult for the body to cool off by evaporation. (see graph from my weather station showing dewpoint and heat index from today. Notice how the dewpoints dropped late in the day!)

And it looks like the hot humid weather will continue for the next 2 to 3 days before a cold front brings more comfortable conditions by Wednesday evening. Until then, expect more of the same as today with afternoon temperatures of 32 to 35C, and humidex values of 40 to 45C. Stay cool!

By the way, you may notice that my weather station displays "heat index" rather than the humidex. The "Heat Index" as shown on my station is an equivalent temperature based on air temperature and humidity (or more accurately, the dew point). It is similar to but NOT the same as the Canadian "humidex" value, which employs a slightly different equation and gives different results than the American "Heat Index". Generally the Heat index will register about 3-5C lower than the humidex. My station can only display heat index. A simple way of calculating the humidex is to add the temperature and dewpoint (in C) then subtract 13. For example, if the air temperature is 32C and the dewpoint is 22C then the humidex is 41C (32 + 22 - 13 = 41C) Environment Canada issues humidex advisories when humidex values of 40C or greater are expected. Whatever the case, both indeces are designed to tell you how hot it "really" feels based on the moisture content of the airmass. The basis for this is that when it's humid, it becomes harder for the body to cool since evaporation from the skin (i.e sweating) is less efficient. Thus, 30C with 60% humidity will feel "hotter" than 30C with 30% humidity because the body will not be able to cool as quickly at higher humidity levels. In reality, it's not any hotter, it's just more uncomfortable.

The dew point is the best indicator of how humid or "sticky" an airmass is. The following table gives a rough idea of dewpoint and comfort of an airmass..

< 10C ..............dry
10-14C ............comfortable
15-17C ............moderately humid, still comfortable for most people
18-21C ............humid, uncomfortable for most people
22-24C ............very humid, uncomfortable for everyone
>24C ..............oppressive, stifling

In our latitudes, dewpoints above 24C are rare although they do occur sometimes in southern MB in the growing season due to contribution from evapotranspiration from plants and crops. Dewpoints of 27C or more are usually only found in tropical areas near warm oceans.

Wednesday, July 18, 2007

Western heat wave spreading east this weekend

The heat wave that has gripped the western Prairies for the past week with temperatures in the mid to upper thirties will be spreading east over southern Manitoba beginning this weekend. A ridge of high pressure over southern Manitoba on Thursday will move east into the Great Lakes by Friday. A return southerly flow west of the ridge will draw increasingly warm air from the western U.S. and Canada into southern MB over the weekend, with temperatures expected to climb into the low to mid thirties by Sunday. The hot weather is expected to continue through much of next week with temperatures likely persisting in the thirties most of the week. Little precipitation is expected over the period, except for a possibility of some showers or thunderstorms Tuesday and Wednesday as a weak cold front tries to move through southern MB.

Officially, a heat wave is defined as a period of at least 3 consecutive days with maximum temperatures of 32C or greater. This is a throwback from the Fahrenheit days when we used 90F (32C) to define a "hot" day. Unofficially, we have started to define a heat wave in Canada as a period of 3 days or more with maximum temperatures of 30C or more. It's a nice round number, and it's a good threshold for most Canadians to define as a "hot" day. Either way you slice it, it looks like an extended period of hot weather is coming to southern MB!

Tuesday, July 10, 2007

Rainfall Summary


PILOT MOUND............ 57.2 MM
EMERSON................ 52.0 MM
GRETNA................. 50.6 MM
MORDEN................. 45.8 MM
STEINBACH.............. 36.6 MM
CARMAN................. 29.4 MM
SPRAGUE................ 27.0 MM

Whyte Ridge ............. 20.4 MM
Charleswood (Rob's Obs).. 16.5 MM

Saturday, July 07, 2007

Steamy Saturday

Whew.. it's a sweltering one out there today. As of 2 pm, my weather station is showing 29C with a 23C dewpoint giving a humidex of 39C. Very uncomfortable. (A trick to estimate humidex.. add the temperature and dewpoint in C, then subtract 13). Even more oppressive down to our south with Emerson checking in with a 42C humidex as of 2 pm (temp 32C dewpoint 23c) The hot and humid airmass will trigger a few thunderstorms this afternoon as a cold front approaches from the northwest. A few of thes storms may become severe, with large hail and damaging winds being the main threats. Isolated tornadoes are also possible given the extreme instability today. EC has issued a severe thunderstorm watch this afternoon for much of southern Manitoba including Winnipeg. Stay tuned and keep an eye to the sky if you're out and about today.