Sunday, December 21, 2014

Staying mild until Christmas.. then pattern change to colder weather

Today may be the official start of winter, but the unseasonably mild weather of the past two weeks is forecast to continue for the the next few days with temperatures some 10-20C above normal for late December.  Highs today and Monday will be near or slightly above freezing with nighttime lows only around -2C, well above normal highs of -11C and lows of -22C for this time of year.  The weather will continue to be generally cloudy and dull with a chance of freezing drizzle or light flurries from time to time today into Monday. A storm system tracking into the Dakotas Monday into Tuesday will bring some light snow across the Red River valley and SE Manitoba, with a couple cm possible, especially south and east of Winnipeg. Cloudy and slight cooler conditions are expected behind this system for Wednesday into Thursday (Christmas Eve and Christmas Day) although temperatures will continue above normal, with highs near -5C. A storm system tracking though the Dakotas Thursday night into Boxing Day may bring a round of snow to southern Manitoba, but the main story with this system will be the colder air that will follow in its wake. Temperatures are expected to drop to normal or below normal values for Boxing Day and the weekend into next week, with temperatures in the minus 20s and possibly minus 30s again.

Thursday, December 04, 2014

Major warm-up expected across Prairies, much of North America next week..

6-10 day outlook valid Dec 10-14
showing massive warmup over
central North America (CPC)
For those already tired of the mid winter-like cold that has gripped southern MB and the Prairies much of the past 3 weeks, some good news is on the way. A major shift in the weather pattern next week is expected to bring a prolonged period of above normal temperatures across much of the southern Prairies and central North America through next week. We'll get a taste of the milder weather on Sunday as a weather system tracks across southern Manitoba bringing a southerly flow of milder air across the south, with temperatures likely climbing towards the freezing mark in Winnipeg and slightly above freezing over parts of western MB. We'll get into some briefly colder air on Monday behind this system, but the colder weather will be short lived as a massive influx of Pacific air spreads over the Prairies beginning Tuesday. This flow of warmer Pacific air will overspread southern Manitoba by mid to late week, sending temperatures in Winnipeg and the RRV above freezing from at least Thursday into Saturday. In fact, some downslope areas from Dauphin through McCreary to Portage La Prairie, Morden and Winkler may see temperatures of +7-10C by Friday.  That will result in considerable melting of the meager snowpack across southern Manitoba.. with areas of  bare ground likely re-appearing by the end of the week in parts of the RRV and SW Manitoba. So put away the block heater cords for awhile and stock up on the washer fluid.. warmer weather is on the way!

Friday, November 28, 2014

5-10 cm of snow on the way for Winnipeg

24 hr precip amounts in mm to noon Saturday
(add 50% for snowfall amounts in cm) 
Get those shovels ready.. snow is on the way across much of southern Manitoba today into tonight as a storm system over Montana tracks into the Dakotas. Snow from this system has spread into western Manitoba this morning and will continue to spread eastward into Winnipeg and the Red River valley this afternoon. Snow will pick up in intensity by the afternoon rush hour, with 2 cm possible by evening. Snow will continue tonight into Saturday morning with another 5 cm possible in Winnipeg by the time it tapers off by midday Saturday. In total, about 5-10 cm of snow is possible across Winnipeg and the northern RRV, with less to the south of Winnipeg and more to the north. Heaviest snowfall for this system is expected over western MB Parklands and central Interlake regions (Riding Mtns, Dauphin, Arborg, Ashern, etc) where 15-20 cm is forecast by Saturday. In behind this system, winds will shift into the northwest Saturday tapping cold Arctic air once again, with temperatures falling from morning values of -10C towards -20C by Saturday evening. Cold but dry weather is on tap for Sunday and Monday with a moderating trend the rest of the week as the arctic airmass relaxes its grip over southern MB.  

Tuesday, November 25, 2014

Ready or not.. here comes some mid winter cold..

NAM model showing surface temperatures (F)
Wed morning. Arctic high building in from Saskatchewan
will bring in mid winter cold over southern MB  
Uggh. Not the news we want to hear, but the coldest weather of the season will be moving into southern MB over the next couple of days as a mass of Arctic air over the north spills southward. This airmass will be ushered in by a large Arctic ridge of high pressure over northern Saskatchewan that will build southward into southern Manitoba overnight into Wednesday bringing temperatures more typical of mid January than late November.

For tonight, a weak clipper system that has been bringing some light snow across southern MB today will exit the province, with gradually clearing skies tonight from the north. This will allow temperatures to drop well into the minus 20s by Wednesday morning, with some spots in the northern Interlake likely hitting the -30C mark (Moosehorn, Grand Rapids, Berens River, Swan River, etc)  In Winnipeg, temperatures are forecast to drop to -26C overnight with light northwest winds creating wind chills near -35 for the morning commute. Temperatures will recover only to around -18C Wednesday under sunny skies, some 13C below normal for late November. Wednesday night into early Thursday will be downright frigid in Winnipeg and the RRV as the core of Arctic ridge crosses the region. That will allow temperatures to plummet towards the -30C mark even in Winnipeg Wednesday night into early Thursday morning.. so make sure you have those block heater cords ready and working! (For the record, the earliest that Winnipeg has hit -30C or lower was on November 19th in 1896 with a reading of -33.9C. Record low for Thursday (Nov 27th) in Winnipeg is -36.1C in 1891, and more recently in Nov 1985, the airport had 5 days of -30C or lower over the last week of November. So believe it or not, it has been worse at this time of year)

A slight moderation is expected by Friday as the next clipper system moves in with some light snow, and high temperatures near minus 10C. Unfortunately, it looks like we're back into the deep freeze over the weekend into early next week behind the clipper system. There are some signs that the abnormally cold pattern will relax a bit by the middle to end of next week, but we'll have to see if those moderating signs continue over the next few days. Until then, bundle up and get prepared for some mid winter cold.. in November!

Friday, November 21, 2014

Mild weekend ahead.. but turning snowy and colder Sunday night. Tricky Monday morning commute likely..

After 2 weeks of well below normal temperatures, southern MB will be getting a brief break this weekend with some milder temperatures as a couple of weather systems track across the central Prairies drawing milder air across the south.  Southwest winds ahead of the first system today have pushed temperatures well above freezing over snow-free SW Manitoba with Brandon up to +7C this afternoon and +9C in Pierson. A brisk southerly wind over the snow covered Red River valley was keeping temperatures slightly colder in Winnipeg at -2C this afternoon.  For Saturday, a weak ridge of high pressure will cross southern MB giving dry weather and light winds, with temperatures above freezing. By Sunday, a storm system will track across southern MB bringing snow through the Interlake and western MB parklands with 10-15 cm possible by Sunday night. As this system tracks east of the RRV later Sunday, winds will shift into the north and draw colder air into Winnipeg and the Red River valley with snow developing. Snow will continue Sunday night into early Monday along with gusty north winds producing local blowing and drifting snow. It's possible we may see 5-10 cm of snow by the Monday morning commute in Winnipeg although there is still considerable uncertainty on snowfall amounts at this point. Regardless, residents should plan for a slow commute to work or school Monday morning due to sharply colder temperatures, gusty north winds giving local blowing and drifting snow, and slippery road conditions.

Friday, November 14, 2014

Manitoba lakes freezing up quickly

MODIS satellite image of MB lakes
Saturday Nov 8 2014
MODIS satellite image of MB lakes
Thursday Nov 13 2014

Well below freezing temperatures over the past week has brought the first snows of the season over much of southern MB as well as a rapid freeze up of the Manitoba lakes. The two "false colour" MODIS satellite images above were taken just five days apart between Nov 8th (left) and Nov 13th (right)  The images show a much different landscape over southern MB over that time with more extensive snow cover (shown in light blue) and a rapid freeze up of the western MB lakes, with Lake Manitoba and Lake Winnipegosis now mainly ice covered. Lake Winnipeg still remains generally ice free except along the shores and some bays.. which is allowing lake effect cloud and flurries to persist as cold winds blow over the open water (open water seen as dark blue on satellite imagery with clouds seen in white)  In fact, you can see the bands of heavier lake effect snow over the past day or two immediately south of Lake Winnipeg and Lake Manitoba, with less snow cover elsewhere over southern MB (bare land shows up as light brown) 

With a continuation of well below freezing weather over the next 5 to 10 days, ice cover will continue to grow rapidly on the lakes, with Lake Winnipeg likely freezing up by the middle to end of next week. This will effectively shut off the lake effect machine for the season, and will also allow invasions of cold air to spread into southern Manitoba unmoderated by the lakes. Like it or not, winter is here folks! 

Tuesday, November 11, 2014

Lake enhanced snowbands may make for tricky morning commute

Snowfall warning issued
for areas south of MB lakes
A cold northerly flow of Arctic air moving over the open waters of Lakes Winnipeg and Manitoba will set the stage for the development of lake effect snowbands this evening which will likely persist tonight into Wednesday. The north to south snow bands will be quite narrow and localized, but could be fairly intense with local snowfall accumulations of 10-15 cm possible within these bands tonight into Wednesday.  Off Lake Winnipeg, the main snowband is expected to set up through Selkirk and eastern Winnipeg into the Niverville area although the band may drift from time to time and fluctuate in intensity. Off Lake Manitoba, a lake effect snowband is expected to set up through Portage La Prairie to just west of Carman to the Morden area. In between these snowbands, occasional light snow or flurries are expected tonight into Wednesday morning with 2-5 cm possible. This will likely make for a slower commute Wednesday morning especially under the heavier snowbands which could be affecting east Winnipeg early Wednesday. A snowfall warning is in effect for areas immediately north, east and west of Winnipeg due to these expected heavier snowbands.

Thursday, November 06, 2014

Mild pattern coming to an end.. colder weather on the way this weekend through next week

6-10 day CPC outlook for next week shows
massive outbreak of below normal temps
over central and eastern NA

The extended period of mild weather we've been enjoying across southern Manitoba over the past month will be coming to an end this weekend as a large scale change in the upper weather pattern drives cold Arctic air southward over the next week or two. The change in the weather pattern will be heralded by a storm system tracking across Manitoba tonight into Friday that will bring some rain across the south along with increasing winds and one final shot of milder temperatures. As the system pushes east into Ontario, it will drag a cold front across southern Manitoba Friday afternoon with winds shifting into the northwest. These winds will bring in colder air Friday night into the weekend with temperatures remaining below freezing. Fortunately, it looks like the cold weather won't be accompanied by a lot of snow, although there will likely be bands of lake effect snow off the Manitoba lakes at times, as well as occasional flurries over southern MB. The cold weather pattern is expected  to persist through next week with generally dry conditions and perhaps an occasional dusting of snow with weak impulses passing through from time to time. Currently, no major storm systems are forecast to impact southern Manitoba over the next week which would minimize the chances of a significant snowfall. However, with this prolonged change to cold weather, it will only be a matter of time before a system brings the first widespread snows across southern Manitoba. Until then, bundle up!   

Monday, October 20, 2014

Nice fall weather this week

Temperatures will be running well above normal this week over southern Manitoba as an upper ridge of high pressure builds over the eastern Prairies. Sunny skies and gusty south winds Tuesday will send temperatures into the mid to upper teens, with lows 20s likely across SW Manitoba.  On Wednesday, clouds will increase ahead of a weak system crossing southern Manitoba that may trigger some scattered showers by afternoon or evening. Temperatures however will remain mild in the mid to upper teens. Sunshine will return for Thursday and Friday with temperature again in the mid to upper teens, some 10C above normal for late October.  Slightly cooler conditions are expected early next week, although there are no indications at this point of a change to a prolonged below normal temperature pattern through the end of October.     

Thursday, October 02, 2014

Big change in the weather pattern Friday into the weekend.. strong winds, colder temperatures and possible snow..

Wind and wave impact maps for south basins
of Lakes Winnipeg (right) and Manitoba (left)
Severe impacts are possible Friday Oct 3rd
along south shorelines (in red)
(image from province of Manitoba)
It was a pleasant Thursday over the Red River valley with mainly sunny skies and afternoon temperatures up to 19C. But a major change in the weather is arriving tonight in the form of a strong cold front that is pushing across western MB late this afternoon. Showers and even some isolated thunderstorms will accompany this front this evening, followed by a northwest flow of much cooler air tonight into Friday. Friday will be a much colder day, with temperatures some 10-13C colder than today along with occasional rain or drizzle and strong northwest winds gusting to 70 km/h. The rain may even mix with some wet snow over higher elevations of the western RRV Friday. Northwest winds will be especially strong over Lake Manitoba and Lake Winnipeg overnight into Friday morning with gusts to 80 km/h at times. The province of Manitoba has a issued a severe wind alert for Lake Winnipeg and Lake Manitoba warning that strong northerly winds and significant wave action may cause lake levels to rise up to 5 feet over the south basins. Note that lake levels are higher than normal due to excessive summer rainfall, especially over western MB. Lake Manitoba is at 814.2 feet while Lake Winnipeg is at 715.6 feet above sea level. The higher than normal lake levels together with strong wave and lake seiche action will lead to shoreline erosion concerns particularly along the southern and eastern shores of the lakes.

Video:  See video footage of waves at Twin Lakes on southeast shore of Lake Manitoba Friday. (from CBC)

Snowy scene Friday afternoon near Lake Brereton, MB
in the Whiteshell Park area, just one week
after experiencing 30C temperatures 
As the main precipitation shield from this system pulls away Friday, narrow bands of lake effect showers will develop over and to the south-southeast of the MB lakes. In fact, it's possible these lake effect showers may change over to snow inland from the lakes as temperatures drop Friday night into early Saturday, with the potential for accumulating snow in some narrow bands southeast of the lakes. Cold and blustery conditions will persist through the weekend with temperatures some 5-10C below normal for early October.

Thursday, September 25, 2014

Record blast of late season heat over southwest Manitoba

4 pm temperatures across RRV and SW MB - Sep 25 2014
Temperatures soared into the 30s over SW MB
A sprawling upper ridge of high pressure over central North America together with a southerly flow of unseasonably warm air from the southwestern United States resulted in a late season blast of summer like temperatures over southern MB today, especially over southwestern parts of the province. Temperatures soared into the upper 20s over the Red River valley, and into the low to mid 30s over southwest Manitoba. These temperatures were some 13 to 18C above normal for late September, and resulted in some impressive late season heat records. In Brandon for example, the high of 34.0C at YBR airport was not only a record for the day (prev record 31.1C in 1950), but was also the latest the city has hit a temperature over 33C (previous latest was on Sept 22 1938 with a high of 33.9C)   It was even warmer southeast of Brandon with a high of 35C in Wawanesa from the Manitoba Ag weather network.  South of the border, WiIlliston ND hit an incredible 36.1C (97F), easily a record for the day and the latest the city has ever been that hot.

Record highs across the central Prairies Sep 25 2014
(Graphic from The Weather Network)
In Winnipeg, temperatures weren't quite as high as areas further west, but it did manage to reach a high of 27.7C at Winnipeg airport.. the warmest day of the month so far and about 13C above normal. The day was accompanied by brisk southerly winds and abnormally high dewpoints for late September.. with a dewpoint reading of 18C by the afternoon and evening. This was the highest dewpoint ever recorded for Sept 25th and is one of the latest days in the year for dewpoints of 18C or more (latest is Oct 11 1997 with a dewpoint of 18.1C)

Friday should be a repeat day over southern MB, with temperatures in the upper 20s and low 30s once again along with sunny skies and humid conditions (dewpoints again in the upper teens) Southerly winds however will be stronger Friday in Winnipeg and up the RRV, with gusts to 60 km/h or more. Temperatures should climb to a high of 28-29C in Winnipeg, just shy of the record high for Sept 26th of 31.7C set in 1952. Saturday will see one more warm day over the Red River valley with highs in the mid 20s, before a cold front pushes through by afternoon.  This front will usher in much cooler air by Sunday with highs only in the low teens along with periods of rain. So enjoy these last couple of summer like days before reality kicks back in!

UPDATE: Fri Sept 26:  It was another unseasonably warm day across southern Manitoba with temperatures climbing to the 30C mark or higher in most areas.  Winnipeg hit a high of 30.2C, some 15C above normal for Sep 26th, and just 1.5C shy of the record high for the day. In addition, humidity values were unusually high for late September with dewpoints of 18C through midday, resulting in a peak humidex reading of 36C by late afternoon, the latest in the season that Winnipeg has hit a 35C+ humidex since humidex records began in 1953 (previous latest on record was a 38C humidex on Sep 19 2004). The hot spot in the province and country today was Swan River at a sizzling 35.1C.

Sunday, September 21, 2014

Fabulous first week of fall ahead!

Great harvesting weather is expected this week
across southern MB with dry and warm conditions
(photo by Shawn Dziuk near Glen Ullin, ND) 
After a gloomy and occasionally damp weekend, the weather pattern will be turning decidedly warmer and drier across southern Manitoba this week as an upper ridge of high pressure builds across the Prairies. The result will be a fabulous stretch of dry and warmer than normal weather over the upcoming week with temperatures climbing into the mid 20s at times, and possibly even upper 20s by late week. This will be welcome news for farmers trying to harvest this year's crop, and just in general for any outdoor activities. Fall officially arrives Monday evening (Sept 22nd), but fall-like weather will be delayed for awhile as we get a nice last taste of summer-like weather this week. Officially, Winnipeg has yet to record its freeze of the season yet, with a minimum temperature so far this month of +1.1C at YWG airport (Sept 12th) On average, Winnipeg usually records its first freeze of the season by Sept 22nd, so the growing season will be extended a bit longer than normal this year. After this past winter's bitter cold and slow start to spring, we deserve it! Enjoy!

Sunday, September 14, 2014

Warming trend this week

After an early taste of fall like weather, temperatures will be returning to more normal values this week over southern Manitoba as a large cool airmass pushes east out of the Prairies. In its place, a moderating trend will become established over much of the Prairies as a zonal upper flow develops, allowing milder air from western Canada to spread east across the Prairies into southern Manitoba. This will allow temperatures to climb into the upper teens over the next few days and lower 20s later this week, which is near or even a bit above normal for this time of year (normal high for Winnipeg is now 18C)  High temperatures Wednesday may dip into the mid teens as we get sideswiped by a cold front pushing through the Interlake into NW Ontario, but then temperatures should rebound quickly for late week into the weekend and next week.  In addition, the weather should remain generally dry this week over southern Manitoba until Friday when a system will bring the next main threat of showers. The upcoming warmer and drier weather pattern will be most welcome by farmers looking to ramp up harvesting activities after an unsettled first week and cool second week of September.  

Saturday, September 06, 2014

Enjoy the summerlike weekend.. an early blast of fall coming by Tuesday

Say goodbye to summer this week!
850 mb temperature map shows blast of cold air
flooding across the Prairies by late Monday
It was a lovely Saturday over southern Manitoba as afternoon sunshine and southwest winds pushed temperatures well into the 20s across the RRV, including a high of 25.3C in Winnipeg, about 5C above normal for this time of year. Sunday looks just as nice with sunshine and light southerly breezes pushing afternoon temperatures back to the 25C mark again.. perfect weather to enjoy the Broadway ManyFest street festival, the annual Bombers-Riders Banjo Bowl game, or any other late summer outdoor activities. Enjoy it while you can because there are BIG changes coming in the weather this week across the Prairies. An unseasonably cold airmass will be barreling down from the Arctic early this week, bringing a blast of well below normal temperatures from Alberta to Manitoba. This colder airmass will be ushered in by a cold front pushing across southern Manitoba late Monday into Monday evening. Temperatures in the 20s Monday afternoon will plummet Monday night, with temperatures on Tuesday struggling in the 10-13C range along with cloudy skies and brisk north winds, making it feel more like October than September. The cold weather will persist the rest of the week with cloudy skies, patchy light rain or drizzle, and temperatures only in the single digits to around 10C.  That's a good 10C below normal for this time of year.  If that wasn't bad enough, higher elevations of western MB (such as the Riding and Duck Mtns, Turtle Mtn, etc) may even see the season's first flakes of .. *gasp*.. SNOW by mid week! (Very early, but not unprecedented for those higher elevations) The saving grace is that clouds and wind may prevent a widespread killing frost during the week for the remainder of southern Manitoba, but if there are any areas that clear at night, frost will be a major concern during mid to late week. So enjoy the summerlike Sunday.. a taste (or more like a heaping serving) of fall is on the way!

Wednesday, September 03, 2014

Another round of rain..

WPC 24hr rainfall forecast (in inches)
valid Wed to Thur evening
Another storm system is forecast to track across the Dakotas tonight and across SE Manitoba Thursday bringing another round of wet and possibly stormy weather to southern MB. Scattered showers and thunderstorms in advance of the system will push across southern Manitoba this evening and tonight before a steadier area of rain pushes across western MB through the Interlake overnight through Thursday. Locally heavy rainfall is possible within this band, with amounts of 25 to 50 mm possible in some areas by Thursday evening. Heaviest rainfall is expected in southeast SK where up to 70 mm of rain is forecast by Thursday evening. Here in Winnipeg and the RRV, lesser amounts of rain are expected.. on the order of 10-20 mm, however locally heavy downpours are possible with any thunderstorms that track though tonight especially near the US border.   Rain will taper off Thursday evening across the Winnipeg area with clearing skies by Friday. Note also that strong northerly winds gusting to 70 km/h or more are expected behind this system by Thursday evening which may cause shoreline problems on southern ends of Lake Manitoba and Winnipeg Thursday night due to high water levels.  Sunny and seasonable weather is expected Friday into the weekend with a warming trend for Sunday and Monday as temperatures rise towards the mid 20s again. Unfortunately, the warmup looks short lived as another system tracks through Tuesday with more showers, and a change to much cooler weather for mid to late week next week. In fact, it's possible southern MB may be seeing its first frosts of the season by the end of next week.  

Sunday, August 31, 2014

Soggy end to wet but warm August..

It was a wet finish to the month of August over Winnipeg and the Red River valley as another weather system brought widespread rain to southern Manitoba today. In general about 15-25 mm of rain fell in most areas, with 20 to 40 mm over parts of the southern RRV and southwest MB.  In Winnipeg, the official rainfall at the airport today was 18 mm, with 17 mm falling at the Forks. At my location in Charleswood, I picked up 21.6 mm today bringing my monthly total to 137 mm.. well above the August average of 77 mm. The bulk of this month's rain has fallen over the past 2 weeks, with a couple of significant rainfalls across the city including August 21st when a slow moving thunderstorm complex dumped 50-100 mm over the southwest to central parts of the city. Officially, the airport recorded 104 mm this month, while the Forks had 133 mm with amounts over 170 mm from the Tuxedo to Linden Woods area. 

The wet finish to the month was in sharp contrast to a dry July and first half of August which saw below normal precipitation in Winnipeg.  Temperature-wise, August will finish with an average temperature around 19.3C at YWG airport.. slightly above the average August temperature of 18.8C.        

Saturday, August 23, 2014

Areas of heavy rain tonight into Sunday morning.. severe thunderstorm risk Sunday afternoon/evening

WPC 48 hr rainfall forecast (inches) through Monday
70-80 mm noted through Interlake and western MB
with 30-50 mm over the RRV including Winnipeg  
It's going to be an interesting 24 hours coming up over southern MB as a strong low pressure system over the western Dakotas tracks into southwest Manitoba Sunday. Showers will spread into southern MB this evening ahead of a warm front associated with the storm system, with heavier showers and thunderstorms likely overnight into Sunday morning as increasingly moist conditions spread north. Some of the rainfall could be quite heavy tonight into Sunday, with amounts of 25 to 50 mm possible across much of the Red River valley by Sunday morning. Rainfall rates may be torrential at times, which could cause local flash flooding especially in urban areas. Showers and scattered thunderstorms will settle across the Interlake and western MB Sunday giving widespread soaking rains in those areas, with local amounts of 50 to 75 mm possible by Sunday night. Further south, showers and thunderstorms will move out of the RRV Sunday morning, with a southerly flow bringing warmer and more humid conditions by the afternoon. An approaching cold front however will set the stage for scattered thunderstorms to develop over the RRV and SE MB Sunday afternoon into the evening.. with a risk of locally severe thunderstorms if there's enough sunshine that breaks through in the warm sector. (See local stormchaser Dave Carlsen's blog entry on Sunday's severe thunderstorm potential) Much cooler conditions will follow in the wake of this cold front Monday and Tuesday with high temperatures only in the teens. All in all, an active period of weather coming up over the next 24 hours!

EC Summary of rainfall amounts over weekend

Friday, August 22, 2014

Torrential rains swamp Winnipeg

6 pm radar shows nearly stationary
thunderstorm complex over SW
Winnipeg into downtown core
After an extended period of warm and humid weather, Mother Nature unleashed over Winnipeg late Thursday afternoon with a nearly stationary thunderstorm complex that swamped much of the central and southern parts of the city. Thunderstorm cells started developing near the city around 5 pm.. and by 530 pm, a nearly stationary band of heavy thunderstorms had set up from the southwest part of the city into the downtown core.  Over the next 90 minutes, some 50 to 80 mm of rain /a month's worth of rain/ would fall across this swath, resulting in extensive flooded roads and underpasses, as well as flooded buildings (including Polo Park mall).  The rush hour deluge led to traffic chaos with several main streets in and out of downtown restricted or blocked due to floodwaters. City officials are describing the event as a 1 in a 100 year storm based on rainfall intensity. ( More photos and stories on the flooding from Winnipeg Free Press and Winnipeg Sun. )

In one of the more popular images from Thursday's deluge,
a resident snorkels in floodwaters in Whyte Ridge
(SW Winnipeg) where 80 mm of rain fell in 90 minutes.
Flooded underpass at Higgins Ave.. one of several
underpasses that were flooded in Thursday's deluge
For some, a canoe offered a better mode of
transportation on flooded city streets

Select rainfall amounts from Thursday's deluge..  (unofficial)
Rainfall amounts over south Winnipeg from
WeatherFarm mesonet

Whyte Ridge ............ 81 mm
U of Winnipeg .......... 65-75 mm
Tuxedo .................... 70 mm
Waverly South ......... 70 mm
Grant Park ............... 65 mm
Linden Woods ......... 56 mm
Forks (EC) .............. 53 mm
Charleswood ............ 41 mm
St Vital ....................  25 mm
Winnipeg airport ....... 19 mm
Transcona ..............    5 mm

This was the second time this week that the Tuxedo to Linden Woods area has been hit with heavy rainfall. On Monday afternoon, a narrow band of heavy showers and thunderstorms dumped 35 to 50 mm along this swath. Tuxedo Park school recorded 49 mm Monday with another 70 mm Thursday, for a total of 119 mm within 4 days. Linden Woods has recorded 109 mm since Monday. Normal August rainfall is 77 mm in Winnipeg.

City of Winnipeg rainfall - Aug 21 2014 (between 4 and 10 pm)

The following is a map from the city of Winnipeg showing the distribution of rainfall in the city from Thursday's rainstorm. One can see the heaviest rain axis stretching from the southwest Perimeter into the downtown core up towards North Kildonan. The maximum was in the Whyte Ridge area which saw over 80 mm of rain between 530 and 730 pm. (NOTE: The Fort Whyte station recorded an erroneously low number on this map due to a plugged gauge) The city has a network of over two dozen rain gauges scattered throughout Winnipeg to monitor rainfall within the city, which can vary widely in short distances during convective storms (which is the primary mechanism for precipitation in the summer months here)  This network of stations helps give the city a much more detailed picture of rainfall distribution within Winnipeg, compared to only 2 official Env Canada sites in the city (Winnipeg airport and The Forks)  Link to City of Winnipeg rainfall map.

Monday, July 14, 2014

Nice warming trend this week.. risk of thunderstorms over weekend

CPC 6-10 day outlook valid
Jul 20-24 indicates return of
warmer air over southern MB 
After a record cool Sunday (max of only 15.7C), temperatures will be on an upswing this week as a deep vortex over Ontario shifts east and weakens. This will allow warm air over western and northern Canada to spread east into southern Manitoba over the next few days, along with plenty of sunshine. Temperatures will climb to 23C Tuesday and reach seasonable highs of 26C by Wednesday.  The heat will return for the end of the week with temperatures expected to hit the 30C mark Thursday and Friday. Things get a little more uncertain for the weekend, with models hinting at some showers or thunderstorms by Sunday with increased humidity. After that, indications are that temperatures will climb above normal again for early next week. All in all, looks like a nice taste of summer coming up after a brief flirt with fall Sunday!

Wednesday, July 09, 2014

Seasonably warm weather ahead.. but another cool outbreak Sunday into early next week as heat wave builds over BC

Looking for heat over the next week?
Head west!
CPC 6-10 day outlook looks cool
for southern MB/Ontario.
Pleasant summerlike weather is in store for southern Manitoba over the next few days as a ridge of high pressure over Manitoba gradually pushes east into NW Ontario. Temperatures will climb to about 24C today and into the upper 20s Thursday, before a weak cool front pushes through Thursday night bringing a threat of showers and thunderstorms across the RRV into early Friday. Pleasant weather is expected Friday and Saturday with generally sunny skies and temperatures in the mid 20s. Unfortunately, a cold front pushing in from the north will bring a threat of showers Sunday along with a northerly push of cooler air that will likely result in high temperatures of only 18-20C for Monday and Tuesday... well below the normal high of 26C for this time of year. This northerly flow will be the result of a massive upper ridge building over western Canada early next week that will bring an extended heat wave over BC, with temperatures in the 35-40C range in the Okanagan and Fraser Valleys. A gradual moderating trend is expected over southern Manitoba by the middle to end of next week.. but as of yet, there are no indications of a pattern change to hot dry weather over us in the near future.      

Tuesday, July 01, 2014

June 2014: A "normal" month temperature wise.. but much wetter than usual..

June 2014 - Winnipeg Airport
Daily temperature graph and
anomaly from normal
June 2014 in Winnipeg finished with an average temperature of 17.0C, right on average for June based on the 30 year normal.  The statistic is a bit surprising given the frequent cool and rainy spells that occurred, especially in the latter half of the month. However, there were enough warm days and mild nights to boost the monthly average to "normal" values.

Rainfall was a different story. A total of 147.1 mm fell at YWG airport during June, some 57 mm (63%) above the 30 year June average of 90 mm. According to JJ's Winnipeg weather blog, this makes this June the wettest June in Winnipeg since 2000 (177 mm) and the city's 12th wettest June since records began in 1872. Totals were even higher in other parts of the city with 167 mm at my location in SW Winnipeg, and 170 mm at  the Forks downtown. It also didn't help matters that much of the rain fell over the last 3 weekends of the month, spoiling summer weekend plans for many. The rain however was even worse over western Manitoba which was deluged with record rainfall during June. In Brandon, their June rainfall total of 251.6 mm was the wettest month on record since records began in 1890. Previous wettest month was August 1980 at 217 mm. The bulk of the rain fell over the last two weeks of the month, leading to widespread overland flooding over southwest Manitoba. Rivers and lakes are at very high to record high levels across southern Manitoba, with flood warnings and high water advisories on many lakes and tributaries.  The abnormally wet conditions prompted the opening of the Red River floodway on July 1st to ease the risk of flooding in the city of Winnipeg.

So is there any hope of drier weather the rest of the summer?  Too hard to say. The next few days look promising with drier weather for the balance of the week. Increasing heat and humidity over the weekend will lead to a greater chance of showers and thunderstorms developing over southern Manitoba, but hopefully the activity will be more scattered and transitory compared to the past few episodes. Beyond that, there are no clear signals as to how the rest of the summer will shape up. Certainly there's a lot of moisture around which helps to fuel more shower and thunderstorm activity. But a favourable upper pattern can shut off the taps for long stretches as well. We're approaching the peak of summer now (mid July is our summer peak in terms of average temperature), and hopefully Mother Nature starts to take a much-needed summer break soon!

Tuesday, June 24, 2014

Another unsettled weekend ahead.. showers and thunderstorms likely, locally heavy at times

Another weekend, another shot of unsettled weather coming up for southern Manitoba as a warmer and more humid airmass spreads over the eastern Prairies, while periodic weather systems trigger showers and thunderstorms Friday through Sunday. Much like last weekend, this upcoming weekend won't be a total washout with sunny, dry stretches at times. However, occasional showers and thunderstorms are likely each day, especially at night with the potential for some severe thunderstorms.. along with locally heavy rainfall. This will not be welcome news for those hoping to dry out from the wet weather over the past couple of weeks which has produced over a month's worth of rain in Winnipeg within a week. Cooler weather is expected to move in next week behind this unsettled weather pattern. 

Thursday, June 12, 2014

Unsettled weekend ahead.. wet Sunday likely for Dads and runners..

After some dry and pleasant weather this week, it looks like things will be getting more unsettled this weekend over Winnipeg and the Red River valley as a pair of weather systems affect the region. The first wave of precipitation is expected to move in Friday night into Saturday morning ahead of a warm front pushing up from North Dakota, possibly giving 5-10 mm to Winnipeg by Saturday afternoon (although some models are showing much less.. only a couple mm with the first wave). We'll get a bit of a break Saturday afternoon before another wave of rain moves in Saturday night into Sunday as a more potent system intensifies over northern Minnesota. That will likely bring steadier and heavier rain for Father’s Day (and the Manitoba Marathon) with 15-25 mm possible for Winnipeg. Not the best timing on the weekend, but the rain will be beneficial for farmers in the Red River valley, and most marathon runners would rather run in the rain than in the heat. Rain is expected to taper off later Sunday into Sunday night as the system pulls east.

Sunday, June 01, 2014

Warm finish to May salvages slow start to spring..

Temperature departure from normal
for last week of May shows core of warmth
over northern Plains/southern MB (finally!)   
After a dreadfully long cold winter and slow start to spring, persistent warm weather finally returned to southern Manitoba for the end of May, with temperatures some 5-10C above normal over the last week of the month. The pattern change to warm weather was long overdue and finally signalled a break in the below normal temperature pattern that had persisted since last fall. Thanks to the late month warmth, the month finished with an average temperature of 11.3C, just 0.3C shy of normal for May (1981-2010 average of 11.6C)

The warm weather included the season's first 30C weather in Winnipeg, with highs of 33.3C on May 24th (record high) and 32.7C on May 29th. . These marked the hottest May days in Winnipeg since 1995 and the first time since 1995 that we've seen two or more 30C days in May. Amazingly, this hot weather came only 10 days after a trace of snow was recorded on the 14th, the only snow of the month. Rainfall for the month was only 42 mm at YWG airport.. about 75% of the normal May rainfall of 54 mm. All in all, a summer like end to May, much appreciated by long suffering residents of southern Manitoba!

For more details on May statistics, see JJ's Winnipeg Weather blog May summary.      

Friday, May 23, 2014

The heat is on! 30+C temperatures Saturday.. record highs possible

It's been a long wait, but summer like heat is finally back in southern Manitoba as a warm southerly flow draws up above normal temperatures over the province.  Under mainly sunny skies today, Winnipeg airport climbed to 29.6C, the warmest temperature here since last September 6th when it hit 33.6C. And tomorrow is looking even warmer as the peak of this warm airmass moves over southern Manitoba. Temperatures Saturday are expected to hit the 30C mark in Winnipeg and much of southern Manitoba, with values as high as 33C possible in some areas. If we do hit 30C, it will mark the first 30C day recorded in May in Winnipeg since May 2007 (31.3C on May 9th)  Some record high temperatures are likely Saturday in southern Manitoba, including Winnipeg which will challenge the record high of 32.7C for May 24th set in 1980. By Saturday afternoon and evening, a band of thunderstorms is expected to fire up over western Manitoba along a weak cold front which will push into the Interlake and northern RRV areas by evening. Locally heavy downpours, strong wind gusts and hail will be possible with some stronger storms before weakening Saturday night. Unsettled weather with scattered showers or thunderstorms are expected Sunday over Winnipeg and the Red River valley as the weak front slowly advances east.     

Wednesday, May 14, 2014

Warming trend into holiday weekend..

The week is off to a chilly start over southern Manitoba with single digit temperatures and even some snowflurries in Winnipeg early this morning. Skies are expected to clear off overnight allowing for sub-freezing temperatures by Thursday morning. Thursday should be a much nicer day with sunshine, light winds and afternoon highs around 11-12C.. still well below normal for this time of year (normal highs now are near 20C), but much better than today's brisk single digit temperatures. Tomorrow will signal the beginning of a warming trend that will take us into the Victoria Day holiday weekend with temperatures climbing to the 20C mark by Sunday along with partly to mostly sunny skies. Unfortunately, it looks like wet weather will be moving in for holiday Monday with showers and temperatures in the mid teens.

Monday, May 05, 2014

Unsettled week ahead..

The weather this week will become increasingly unsettled as a series of disturbances track across southern Manitoba. The first system will be spreading an area of rain or showers into southern Manitoba Tuesday, first across western Manitoba reaching Winnipeg and the Red River valley by midday or afternoon. Rainfall amounts are not expected to be heavy across Winnipeg/RRV with about 5-10 mm possible through Tuesday night.. although heavier amounts of 15-25 mm are expected over parts of western Manitoba. Another disturbance is expected to bring a second round of showers across southern Manitoba later Wednesday into Wednesday night, with another 5-15 mm possible. Drier weather is expected Friday and Saturday, with near normal temperatures in the mid to upper teens possible. Unfortunately, it looks like another system will bring in wet weather for Mother's Day Sunday. All in all, a somewhat unsettled week ahead..  with temperatures trending towards normal by late week.

Wednesday, April 30, 2014

April ends on cool damp note as below normal streak continues..

Same story.. different month
Below normal temperatures dominated
in April, much like March and February
A cool damp day over Winnipeg and southeast Manitoba marked an appropriate end to the month of April, which will end up as the 7th straight month below normal in Winnipeg. The month will finish with an average temperature of +0.3C, over 4C below normal for April (1981-2010 normal April average of +4.4C), making this the 19th coldest April on record since 1872, tied with the Aprils of 1962, 1888, and 1877.  This follows the 19th coldest March and 21st coldest February, so we've had top 20 type cold weather for 3 straight months now. And it doesn't look like the weather pattern will be changing anytime soon as a persistent upper trough over central North America maintains cooler than normal weather over southern Manitoba through the first week of May at least. Normal highs for Winnipeg are now 16C and will climb to 19C by mid May and 22C by the end of May. If we can even get back to a normal weather pattern by mid May, we would be seeing more frequent and persistent 20C weather. Winnipeg has yet to hit the 20C mark this year, and has hit the 15C mark only once with a high of 15.1C on April 23rd. But there have been worse starts to May.. such as 1979 which saw single digit highs for the first 11 days of the month along with snowflurries almost each day, and a 7 cm snowfall on May 10-11th. Whatever the case, residents of southern Manitoba are eager for a pattern change.. which hopefully comes by the beginning of summer.

Latest dates that Winnipeg first reached 20C (data since 1872) 

1.   May 25 1907
2.   May 21 1956
3.   May 18 1996
4t.  May 17 1935, 1967
6t.  May 16 1883, 1892, 1979
9.   May 15 1884
10. May 14 1902

Source: Environment Canada

Saturday, April 26, 2014

Another round of wet weather moving into southern Manitoba Sunday night through Monday

RDPS model valid midday
Monday Apr 28th
showing widespread precip
from US storm system
After a brief break this weekend, another round of wet weather will be moving into southern Manitoba Sunday night into Monday as a large storm system south of the border spreads widespread rains northward. Rain from this system will be pushing into the southern RRV and SW Manitoba by late Sunday into Sunday evening, reaching Winnipeg during Sunday night. Rain will continue through Monday before tapering off Monday night. Rainfall totals of 15-25 mm will be widespread across southern Manitoba with amounts of 30 to 40 mm possible over portions of the southern and western RRV into southwest Manitoba. In addition, precipitation could even be mixed with wet snow over western Manitoba Sunday night into Monday morning with slushy accumulations possible over higher elevations. Drier but cool weather is forecast through mid week with temperatures running some 5-10C below normal for the end of April. Unfortunately, there are still no signs of a major pattern change to above normal weather for us into early May.

Monday, April 21, 2014

Wet weather moving in for mid week..

More typical springlike weather has finally become established across southern Manitoba as the winter snowpack has pretty much disappeared across most areas. This is allowing the late April sun to warm up the surface more easily, with temperatures reaching more seasonable values now.  Tuesday looks to be a beautiful day with lots of sunshine and temperatures reaching the mid teens.. pretty much normal for this time of year. The nice weather however will be short lived as a large storm system developing over the western Prairies brings a widespread area of rain across southern Manitoba during Wednesday, reaching Winnipeg by late afternoon or evening. Rain will become steadier and heavier Wednesday night, with a good soaking of 15 to 25 mm possible through Thursday, likely our most significant rainfall since last October. Rain will taper off Thursday night, possibly changing to some wet snowflurries by early Friday as colder air works in behind the system. Cooler than normal weather will follow in the wake of this system through the weekend into early next week. This will ensure that April finishes below normal by a good 4-5C, the 7th straight month that has ended up below normal in Winnipeg. The last month that was above normal here was last September which finished 2.5C above normal. Hopefully, May can finally break the below normal streak..    

Sunday, April 13, 2014

Record cold possible this week before warming trend for Easter holiday weekend..

Well below normal temperatures will once again flood into southern Manitoba over the next few days in the wake of yesterday's storm system that brought snow, ice pellets and patchy rain or drizzle across the area. Temperatures are expected to remain below freezing through Thursday before milder weather moves in by the end of the week. Temperatures for the first half of the week will be more typical for early March than mid April, with highs around -5C and lows near -15C, well below normal for this time of year (normal highs are now +10C, normal lows -2C)  In fact, some record low maximum and minimum temperatures will be challenged this week in Winnipeg, especially Tuesday and Wednesday.

Record temperatures for Winnipeg this week.

DATE.........    REC LOW MIN ........... REC LOW MAX ..... Forecast low/high this week

Mon Apr 14 ....  -16.7C  (1893) .......   -7.8C (1880)  ............  -14/-6
Tue Apr 15 .....  -16.7C  (1893) ........  -6.7C  (1875) ............   -17/-6
Wed Apr 16 ....   -16.7C  (1875)  ......  -4.4C  (1910) ............  -13/-5
Thu Apr 17 .....   -13.3C  (1953) ........  -3.3C (1953)  ............  -12/-2

Normals for the period: High +10C, Low -2C.
Note that Winnipeg has never recorded a temperature colder than -15C after April 16th so temperatures this week represent some of the coldest weather on record for so late in the year here. The good news is that there are signs of a significant warmup by the Easter holiday weekend, with temperatures climbing to double digit values again. We can only hope the latest cold spell this week is winter's last hurrah after what has been a much too long stay this year. Over the past 11 weeks, Winnipeg has seen only 10 days above normal. The graph below shows daily temperature departures for Winnipeg over the past 90 days, which clearly shows an overly persistent pattern of well below normal temperatures since late January (in fact, since the beginning of December)  We're well overdue for a pattern change..

Daily temperature departures for Winnipeg over
the past 90 days. Mother Nature needs a major reboot

Saturday, April 12, 2014

Like it or not.. here comes the snow..

640 am Woodlands radar and webcam images
showing progress of snow across
southern MB early this morning
The latest bout of winter is on its way across southern Manitoba this morning with snow spreading into areas west of Portage La Prairie as of 7 am. Snow will continue to advance east this morning, reaching Winnipeg by mid to late morning. Snow may become heavy at times, with amounts of 5 cm possible by mid afternoon, although some areas could see 5-10 cm in heavier bands. Heaviest snowfall amounts are expected over higher terrain northwest of Portage La Prairie where 10-15 cm is expected today.

Follow this blog, my webcam page, MB highways, and AWM radar to keep track of this latest bout of wintery weather.

UPDATE: Snowfall reports from April 12th

Mafeking ............ 22 cm  (north of Swan River)
Cowan ............... 18 cm  (east of Swan River)
St Claude ............ 15 cm (south of Portage La Prairie)
Rossburn ............ 14 cm (southwest of Riding Mtn Park)
Carman .............. 10 cm
Brandon .............. 5-10 cm  (5 cm at YBR airport)
Neepawa ............  9 cm
Miami .................  9 cm
Gilbert Plains ....... 8 cm
St Alphonse ........  7 cm (south of Spruce Woods Park)
Portage LP .........  7 cm
High Bluff ............  7 cm (east of Portage La Prairie)
Morden ................ 6 cm
Winkler ................ 5 cm
Pinawa ................. 5 cm 
Marquette ............ 5 cm (east of Portage La Prairie)
Stony Mtn ............ 4 cm
Winnipeg .............  2 cm  (5 mm melted precip with ice pellets, rain and drizzle)

Thursday, April 10, 2014

After a springlike week, back to some winter this weekend..

Spinglike weather finally made an appearance over southern MB this week with the first double digit temperatures of the season in Winnipeg Wednesday (high of +10.4C), and almost 20C temperatures over the southwest RRV (19.3C in snowfree Morden) The mild temperatures have made a significant dent in the snowpack across southern MB, with most areas west of the Red River valley and south of the TransCanada now snow free. Here in Winnipeg, snowdepth at my location has dropped to 14 cm this morning after being at 40 cm just last weekend. Snowcover should continue to go down over the next couple of days as daytime temperatures remain above freezing.

But don't put away the snowshovels and boots just yet!  Believe it or not, indications are that Winnipeg and much of southern  MB will be seeing more of the white stuff this weekend, especially Saturday as a couple of disturbances track across the southern Prairies, while colder air flows in from the north. The first wave of snow is expected to spread over SW MB and along the US border Friday night into early Saturday, before another disturbance from central Saskatchewan brings a second wave of snow across the western Parklands into the Red River valley through Saturday, including Winnipeg.  There is still a lot of uncertainty about how much snow will fall with these systems due to temperatures hovering near the freezing mark, but it's possible Winnipeg and the RRV could see 5-10 cm of snow Saturday, while some higher elevations of western MB may see 15 cm of snow or more. Colder air will follow in the wake of these systems with daytime highs remaining below freezing early next week, well below normal for this time of year (normal highs now +9c). Temperatures are expected to moderate by the end of next week with near normal temperatures again by next weekend. Until then, get ready for another taste of winter.. hopefully the last parting shot of the season!  

Saturday, April 05, 2014

After coldest 4 month stretch in 115 years, spring weather finally returning to southern Manitoba

It's been a long tough winter in southern Manitoba, but springlike weather is finally returning this week as temperatures rise well above freezing for the next 7 days at least. The stubborn source of Arctic air that has persisted over central Canada for the last 4 months is finally showing signs of  retreating back north, which will allow more seasonable temperatures to spread across southern Manitoba this week. Normal highs are now +7C in Winnipeg, as we enter the climatogical period when snow cover has normally disappeared in the Red River valley.  This of course is not the case this year as snowdepths of 25-50 cm are still prevalent across much of the northern valley, including Winnipeg (officially 40 cm at my place as of this morning)  However, the upcoming spell of mild temperatures will make a big dent in the snowpack by the end of the week, and it's likely some parts of the Red River valley will be snowfree by next weekend.  The big melt this year is coming 2-3 weeks earlier than last year when the snowpack didn't disappear until April 27th in Winnipeg, thanks to prolonged cold weather that didn't see temperatures rise above +5C at Winnipeg airport until April 24th, the latest date on record. The good news with this week's big melt is that no significant precipitation is expected until at least next weekend, which will ease major flooding concerns. Nonetheless, the rapid melt this week will likely result in ponding of water in poor drainage areas as well as rising water levels in ditches.

Update on March stats: March finished with an average temperature of -12.7C in Winnipeg, the 19th coldest March on record, and the coldest March since 1996 (-13.0C)  The month averaged almost 7C below the 1981-2010 March average of -5.8C.  This made the 4 month period of December-March the coldest such period in Winnipeg since the winter of 1898-99 with an average temperature of -18.4C (tied with 1898-99)  During that 4 month period, Winnipeg saw 90 days with temperatures of -20C or lower.. the 6th most since 1872. For more details, see Winnipeg weather blog post on this year's harsh winter.

Saturday, March 29, 2014

March going out like a lion as major winter storm set to impact North Dakota, northern Minnesota, NW Ontario, SE Manitoba Monday

RDPS model valid Monday evening
showing large winter storm system
grazing southern Manitoba 
The never ending winter of 2013-14 is set to close out March with a bang as a major winter storm develops over the central US later this weekend, bringing heavy snow and strong winds to the Dakotas and northern Minnesota by Monday. The bulk of the heaviest snow with this storm is expected to fall mainly south and east of Manitoba, however the southern Red River Valley and SE Manitoba will likely get snow from this system along with strong winds and blowing snow. This would include Emerson, Steinbach and areas close to the Ontario border. Current indications are that Winnipeg will be on the northern edge of this large storm system, but some snow is also possible here Monday along with cold northerly winds. Note that Winnipeg will see worse conditions if the storm tracks further north, so it's important to keep updated on the progress of this storm as it develops over the next day or two.  

Blizzard watches (light green) and
winter storm watches (blue) are in
effect south of the US border
This storm has the potential to be a major snow producer over the Red River valley of North Dakota with amounts of 20-30 cm possible Sunday night into Monday night. In addition, strong northerly winds will cause extensive blowing and drifting snow with blizzard conditions likely over much of eastern North Dakota. In fact, a blizzard watch has been issued for much of eastern North and South Dakota from late Sunday through Monday night. Travellers should be prepared for poor driving conditions and possible road closures south of the border with this storm. This storm will also impact NW Ontario Monday into Tuesday as it heads east, so be prepared for poor travelling conditions if you're heading into northwest Ontario early next week.

Projected snowfall amounts (inches) from WPC/NOAA. Map shows swath of heaviest snow setting up between Grand Forks and Fargo through northern Minnesota into NW Ontario where 20-30 cm is possible Sunday night into Monday night  

Thursday, March 27, 2014

Cold end to March.. but a gradual moderating trend next week. Hopeful signs that we may be finally turning the corner in April?

March will be ending much like it began.. below normal (although not quite as cold as the the -37C we had on March 1st!) Clear skies and light winds will allow temperatures to drop to the -20C mark yet again early Friday, which would be the 15th time this month with a daily temperature of -20C or lower (normally, March only sees 5 such days in Winnipeg, and usually in the first half of the month). After a chilly start, Friday should see a nice afternoon with highs near -5C, still well below normal for this time of year, but feeling much nicer with sunny skies and light winds. The weekend looks somewhat unsettled as a weak clipper system tracks across southern Manitoba. This system will push a warm front across the area with a chance of some light snow ahead of it Saturday morning, before southerly winds bring in milder air for the afternoon as temperatures climb above the freezing mark to +2C in Winnipeg (which is actually normal for this time of year)  We may even see our first rain since early November Saturday night as a band of showers moves through the Red River valley ahead of a cold front. The mild air will be short lived however as the system advances east Sunday, with brisk northerly winds developing behind the system Sunday bringing falling temperatures. This will set the stage for a cold last day of March on Monday with temperatures some 10-15C below normal. March will likely finish with an average temperature around -12.7C in Winnipeg, about 7C below normal (normal March temperature is -5.8C based on 1981-2010 averages) and the coldest March in Winnipeg since 1996 (average temperature of -13.0C).  And according to local Winnipeg weather statistician "JJ" (from Winnipeg weather blog), this would make this the coldest December-March period in Winnipeg in 115 years (since the winter of 1898-99)  In other words, we've just been through the coldest 4 month stretch in Winnipeg in over a century!

(Check out this creative tribute to our endless winter to the "Sounds of Silence"  - Winnipeg Free Press)

But the news isn't all grim. The outlook for the rest of next week calls for a moderating trend with temperatures climbing through the week, with highs rising above the freezing mark by mid to late week. There are hopeful signs that this MAY be the start of a more significant and prolonged pattern change to milder weather as we get into mid April. But be forewarned, Aprils following very cold winters in Winnipeg are usually colder than normal.. thanks to a later than usual snowmelt. Hopefully, a milder start to April will accelerate the return of spring to southern Manitoba.  

Sunday, March 23, 2014

Frigid first weekend of "spring".. late season -30C weather over southern Manitoba as cold Marches on

The official first weekend of spring was anything but springlike over southern Manitoba as a frigid Arctic airmass brought abnormally cold temperatures to the area, averaging some 15-20C below normal for late March.  After a brisk Saturday when temperatures struggled to an afternoon high of -13C in Winnipeg (along with -25 windchills), clear skies and light winds allowed temperatures to bottom out to a frigid -28.4C at Winnipeg airport early Sunday morning. Although well below normal (average highs are now +2c, lows -8C), it was not a record low for the day (-32.2C on March 23 1974)  Temperatures this morning were even colder outside the city, with several sites recording lows below -30C, abnormally late for such temperatures even for southern MB.

Cold spots across southern Manitoba (March 23 2014)

Great Falls ........  -33.6C  (Pine Falls)
Gimli ..................  -33.4C
Fisher Branch ....  -32.2C
Wasagaming .....  -32.3C
Indian Bay...........  -32.0C (Falcon Lake) 
Pinawa ..............   -31.5C     
Victoria Beach ...   -31.0C

The cold conditions are just an extension of what southern Manitoba has been experiencing for the last 4 months now with consistently below normal temperatures. Over the past 9 weeks for example, only 9 days have been above normal in Winnipeg. The cold conditions will gradually ease over the next few days but temperatures will remain below normal much of the week before a moderating trend gets temperatures closer to normal by the weekend. So far, March is averaging around -13C in Winnipeg, well below the average March temperature of -5.8C (1981-2010 normal)  The below normal temperatures this week will ensure that March finishes as the city's 6th consecutive month below normal. 

Thursday, March 20, 2014

Spring arrives.. on the calendar only..

Projected snowfall amounts (cm)
tonight into midday Friday
Spring officially arrived at 11:57 am this morning, but it looks like Old Man Winter didn't get the memo as he gets ready to send another wintery blast across southern Manitoba tonight into Friday. A storm system over southern Saskatchewan this afternoon will track across North Dakota tonight into Minnesota Friday, spreading an area of snow across southern Manitoba tonight. Precipitation may even start as some rain or freezing rain south of the TransCanada highway to the international border this evening before changing to snow as the evening progresses. Snow will overspread southern Manitoba tonight with the bulk of the snowfall expected mainly over the southern RRV into SE MB towards the US border. (NOTE: Winter storm warnings are in effect south of the border) Snow will likely spread into Winnipeg this evening with 2 or 3 cm possible overnight. As the storm system heads east, northerly winds will increase on the backside of the system early Friday bringing much colder air from the Arctic. Strong north winds gusting to 70 or 80 km/h Friday morning will cause blowing and drifting snow in open areas, with poor traveling conditions likely outside the Perimeter, especially over the southern RRV. Things should generally improve in the afternoon and evening as winds ease off, however temperatures will be falling through the day with readings near minus 15C by evening making for icy conditions after today's melt. This latest blast of wintery weather will be the start of yet another spell of below normal temperatures across southern MB that will likely persist much of next week. This will ensure that March ends up as the 6th consecutive month below normal in Winnipeg.    

UPDATE: Actual snowfall amounts from Thursday night storm system (map courtesy of NWS Grand Forks, amounts in inches).  The storm system had a fairly narrow area of heavier snowfall mainly south of the US border into NW Ontario where 10-20 cm was reported. Snowfall amounts dropped off sharply over southern Manitoba with only 1 or 2 cm over the southern RRV. Little or no snow fell in Winnipeg.

Wednesday, March 19, 2014

Winnipeg snowfall - by the numbers

It's been a snowy winter in Winnipeg this year.  Snowfall started in mid November and has not quit, with persistent cold making the snow pile up to heights we haven't seen in a while.  Surely this has to be one of the snowiest winters on record for Winnipeg, right? Well, not really.  As of March 18th, our total snowfall this winter has been 151 cm (since October 1st)  That's well above the normal seasonal snowfall of 114 cm that usually falls in Winnipeg between October and May (based on 1981-2010 average for Winnipeg airport) And we still have a good 4-6 weeks of potential snowfall left this season to add to the total.

But as you can see from the table on the left, we still have a ways to go to even get in the top 10 snowiest winters of all time in Winnipeg, never mind the snowiest ever.  In 140 years of records, only 7 winters have cracked the 200 cm mark, with the snowy winter of 1955-56 topping the list at a whopping 252.6 cm, over twice the normal snowfall for the city. Most recently, the winter of 1996-97 has been the last winter to crack the 200 cm mark, thanks in large part to a record April blizzard of 48 cm that led to the "Flood of the Century" that spring. So although we still can get some good snowfalls between now and May, we'd have to get at least 60 cm over the next month to crack the top 5 snowiest winters in the city.

Looking at a graph of winter snowfall in Winnipeg since 1873 reveals some interesting observations. Most notable is how erratic Winnipeg snowfall is from year to year, with wild swings from well above "normal" to well below. In fact, it's tough to say what "normal" is, since snowfall varies so much every winter. One way to define "normal" is to look at a longer term average. Looking at the 30 year running average (red line), one can see that snowfall has averaged roughly 125 cm for much of Winnipeg's history since 1873. That average started to dip in the 1970s and 1980s with several below normal snow seasons during that time. As a result, our 30 year running average dipped to a low of 110 cm by the 1990s. Since then, average snowfall has been trending up again, with a trend towards that 125 cm average thanks to the last few winters. Perhaps this is nature's way of reverting back to more typical snowfall amounts for this part of the world.
Graph of winter season snowfall in Winnipeg since 1873
Red line shows 30 year running average (cm)
The graph also shows another interesting tidbit. The least snowy winter in Winnipeg was way back in 1877-78, during Winnipeg's warmest winter on record. Only 31 cm of snow fell that entire winter, during the "year without a winter" that was a result of an unusually strong El Nino that year that had worldwide impacts on weather, rainfall and crops. December 1877 was virtually snowfree in Winnipeg (only 0.5 cm the whole month) and no month that entire winter exceeded 8 cm of total snowfall. Incredible.  (*NOTE: Some recent information suggests that Winnipeg may have experienced a significant snowfall later that spring on May 2 1878. In a Department of Transport study on the "Climate of Winnipeg" (Labelle, Brown, and Hasinoff, June 7 1966), it notes that the heaviest May snowfall on record in Winnipeg was 10.7 inches (27.2 cm) on May 2 1878. Officially in the digitized climate archives online, snowfall for Winnipeg on that date is listed as only 1.8 cm, or 0.7 inches. It's possible the data was incorrectly entered into the climate database as 0.7" instead of 10.7". Note that the nearby St Andrews climate site recorded 12" of snow (30 cm) on May 2-3rd 1878, so the potential is there that Winnipeg had much heavier snow that day than the current archive shows. I will update this info if and when I hear more.)       

One last but important note. Snowfall observations are no longer taken at Winnipeg airport which was the official source for snowfall observations in the city since 1938. (St John's College took snowfall observations in Winnipeg between 1873-1938)  Due to automation and a change in observing responsibilities, snowfall records at the airport stopped in 2007. Since then, snowfall readings for Winnipeg have been based on snowfall observations taken from my Charleswood observing station, an official climate station with Environment Canada. I take two snowfall readings a day from October to May, including snow depth, and send the reports to Environment Canada who archive them in their climate database. Snowfall readings at my site will not always be representative of snowfall at the airport, but at least we have some record of snowfall for the city, in the absence of official snowfall data from Winnipeg airport. 

Monday, March 17, 2014

Seasonable weather this week.. turning colder again by the weekend..

It was a pleasant start to the work week in Winnipeg after Sunday's short but intense snowstorm brought up to 10 cm of snow to the city last evening, along with whiteout conditions due to strong southerly winds gusting to 75 km/h. The next few days will see generally benign weather over southern Manitoba as weak ridging crosses the province, while a stronger storm system over the Dakotas brings wintery weather south of the border over the next day or two. Temperatures will be seasonal with afternoon high temperatures near the freezing mark through Thursday. By Friday however, an Arctic ridge of high pressure from the Northwest Territories  is forecast to push south into the Prairies, bringing another spell of below normal temperatures through the weekend into next week. So although spring officially begins this Thursday March 20th at 11:57 am, it doesn't appear that Mother Nature is eager to usher in prolonged springlike conditions anytime soon over southern Manitoba. But that shouldn't be a surprise. Of the top 15 coldest winters in Winnipeg since 1872, NONE were followed by a warmer than normal March. And it looks like Mother Nature is keeping to the script.