Sunday, December 30, 2012

December to finish colder and snowier than normal..

December 2012 will finish colder and snowier than normal in Winnipeg, capping off what had been a record warm year through the fall.  December will finish with an average monthly temperature of -14.7C at YWG airport, or about 1.2C colder than the normal* December average of -13.5C (1981-2010 normal - see note at bottom of post)  Two cold spells around the 7th-13th and over the Christmas holidays brought the monthly average below normal, the third straight month with below normal temperatures. December snowfall of 32 cm (as measured at my site) was above the December mean of 19.8 cm, and brought the seasonal snowfall total so far up to 75 cm in the city.. almost matching last winter's entire snowfall total (80 cm) Normal seasonal snowfall in Winnipeg is around 110 cm.

For the year, 2012 will end up with an annual average of +4.6C in Winnipeg, some 1.7C above normal* and the 5th warmest calendar year on record since complete records began in 1873.  2012 was on pace to be the warmest calendar year through October, but a colder than normal finish dropped the year down to 5th place honours.

Top 5 warmest calendar years in Winnipeg (since 1873)  

1.  1987 ........... +5.4C
2.  1931 ........... +5.3C
3.  1878 ........... +4.7C
4.  1998 ........... +4.7C
5.  2012 ........... +4.6C

Normal* ........... +2.9C (based on 1981-2010 average)
normal annual temperature over entire period of record is 2.2C (1873-2012)

*NOTE:  Rob's Obs will be using 1981-2010 normals from now on. These are the updated 30 year normals that  replace the "old" normals which used the 1971-2000 averages. EC is still using the 1971-2000 normals, but plans to move to the updated 1981-2010 values soon.  I will have more details on this in a later post.  

Sunday, December 23, 2012

Season's Greetings from Rob's Obs!

Here's wishing everyone a safe and happy holiday season, and a wonderful new year in 2013!

2012 was sure an interesting year weatherwise over southern Manitoba and much of North America, with an exceptionally mild winter to start, record March heat wave, warmest 12 month period on record, and a snowy end.  Let's see what surprises Mother Nature has in store for 2013! Happy holidays!

Thursday, December 20, 2012

Quiet weather pattern to persist through Christmas holidays..

Generally quiet weather is expected over southern Manitoba over the next few days and through the Christmas holidays with no major storms forecast over the next little while.  Stubborn clouds and occasional light snow has persisted for the past few days, and will linger into Friday before some breaks appear over the weekend into early next week. Occasional light snow is possible at times, especially by Christmas Eve, but significant snow accumulations are not expected. Temperatures will be seasonably cold with highs in the minus teens, and lows in the minus 20s if skies clear. This will be good news for holiday travellers, with no major problems expected for highway or air travel heading into Christmas. 

Tuesday, December 11, 2012

Another round of snow moving in for Wednesday morning commute..

24 hr snow accumulations
from RGEM to Wed evening.
Highest amounts expected
over southern RRV
Another clipper system developing over the western Prairies is forecast to spread an area of snow over southern Manitoba tonight into Wednesday. Snow is expected to spread into southwest Manitoba this evening reaching Winnipeg and the RRV around midnight or shortly after. Snow will increase in intensity overnight with 2-5 cm possible by the morning rush hour.  Plan on extra time for your morning commute as roads will be snow-covered and slippery. Snow will be tapering off by midday Wednesday with total amounts of 4-8 cm possible for Winnipeg, and 10 cm or more possible mainly south of the city.    

Saturday, December 08, 2012

Snow spreading into Winnipeg and Red river valley today, turning colder for Sunday

Snow is spreading into the Red River Valley this morning including Winnipeg as a weak system passes across southern Manitoba. About 5 cm of snow is expected in Winnipeg by the afternoon with higher amounts of 10 cm possible mainly south of the city. As the system clears tonight cold weather will move into southern Manitoba with temperatures into the minus 20s for overnight and Sunday into the first part of the work week.

Sunday, December 02, 2012

See-saw weather continues this week

NAM prog valid 9 am Monday Dec 3rd.
Storm system tracking across Manitoba
will bring swath of snow to central
regions, and rain to the south before
colder air sweeps in.
A fast moving jet stream across southern Canada will be resulting in a variable weather pattern this week over southern Manitoba, with frequent swings in temperatures as weather systems sweep across the Prairies. In the short term, a storm system over northern Montana this afternoon will track into the Manitoba interlake regions overnight into Monday, bringing a swath of heavy snow across central Manitoba. Southerly winds ahead of the system will draw up milder air over southern MB, with temperature rising above freezing over the south, including Winnipeg and the RRV. As the storm system tracks into the interlake overnight into Monday morning, some rain is likely over the south while a band of freezing rain is possible over the western Parklands and southern interlake regions.  Monday will start off mild and wet over the RRV, however a cold front from the storm system to the north will sweep across the RRV, bringing a return to colder temperatures. In Winnipeg, temperatures near +1C at 9 am are expected to fall to -5C by 3 pm, along with gusty NW winds and a chance of flurries. Colder but seasonal temperatures are forecast for Tuesday before another warmup by Wednesday. Long range models are forecasting a potential for some snow by next weekend with colder temperatures to follow in its wake.

Radar notes: Note that radar images from the Weatheroffice website are now on SNOW rate and will overdo precipitation intensities during rainfall events. Consult Brad's radar viewer from A Weather Moment for radar images showing more accurate RAIN rate intensities during rain or freezing rain events in the winter (select 1.5 km CAPPI for RAIN rate) Weatheroffice radar images are fixed on snow rate across the country until spring. 

Friday, November 30, 2012

Freezing rain risk for parts of southern MB tonight..

GEM outlook for midnight tonight.
Red highlights areas of potential
freezing rain
A weather system over southern Saskatchewan will be pushing a warm front across southern Manitoba today into tonight, ushering a milder airmass from the south. Temperatures will be climbing towards the freezing mark overnight, especially closer to the US border. The milder weather however will also bring a threat of freezing rain or ice pellets tonight as the weather system track across southern MB. An area of freezing rain is expected to develop over southeast SK late today, and spread into SW Manitoba this evening.  A freezing rain warning has been issued for these areas. This area of freezing rain may push into Winnipeg and the RRV overnight, however at this point, it appears the greatest risk is over SW Manitoba into parts of the interlake. This system will push east of southern MB Saturday morning, with drier and briefly cooler conditions in its wake.  

UPDATE DEC 1st: TransCanada Highway is closed from Winnipeg to SK border this morning due to severe icing conditions. Travel not advised on many other roads in southern Manitoba, especially north and west of Winnipeg due to ice covered conditions from freezing rain overnight. For latest road and highway conditions, see Manitoba highways website.

Note also that radar images from the Weatheroffice website are now on SNOW rate and will overdo precipitation intensities during rainfall events. Consult Brad's radar viewer from A Weather Moment for radar images showing more accurate RAIN rate intensities during rain or freezing rain events in the winter (select 1.5 km CAPPI for RAIN rate).  

Rob's Obs snowfall statistics to Nov 30th...

Updated 2012-13 snowfall statistics .. (as measured at Rob's Obs)

November 2012 snowfall ............ 39.8 cm
Normal Nov snowfall *................ 21.4 cm
Departure ..................................+18.4 cm  (186%)
Nov 2011 snowfall ...................... 22.0 cm 
Seasonal snowfall since Oct 1st ...

2012-13 snowfall to Nov 30 ........ 43.0 cm
Normal snowfall to Nov 30 .......... 26.4 cm
Departure ..................................+16.6 cm  (163%)
Normal winter snowfall *.............. 109.4 cm 
% of normal winter snow to date ...  39%   
Last year to Nov 30 ...................   22.0 cm
% of normal winter snow...............   20%

2012-13 monthly snowfall summary ....

MONTH ................ SNOW ........ NORMAL*

Oct 2012 .................   3.2 cm .........   5.0 cm
Nov 2012 ................  39.8 cm ......... 21.4 cm
Dec 2012 ................  ?????   ......... 19.8 cm
Jan 2013 .................  ?????   .......... 23.1 cm
Feb 2013 ................   ?????   ......... 14.2 cm
Mar 2013 ................   ?????   ......... 15.8 cm
Apr 2013 ................   ?????   ......... 10.1 cm

TOTAL ...................   43.0 cm ...... 109.4 cm   (39%) 

* normal snowfall taken from 1971-2000 averages from Winnipeg airport

Thursday, November 29, 2012

Snow spreading into Winnipeg from the west this afternoon.. 2-5 cm possible through this evening.

An area of snow over southern Saskatchewan is spreading into western Manitoba this morning, with visibilities starting to drop in the Dauphin and Brandon regions and towards the SK border.  Snow will continue to spread eastward today reaching Winnipeg by mid to late afternoon, in time for the evening rush hour.  Snow will continue to increase through the evening with about 2-5 cm likely in Winnipeg by midnight, with higher amounts of 5-10 cm possible along the Yellowhead corridor into the Riding Mountains.  Snow will gradually taper off overnight as this system pulls off to the east. Friday will be mainly cloudy but turning milder as southerly winds start drawing up warmer air from the south.  Another weak system will be crossing southern Manitoba Friday night into Saturday with more snow likely through the interlake regions, with mixed precipitation including the risk of freezing rain over Winnipeg and the RRV.  A stronger storm system will likely impact southern Manitoba Sunday night into Monday, with rain or freezing rain over the RRV changing to snow along with strong northwest winds and falling temperatures.

Follow snow on radar. Keep in mind that radar images from the Weatheroffice website are still on RAIN rate and will underplay snow intensities (radar will be changing to SNOW rate on Mon Dec 3rd). Consult Brad's radar viewer from A Weather Moment for radar images showing more accurate SNOW rate intensities.  For latest road and highway conditions, see Manitoba highways website.

Tuesday, November 27, 2012

Cold and dry next couple of days.. then snow chances and temperatures increase late week into weekend

Cold high pressure building over the Prairies today will bring cold but snowfree conditions today into Thursday over southern Manitoba. Temperatures will be several degrees below normal with highs around minus 10, and lows tonight near -20C, although Wednesday will likely moderate briefly to around -7c.  By Thursday evening, a wave of snow will be pushing across southern Manitoba ahead of a warm front that will be moving in from the west. This front will usher in milder air for Friday into the weekend, with temperatures climbing towards the freezing mark. Additional snow is possible Friday night into Saturday as another wave of precipitation pushes across southern Manitoba.   Long range guidance is hinting at a possible stronger storm system affecting southern  MB Monday bringing in a flow of milder air across the RRV with even some rain possible.    

Friday, November 23, 2012

A little more snow Saturday.. gusty south winds will give occasional blowing and drifting snow..

GEM prog valid noon Sat Nov 24th
showing band of snow moving
across southern MB
A low pressure system over southern Alberta will be tracking into southern Manitoba Saturday bringing a band of snow ahead of it. This band of snow is expected to spread into western MB overnight reaching the Interlake and RRV areas Saturday morning. The snow will push east towards the Ontario border by late afternoon with about 2-5 cm possible as the area of snow moves through. The heaviest amounts are expected mainly north and east of Winnipeg. Note that the snow will also be accompanied by brisk southerly winds gusting to 50 or 60 km/h in Winnipeg and the RRV, which will give occasional blowing and drifting snow and locally poor visibilities at times. (eastbound lanes of west-east highways will be most prone to drifting snow Saturday) Caution is advised if travelling Saturday, particularly in areas near and outside the Winnipeg perimeter.   

NOTE: Woodlands radar is currently not updating. Keep in mind that radar images from the Weatheroffice website are still on RAIN  rate and will underplay snow intensities. Consult Brads's radar viewer from A Weather Moment for radar showing more accurate SNOW rate intensities.  For latest road and highway conditions, see Manitoba highways website.

Thursday, November 22, 2012

Blustery and colder today with snow moving in..

The pleasant stretch of above normal temperatures and quiet weather will be coming to end today thanks to a cold front that pushed through southern Manitoba overnight. Gusty north winds to 50 or 60 km/h behind the front will usher in much colder air from the northern Prairies, with temperatures falling through the day towards the -10C mark by evening. The gusty northerly winds will be make it feel even colder with wind chills falling to the -20 range. In addition, periods of snow will be spreading across Winnipeg and the RRV this morning,  with about 5 cm possible by the drive home.  This will result in deteriorating road conditions today, with occasional reduced visibilities in snow and blowing snow. Road conditions are already slippery this morning from some early morning freezing drizzle that left a coating of ice on untreated surfaces.. and  a layer of wind blown snow will continue to make for slippery conditions through the day into the evening. Caution on the roads today.. winter driving skills will be required once again.

Follow snow on radar today. Keep in mind that radar images from the Weatheroffice website are still on RAIN  rate and will underplay snow intensities. Consult Brads's radar viewer from A Weather Moment for radar showing more accurate SNOW rate intensities.  For latest road and highway conditions, see Manitoba highways website.

Sunday, November 18, 2012

Dry and mild start to the week.. turning colder with some snow likely by Thursday

Generally pleasant and dry weather is expected over southern Manitoba over the next few days as a series of low pressure systems passes to the north of the region.  This will bring a flow of above normal temperatures over the south with daytime highs generally above freezing today through Wednesday. Warmest temperatures will be over far southeast MB which has minimal snow cover, with highs of +5 to +8C possible over the next few days. By Wednesday, scattered showers are possible ahead of  a low pressure system that will be developing over southern SK. This system will drag a cold front through southern Manitoba by Thursday with some snow possible as colder air works in behind it. This doesn't look like a major system at this point, with snowfall amounts of 2-5 cm being forecast by the long range models along with gusty north winds. Still, it will likely be enough to bring wintery driving conditions over southern MB once again, after a period of relatively benign weather. Until then, enjoy the nice weather for the next few days!   

Monday, November 12, 2012

Cold start to the week with a milder finish. No more snow for awhile..

It will be a cold start to the week after a weekend storm system brought widespread snow across southern Manitoba. Temperatures today will remain around the -5C mark with brisk NW winds making it feel more like -15 with the windchill.  For tonight, clearing skies and diminishing winds over a fresh snowpack will allow temperatures to drop to the coldest of the season so far, with -20C temperatures likely by Tuesday morning. Below normal temperatures will persist through midweek before a moderating trend towards late week with temperatures rising towards the melting point. In fact, long range models are indicating warmer than normal weather over the weekend into early next week with above freezing temperatures expected. In addition, no new snow is expected the rest of this week which will help in snow clearing operations from the weekend storm. All in all, a nice week ahead after a winter-like start! 

Sunday, November 11, 2012

Winter storm delivers winter wallop to southern Manitoba

South Winnipeg webcam around
10 pm Nov 10th when heavy snow
was giving 5 cm/hr snowfall rates

Winter arrived with a vengeance Saturday as a well advertised winter storm brought widespread snow across most of southern Manitoba Saturday into Saturday night.  The "Colorado low" storm system which tracked across northern Minnesota last night, brought two waves of snow.. one that began in the early morning hours Saturday and pushed into the Interlake areas, and another heavier burst of snow Saturday night that brought very heavy snowfall rates of up to 5 cm/hr at times across the Red River valley including Winnipeg. When the snowfall finally tapered off Sunday morning, it left some impressive snowfall totals over most of southern Manitoba, transforming what was a bare snowfree landscape Friday into a winter wonderland within 36 hours.

Some storm snowfall totals reported as of Sunday morning Nov 11th..

Mafeking ................. 65 cm   (Highway 10 between Swan River and The Pas)
Ashern ...................... 40-60 cm
Hodgson ................... 40 cm
Swan River ............... 40 cm
St Alphonse .............. 40 cm 
Portage La Prairie ..... 37 cm
Dauphin .................... 33 cm
Baldur ....................... 33 cm
Holland ..................... 32 cm
Belmont .................... 32 cm 
Gilbert Plains ............. 25-35 cm 
Roblin ....................... 24 cm
Winnipeg ................. 22 cm  (greatest 24 hr snowfall since Dec 2006)
St Claude .................  22 cm
Marquette ................. 21 cm
Brandon .................... 20 cm
Neepawa ..................  20 cm
Woodlands ...............  20 cm
Morden ....................  14 cm
Carman ....................  12 cm
Pinawa ...................... 11 cm 
Steinbach  ................. 10 cm
Emerson .................... 10 cm

Backyard scene from Treherne MB
was typical across much of
southern MB Sunday morning
Winnipeg's snowfall of 22 cm was the city's greatest 24 hr snowfall since Dec 30-31 2006 when 32 cm fell. Heaviest snowfall with this storm was in a wide swath from the Riding and Duck Mountains through the northern Interlake, as well as a narrower band from the western RRV through Portage la Prairie into the central interlake thanks to some slow moving heavy snowbands that set up Saturday evening.  Neighbouring eastern Saskatchewan was also hard hit with 30-45 cm reported from Regina to Yorkton. Snowfall was much less south and east of Winnipeg especially towards the Ontario border where precipitation was mixed with freezing rain Saturday.

Trucks line up in Headingley MB
waiting for the TransCanada to open
The storm was bad enough to force the closure of the TransCanada highway Saturday night between Winnipeg and Brandon due to the severe winter conditions.


Storm Chronology for Winnipeg (as observed at my site in Charleswood)

Light snow began around 2-3 am on Nov 10th, with 2 cm falling between 4 and 8 am. Snow continued through the morning with another 3 cm by 1 pm. Snow stopped in the afternoon with some light flurries mixed with freezing drizzle at times. By 5 pm, steadier snow started falling again with another 5 cm by 9 pm. Around 9 pm, snow intensified and became very heavy, with 5 cm falling between 9-10 pm, and another 3 cm from 10-11 pm. Snow started easing around 11 pm with another 1 cm by midnight.  Another round of steady snow developed by 1 am, with an additional 3 cm by 4 am Nov 11th.  Snow tapered off by 6-7 am Nov 11th.  Storm total by 8 am Nov 11th: 22 cm snow, trace of freezing drizzle.

Nov 10 - 11 2012 snowfall accumulations (per my obs and YWG airport obs)

2 am - 4 am:    Trace
4 am - 8 am:    2 cm 
8 am - 1 pm:    3 cm 
1 pm - 5 pm:    Trace of snow, trace of freezing drizzle
5 pm - 9 pm:     5 cm 
9 pm - 10 pm:   5 cm (S+) 
10 pm - 11 pm: 3 cm
11 pm - mid:     1 cm
mid - 4 am:       3 cm 
4 am - 7 am:     Trace  

24 hr Radar accumulation summaries to 9 am Sunday morning

24 hr precip accumulation from
Foxwarren radar to 9 am Sunday.
Precip amounts in mm and
may not accurately reflect
actual snowfall totals
24 hr precip accumulation from
Woodlands radar to 9 am Sunday.
Precip amounts in mm and
may not accurately reflect
actual snowfall totals

Saturday, November 10, 2012

Winter Storm Update

Snow has spread over southern MB this morning with the heaviest snow occurring through western MB and the interlake areas. As of  9 am, about 15 cm of snow has fallen through the Roblin/Dauphin areas, with 8 cm in Brandon, 5 cm in Portage and about 2-3 cm in Winnipeg. Snowfall drops off to a dusting south and east of Winnipeg where precipitation is mixing with freezing drizzle or ice pellets. Winnipeg will be on the edge of  heavier snow to the west and north today, and more intermittent light snow to our south and east. As such, the weather in Winnipeg today will vary between periods of light snow, and heavier bursts from time to time. In general, about 5-10 cm of snow is expected in Winnipeg today, with higher amounts of 10-20 cm to our north and west, and lighter amounts of 2-5 cm to our south and east.  For tonight the storm system will be tracking into northern Minnesota and NW Ontario, bringing another wave of heavier precipitation over southern MB. This could bring another 10-15 cm of snow to Winnipeg and the RRV overnight into Sunday morning before the snowfall tapers off. So we'll be dealing with this storm for the next 24-36 hours yet.. Overall, Winnipeg could see about 15-25 cm of snow from this system, with the heaviest snowfall over western MB into the interlake areas where 30-40 cm is possible by Sunday evening.

Friday, November 09, 2012

Major winter storm takes aim at southern Manitoba..

The well advertised winter storm that we've been following for a week now is getting closer, and snow from the system will be spreading into southern Manitoba this afternoon into tonight, with heavy snow expected over the weekend. A WINTER STORM WARNING is in effect for much of southern Manitoba, including Winnipeg and the RRV, with general snowfall accumulations of 20-30 cm expected across much of the area by Sunday morning, with up to 40 cm possible over portions of southwestern MB. Further east, the storm will likely bring a band of freezing rain or ice pellets towards the Ontario border overnight and Saturday before changing to all snow Saturday night into Sunday.  In Winnipeg, light snow is expected to develop this evening, becoming steadier and heavier after midnight with 5 cm possible by Saturday morning. Snow will continue all day Saturday with another 10-20 cm likely by evening along with northeast winds gusting to 50 km/h at times. Additional snow is expected Saturday night into Sunday morning before the storm gradually moves out with storm totals of 20-30 cm possible across the Red River valley, including Winnipeg.

Projected snowfall accumulations Friday night into Sunday 
(GEM model left, NAM model right) 

GEM snowfall accumulations
Fri evening to Sunday morning
orange area is 25cm+
NAM snowfall accumulations
Fri evening to Sunday
orange area is 25cm+


Regardless of the total amount of snow that falls, residents should be prepared for a prolonged period of snowy weather over southern MB beginning tonight, lasting through Saturday into Sunday morning, and gradually tapering off later Sunday. Road conditions will deteriorate as the storm progresses, especially Saturday and Saturday night when the bulk of the snow is expected across southern MB.  Be prepared for much slower travel times and possible road closures. (In fact, I wouldn't be surprised to see the TransCanada closing tomorrow from Winnipeg to the Saskatchewan border) Northerly winds of 30 to 50 km/h will accompany the storm with reduced visibility at times in snow and blowing snow. Improving conditions are expected later Sunday as the storm pulls off. Note that this storm will also be affecting neighbouring southern Saskatchewan, North Dakota, NW Minnesota, and NW Ontario so keep that in mind if you have travel plans to those areas this weekend.   For MB highway conditions and any road closures, visit Manitoba Highways website

Follow the storm on radar!  Follow the storm on radar using Radar Viewer from A Weather Moment, which is displaying radar echoes in SNOW mode.  Note that radar imagery on the Weatheroffice website is still on RAIN rates, and will significantly underplay snow intensities. Radar imagery on Weatheroffice is fixed on rain rates nationally until Dec 1st when it switches over to snow rates.

Thursday, November 08, 2012

Snowy Saturday on tap.. but how snowy?

Rob's Obs Snow Poll average17.2 cm (based on 101 entries)

This is what many roads in southern
Manitoba may look like Saturday
It's looking increasingly likely that a significant snowfall will be impacting southern Manitoba by Saturday, with the season's first widepsread snowfall of the season expected for the RRV and much of southern MB.  Environment Canada has issued a SNOWFALL WARNING for much of southern MB, including Winnipeg, for the potential of 15 to 25 cm of snow Friday into Sunday. Although there remains some uncertainty about how much snow will fall in any one location (including Winnipeg), there are a few things that are looking more likely about this impending snowfall event..

Expected storm position
valid 6 am Sunday Nov 11th
- Storm track: Low will be tracking towards Duluth (see image left). That increases odds of heavier snow over SE MB and less snow towards the SK border 
- Precip Phase: Will be an all snow event. With the above storm track, likelihood of mixed precipitation (freezing rain/ice pellets) is reduced over most of southern MB 
- Timing: Snow will be spreading in from the southwest late Friday, persisting through Saturday and Saturday night, then gradually pulling off Sunday. Snow expected to develop in Winnipeg Friday night (midnight or pre-dawn hours Saturday)

Snowfall projections (GEM model)
Friday through Sunday, 5 cm ranges
(yellow line is 20 cm)

Snowfall projections (NAM model)
Friday through Sunday, 5 cm ranges
(orange line is 25 cm)

OK, but what about what everyone wants to know: how much snow will fall in Winnipeg?  Models still have been flip-flopping on that issue, but the consensus is growing that Winnipeg will see around 15 cm of snow in total from early Saturday into Sunday morning.  Model estimates for Winnipeg range from a minimum of 10 cm  to a high of 30 cm, but overall, they seem to converging around that 15 cm mark.  It's likely however that some areas of southern MB will see more than that, perhaps 20-30 cm, including parts of the RRV and SE Manitoba (and possibly even Winnipeg if a heavier snowband hits the city)

Regardless of the total amount that falls, residents should be prepared for a period of snowy weather over southern MB beginning Friday night, lasting through Saturday, and easing off Sunday. Road conditions will deteriorate as the storm progresses, especially Saturday when the bulk of the snow is expected across southern MB.  Be prepared for much slower travel times and possible road closures.  Northerly winds of 30 to 50 km/h will accompany the storm with reduced visibility at times in snow and blowing snow. Improving conditions are expected Sunday as the storm pulls off. Note that this storm will also be affecting neighbouring North Dakota, NW Minnesota, and NW Ontario so keep that in mind if you have travel plans to those areas this weekend.

Tuesday, November 06, 2012

Winter storm threat increasing for southern MB this weekend.. snowfall amounts still uncertain

Long range computer models are coming into agreement that a significant winter storm will likely be impacting southern MB by Saturday.  Models show a storm system developing over the central US Rockies later this week and tracking into Minnesota by Saturday, bringing a swath of snow across the northern Plains states and southern Prairies. Although models agree on this general premise, there is still some uncertainty about exactly where the storm will track, which will have major implications on where the heaviest snow falls over southern MB. Currently, there are 3 main scenarios that are possible. With each scenario, I give a likelihood of that outcome occurring (purely subjective based on my own analysis and interpretation)

Scenario 1 -  Weaker low tracking near Duluth 

Southern MB impacts:  Colder with less snow over western MB and RRV, more snow over SE MB     
Winnipeg snowfall:  5-15 cm (less snow north and west, more snow south and east)
Likelihood:  25% (Updated Nov 9th) 25%


Scenario 2 - Stronger low tracking near International Falls 

Southern MB impacts:  Heaviest snow over RRV and interlake, less snow over SE MB     
Winnipeg snowfall: 15-25 cm (less snow west and east)
Likelihood:  50% (Updated Nov 9th) 55%

Scenario 3 - Strong low tracking near Lake of the Woods

Southern MB impacts:  Heaviest snow over western MB and interlake, less snow over RRV/SE MB with freezing rain or ice pellets possible      
Winnipeg snowfall: 10-15 cm (more snow north and west, less snow south and east)
Likelihood:  25%  (Updated Nov 9th) 20%


In all cases, the bulk of the snow is expected to fall Saturday with snowfall tapering off Sunday. Winds will depend on the strength and track of the low, but generally the strongest winds will accompany the area of heaviest snow, which will lead to snow and blowing snow issues.

Model Snowfall projections Friday through Sunday 
GFS model (left), GEM model (right)
(based on 12Z model runs from Tue Nov 6th)

Projected snowfall accumulations
Fri - Sun from GFS model
5 cm ranges, yellow is 20 cm line
Projected snowfall accumulations
Fri - Sun from GEM model
5 cm ranges, green is 10 cm line

I will continue to monitor the situation and have updates as the week progresses. During that time, updated model solutions will hopefully be converging towards a more consistent forecast that I can relay with more confidence. In the meantime, you may want to start making sure you have the winter gear handy for the end of the week, and your vehicle is prepared for winter driving conditions (including snow tires)

Sunday, November 04, 2012

A little rain Monday evening then a quiet week. Winter storm threatens southern MB by weekend..

Weather map for 6 pm Monday
showing band of rain and wet
snow pushing across southern MB
A warm front over northern Alberta will push into southern MB Monday bringing a band of precipitation ahead of it. The bulk of the precipitation should fall as rainshowers through the Interlake Monday afternoon into the RRV by evening, with some wet snow mainly north and east of Lake Winnipeg. Further west, the warm front will likely result in some patchy dense fog developing overnight into Monday morning across SW Manitoba especially towards the SK border.

GGEM map for Sunday morning
Nov 11th showing strong
system affecting southern MB
After Monday, things look generally quiet over southern MB the rest of the week with generally fair weather and seasonable temperatures. By next weekend however, long range models are hinting at a potentially significant winter storm affecting southern MB Saturday into Sunday, with the possibility of heavy snow and strong winds. The storm is still a ways off and there are track and intensity differences from the various models that will have a major impact on forecasting who gets snow and how much. So at this point, all we can say is that the POTENTIAL for a significant snowfall of 10 cm or more exists for much of southern MB next weekend, including Winnipeg. I'll be posting blog updates on this developing situation as the week progresses.  

Meteogram showing various model
output for Winnipeg including
6 hr precip amounts (bottom)
The chart to the left is a meteogram plot showing various meterological parameters for Winnipeg out to 10 days from UQAM's excellent site.  The meteogram is interesting since it plots various model solutions (such as the GFS, UKMET, ECMWF, GLB, etc) as well as previous model runs. It's an effective way to see how models are agreeing, and trends in the expected weather conditions. The meteogram plots MSL pressure (top), 850 mb temperature (center) and 6 hr precip (bottom) Updated Winnipeg meteograms available after noon (12Z meteogram) or after 12 am (00z meteogram).   Meteogram data also available from            

Thursday, November 01, 2012

Some snow moving into southern Manitoba overnight into Friday

Weather map for midday Friday
showing area of snow pushing
into the RRV from the west
A weak weather system over southern SK is forecast to spread an area of snow over southern MB overnight into Friday, bringing some accumulating snow to much of the area.  Snow is expected to move into SW Manitoba overnight, gradually spreading into the Red River valley including Winnipeg by Friday afternoon (see top image). The snow is expected to continue through the evening rush hour into Friday night before tapering off early Saturday. Snowfall amounts are expected to range from 5-10 cm over SW Manitoba to about 2-5 cm in the Red River valley including Winnipeg (see lower image), with the highest amounts mainly south and west of Winnipeg. Little snow is forecast north and east of Winnipeg as the system slides to the southwest of the Red River valley and weakens.

24hr snowfall accumulations (cm)
from RGEM model
valid 7 am Fri - 7 am Sat
Luckily, winds will be light accompanying the system with temperatures near the freezing mark so blowing or drifting snow should not be an issue. Still, this will likely be the first widespread accumulating snow the city has seen since early October, so be prepared for some winterlike driving conditions by late Friday, especially if you're headed west of the city.

11 am Nov 2 UPDATE: Snow has spread over southwest MB this morning with MB highways reporting snowcovered roads west and northwest of Brandon. See recent photo taken on Hwy 16 near Foxwarren..

5:30 pm UPDATE:  Snow over southwest MB has edged eastward to a Portage-Carman-Emerson line. Snow is occurring moderate to heavy at times along and west of this line, with visibilities down to 1 km at times.  Snow will slowly move east into the Red River valley this evening with light snow possible in Winnipeg, although bulk of snow will likely remain south and west of Winnipeg.

24hr snowfall accumulation (mm/cm)
up to 7 am this morning. Note how
close Winnipeg was to swath of
heavier snow to southwest.
Snowfall amounts past 24 hours..

Winnipeg...  dusting
Carman .......  3 cm
Portage .......  5 cm
Winkler .......  6 cm
Brandon ..... 12 cm 

Wednesday, October 31, 2012

Cool October marks first below normal month in Winnipeg since May 2011

October 2012 temperature
summary for Winnipeg
A cooler than normal October will go down as the first below normal month in Winnipeg since May 2011.. or 17 months ago. Over that time, Winnipeg has seen 16 consecutive months near or above normal including 14 straight months above normal from July 2011 to August 2012, an unprecedented stretch of warmth in Winnipeg since records began 140 years ago in 1872.  October finished with a mean temperature of +4.0C, or about 1.3C below the normal October mean of 5.3C (based on 1971-2000 averages).  The bigger story for October was the return of some much needed precipitation, with 57.5 mm recorded at YWG airport, about 20 mm wetter than normal for October. It was the first wetter than normal month in Winnipeg since May, and comes after an exceptionally dry September  that was the second driest on record. Precipitation amounts were even greater elsewhere in the city with 72 mm at the Forks and 85 mm in Charleswood. Outside the city, the big weather story in October was the early October snowstorm on the 4th that brought up to 30 cm of heavy snow over southeast MB.    

Wednesday, October 24, 2012

Colder weather on tap..

Colder weather is on tap over southern Manitoba for the next few days as a cold northwest flow sets up behind a storm system intensifying over northern Ontario Thursday.  This system will drag the coldest air of the season so far over southern Manitoba, with daytime highs only near or slightly above freezing, some 5-7C below normal for late October.  The cold weather will be accompanied by mainly cloudy skies and occasional flurry activity, with locally heavier snow bands possible to the southeast of Lakes Winnipeg and Manitoba. The cold weather is expected to persist through the weekend into early next week, with a moderating trend possible later next week.

Sunday, October 21, 2012

More rain Tuesday.. turning colder by late week with snow possible..

60 hr GLB valid Tuesday morning
Oct 23rd with rain spreading into
southern MB
Generally fair and seasonable weather is expected today and Monday, before another round of wet weather moves in Tuesday. After that, things will get progressively colder through the end of week into next weekend, with well below normal temperatures expected through the end of October. The colder weather will bring some snowflurries later this week, with some accumulating snow possible at times.  For today, cloudy skies and scattered light showers this morning will give way to thinning clouds this afternoon, with afternoon highs near 10C accompanied by northwest winds of 20 km/h.  Morning sunshine Monday will give way to increasing clouds ahead of the next system, which is expected to spread some rain over southern MB overnight Monday into Tuesday. At this point, it looks like about 10-20 mm of rain is possible for Winnipeg  and the RRV, with higher amounts of 20-30 mm over southwest MB into the interlake regions.

Yikes!  132 hr GLB valid Friday
Oct 26th shows potential snowstorm
over southern MB/NW Ont
Rain will gradually pull off Wednesday followed by a northwest flow of colder air for Thursday into the weekend. This will be the coldest outbreak of the season so far, with high temperatures only near freezing or even below through the weekend into early next week, along with the possibility of accumulating snow. In fact, long range guidance is suggesting the potential of a significant snowstorm over portions of southern MB or NW Ontario by Friday. Stay tuned..       

Thursday, October 18, 2012

Another soaking rainfall over southern MB.. more rain and wind today

A strong low pressure system over northern Minnesota brought another soaking rain over southern Manitoba Wednesday into last night, with amounts of 15 to 40 mm recorded in the past 24 hours.  Amounts were heaviest along the western RRV with amounts of 30 to 40 mm recorded from Portage through Carman to Morden. Lesser amounts fell in Winnipeg with about 15 mm through midnight. More rain is likely today as another batch of showers moves in this morning with 5 to 10 mm possible by evening, along with increasing northerly winds gusting to 70 km/h at times this afternoon into this evening.  The rain has brought some much needed moisture to southern MB, after an exceptionally dry September that saw only 4 mm fall all month in Winnipeg. Rainfall this month is now up to 36 mm at the airport as of this morning, and 50 mm at the Forks. Normal October precipitation is 36 mm, so this month will be the first month since May that has seen above normal precipitation in Winnipeg.  Things are expected to dry out for the weekend into early next week, but long range guidance is hinting at the possibility of a strong storm system moving across the northern Dakotas by the end of next week bringing another round of significant  precipitation over southern MB, with a soaking rain possibly changing to snow.  Stay tuned..   

Thursday, October 11, 2012

Brisk southerly winds Friday to usher in milder weekend..

After more than a week of below normal temperatures, conditions will be becoming milder this weekend as winds shift into the south and southwest.  Temperatures will finally be returning into the double digits after being generally in the single digits since Oct 3rd.  The change to milder weather will be heralded by strong southerly winds Friday gusting to 60 or 70 km/h, which combined with afternoon temperatures in the 5-10C range will feel quite brisk. Things will feel a lot milder on the weekend, as temperatures climb into the low to middle double digits, along with lighter winds and sunshine. Normal highs for this time of year are 11C, with normal lows of 0C.  Near to above normal temperatures are expected early next week, before a return to colder weather by the middle to latter part of the week.  

Sunday, October 07, 2012

More rain on the way.. with some snow possible Monday night

GEM precip type forecast for
Monday evening Oct 8 2012.
Green is rain, blue is snow,
yellow is wet snow/rain
A clipper system over northern Saskatchewan will track southeastward into southern MB overnight and Monday bringing another round of much needed precipitation over the region. Rain from this system will spread into western MB this evening and into the RRV overnight, continuing though Thanksgiving Monday. Rain will change over to snow over higher elevations of western MB Monday with some accumulations likely over the Duck and Riding Mountains. Rainfall amounts of 10 to 20 mm will be possible through much of southern MB, especially from western MB highlands into the RRV, including Winnipeg. By Monday night, colder air wrapping in behind the system will change rain over to wet snow even over the RRV, with a coating of wet snow possible by Tuesday morning. Below normal temperatures in the single digits will persist through the week, before some moderation by next week.     

Thursday, October 04, 2012

Early season snowstorm slams southeast Manitoba

Heavy snow and downed trees
made roads nearly impassable
near Vassar, MB - Oct 4 2012
A powerful early season snowstorm slammed southern Manitoba Thursday Oct 4th bringing significant snowfall to southeastern parts of the province. Rain from the system changed to snow early Thursday and continued through the day, with accumulations of 10-30 cm reported over the Steinbach, Whiteshell, Sprague and Bissett regions. Snow was mixed with rain further west over the Red river valley with a slushy coating of snow in Winnipeg by afternoon.  Strong northerly winds gusting to 60 or 70 km/h accompanied the storm, which combined with the heavy wet snow resulted in tree damage and power outages over much of SE Manitoba, with numerous hydro poles and hydro lines downed.  Road conditions over southeastern MB were poor due to the heavy snow and poor visibility, with travel not advised from Steinbach to the Ontario border. (see some impressive snowfall photos from Steinbach Online photo gallery showing extent of snow over southeast Manitoba) 

Snowfall totals from the storm included..

Satellite image Oct 6 2012 showing
extent of snowcover over SE MB.
Note also bands of lake effect snow
off Lakes Winnipeg and Manitoba
which set up Friday behind storm.

Sandilands ............. 30 cm (trees down)
Hadashville ............ 30 cm (see photo)
Woodridge ............. 30 cm (see photo)
La Broquerie .......... 27 cm
Falcon Lake............ 25-30 cm (est) 
Vita ........................ 25 cm
Pinawa ................... 20-30 cm
Bissett .................... 20 cm
South Junction ........ 20-30 cm  /nr Sprague/
Steinbach ...............  8 cm

Up to a foot of snow fell over parts
of  SE Manitoba Oct 4 2012.
The early snowfall, although an inconvenience, brought some much needed moisture to the region, which has been exceptionally dry over the past 6 weeks.  The snowfall brought relief to firefighting efforts in the Vita area, which had been evacuated just two days earlier by windswept wildfires.  In Winnipeg, about 8 mm of rain and wet snow was recorded at Winnipeg airport by evening, with 10-20 mm of precipitation reported across the city (19 mm at the Forks and 18 mm at my site in Charleswood)

Early Snowfalls over Winnipeg and southern MB

Snowfalls this early are unusual, but not unprecedented.  Winnipeg has seen measurable snow as early as Sept 20th when 1.5 cm was recorded in 1945. On Oct 2 1950, Winnipeg reported 12.7 cm of snow, while 13.8 cm of snow was recorded during a wintery blast on Oct 7-8, 1985. Heavier snowfalls have been recorded elsewhere over southern Manitoba during early October and September, especially over the higher elevations of SW Manitoba. Most recently, a record early snowstorm on Oct 5 2005 dumped 20-45 cm of snow over southwest MB, heaviest around the Pilot Mound area. October 1959 saw 3 major snowstorms dump over 100 cm of snow over SW Manitoba, in what was the snowiest month on record in Brandon. One of the earliest snowstorms ever recorded in southern MB occurred on Sept 12-13 1903, when 10-30 cm of snow fell over higher elevations of western MB near the SK border. 

Early season snowfalls in Winnipeg (since 1872)

Sep 20 1945 * ......  1.5 cm   (see note below)
Sep 24 1984 ........  5.8 cm
Sep 25 1872 ........ 18.3 cm
Sep 29 1908 ........  5.1 cm
Oct  1 1996 .......... 4.0 cm
Oct 2 1950 .......... 12.7 cm
Oct 4 1952 ........... 8.6 cm
Oct 5 1876 ........... 11.4 cm
Oct 5 2005 ............  7.0 cm 
Oct 7-8 1985 ......... 13.8 cm

* Officially, the date of this earliest snowfall is listed in the climate archives as September 19th 1945.  However, the snow actually fell in the pre-dawn hours of Sept 20 1945 from 4:20 am to "breakfast time" according to the Winnipeg Tribune. Prior to July 1961, precipitation that fell before 630 am was included in the previous day's precipitation total. 

Tuesday, October 02, 2012

Storm system to bring significant rain.. and (gasp) snow.. to Red River Valley and SE Manitoba Thursday into Thursday night.

4 km hi-res NAM image valid
15Z Thursday morning. NAM is
most aggressive on storm intensity
and snowfall over southern MB
A major storm system is forecast to develop over the eastern Dakotas Wednesday, tracking into northern Minnesota Wednesday night into NW Ontario Thursday. This system is poised to bring the most significant precipitation to the Red River valley and SE Manitoba in several weeks, and the moisture will be most welcome.  Current model guidance is showing anywhere from 10 to 50 mm of precipitation may fall with this storm system Wednesday night through Thursday and Thursday night. The problem is there are indications that some of this moisture may fall as snow, and the snow could be significant over portions of the RRV and SE MB, as well as neighbouring northeast ND, northern MN and NW Ontario.  Rain from this system is expected to spread into southern MB from North Dakota Wednesday night and continue Thursday, with increasing northerly winds bringing colder air into the system as it tracks towards Lake of the Woods. Rain will likely mix with or change to snow Thursday into Thursday night, with some slushy accumulations possible.  The changeover to snow is still difficult to predict, since models differ on the strength and track of the main storm system, and the intensity of the associated precipitation. If the changeover to snow occurs earlier in the day Thursday as some models suggest, snowfall could be significant over portions of the RRV and SE MB. Whatever the case, it will be an important system to monitor over the next day or two. Stay tuned.

UPDATE 2: Winter storm warning in effect for southeast Manitoba, including Steinbach, Whiteshell and Sprague regions. 10-20 cm of snow possible Thursday into Thursday night with up to 30 cm possible in Sprague region.  Winter storm warnings in effect for northeast ND including Grand Forks, as well as northwest Minnesota for possible 6-12" of snow. 

UPDATE 1:  NWS Grand Forks has issued a winter storm watch for northeast ND and northwest Minnesota up to the Canadian border for potential of 6" (15 cm) or more of snow Thursday into Thursday night. Special weather statement issued for the Red River valley and southeast Manitoba for potential early snowfall. A special weather statement is in effect for Kenora and Red Lake for possible 5-10 cm of snow or more Thursday night into Friday.

Wild winds whip wildfires across southern MB.. moisture desperately needed

Winnipeg firefighters battle brush fire
off Loudon Rd in Charleswood
Tuesday Oct 2 2012
Strong southerly winds gusting up to 85 km/h in Winnipeg whipped several wild fires today across southern Manitoba, including two in Charleswood.  A grass fire developed off Charleswood Rd south of Wilkes Ave late Tuesday morning, before a larger brush fire flared up off Loudon Rd, also south of Wilkes around the noon hour. The strong south winds blew heavy smoke across Wilkes Ave into Tuxedo and SW Winnipeg.  The fires were eventually controlled by Winnipeg firefighters, who had to truck water in to fight the blazes.  Several other wildfires erupted across southern MB Tuesday, the most serious near Vita MB in the southeast part of the province. That fire destroyed 3 homes and a bridge, and led to a temporary evacuation of the entire town of 300 inhabitants before residents were allowed back after winds shifted into the west.

Extremely dry conditions over the past month, together with low humidity have left tinder dry conditions across southern MB, creating dangerous fire conditions when strong winds develop.  Significant moisture is desperately needed across southern MB, and there is a potential storm system brewing late Wednesday into Thursday that may bring the most significant precipitation over the Red River Valley and SE Manitoba in several weeks. Stay tuned..        

Monday, October 01, 2012

One last warm blast Tuesday.. then turning sharply colder and unsettled Wednesday through the rest of the week..

It's going to be an interesting week of weather coming up over southern MB as a significant pattern change evolves by mid week.  A intensifying low pressure system over southern Saskatchewan will track through central Manitoba Tuesday, bringing a strong southerly flow of warmer air over southern MB. Southerly winds will gust to 60 or 70 km/h over the Red River valley Tuesday including Winnipeg, which combined with the very dry conditions and low humidities will make for dangerous fire conditions. The gusty south winds will draw up warmer air with afternoon highs in the low to mid 20s.. some 10C above normal for this time of year. But that will be the end of 20C temperatures for awhile.. possibly the rest of the year. A sharp cold front will push through Wednesday morning with northerly winds bringing in much colder air into southern MB. Temperatures will struggle in the low teens Wednesday, falling into the single digits by evening along with a chance of some rain.  Temperatures will remain in the single digits for highs Thursday into Thanksgiving weekend, with even a chance of some rain or wet snow over portions of the RRV Thursday into Friday morning.  Enjoy the warm day Tuesday.. big changes are on the way this week!

September 2012 finishes as 2nd driest September in 140 years.. Above normal streak extends to 15 months..

September 2012 will enter the record books as the 2nd driest September ever recorded in Winnipeg since records began in 1872. The monthly total of only 4.0 mm was less than 5% of normal for September (average = 52 mm) and was second driest only to September 1948 at 1.3 mm. The dry weather has persisted for 6 weeks now, with the last appreciable rainfall back on August 15th when 9 mm was recorded at YWG airport. The dry weather comes on the heels of a dry summer that saw only about half our normal rainfall. This has left soil moisture conditions bone dry, and significant rainfall of 50 mm or more is desperately needed to replenish soil moisture levels. September was Winnipeg's 4th consecutive drier than normal month, with rainfall deficit now standing at 153 mm since June 1st.

Top 5 driest Septembers on record (Winnipeg) - since 1872 

1. 1948 ..... 1.3 mm
2. 2012 ..... 4.0 mm
3. 1938 ..... 6.1 mm
4. 1897 ..... 8.6 mm
5. 1976 ..... 9.9 mm

September  2012 also finished slightly above normal thanks to some warm weather at month's end that boosted the monthly average to 12.6C, or about 0.3C above normal. That extends the monthly above normal streak to an unprecedented 15 straight months in Winnipeg, going back to June 2011.

Saturday, September 29, 2012

Stellar weekend to wrap up September..

It will be a beautiful weekend to wrap up September with mainly sunny skies and warm temperatures. Today will be a spectacular fall day with a southerly breeze and clear blue skies allowing temperatures to soar into the upper 20s this afternoon across the Red River valley, with highs of 27C expected in Winnipeg. A great day to enjoy the fall colours. Sunday will see a continuation of the warm weather, although it will be a few degrees cooler as a frontal trough crosses the Red River valley by midday, with some patchy clouds and winds shifting into the northwest. Still, temperatures in the low 20s are expected to close out the month. Enjoy the warm weather while it lasts however because this may be the last mid 20 temperatures we see this season. Significantly colder weather is expected by mid week with high temperatures only in the single digits expected by Wednesday or Thursday.

Monday, September 24, 2012

Dry finish to a dry month.. 2nd driest September on record possible

September 2012 will be ending on a sunny and dry note over the Red River valley and southern Manitoba.. a fitting end to what has been an exceptionally dry month. As of today, only 4 mm of rain has fallen at Winnipeg airport this month, with no precipitation forecast all this week through the end of the month.  If so, September will end up as the 2nd driest September on record in Winnipeg since records began 140 years ago in 1872. Only September 1948 will have been drier in the city at 1.3 mm for the month.

Top 5 driest Septembers on record (Winnipeg) - since 1872

1.  1948 ..... 1.3 mm
2.  2012 ..... 4.0 mm  (through the 24th)
3.  1938 ..... 6.1 mm
4.  1897 ..... 8.6 mm
5.  1976 ..... 9.9 mm

Rainfall past 30 days across Prairies.
Note large area with little
or no rain over the past month. 
Normal September rainfall is around 52 mm, so this month's rainfall has been less than 10% of normal. The last appreciable rainfall in Winnipeg was back on August 15th when 9 mm was recorded. Since then, only about 5 mm of rain has fallen in the past 6 weeks, coming off a dry summer that saw a little more than half our normal summer rainfall.  This is resulting in very low soil moisture levels, with cracking and shifting clay causing problems with city watermains and house foundations.  The dry soil conditions will also become an increasing concern for agriculture and forestry interests if adequate moisture is not received over the winter months.  Why has it been so dry?  Simply put, the jet stream has been steering storm systems away from the southern Prairies over the past month, with storms systems tracking mainly across northern regions. This has been mainly due to a persistent upper ridge over western Canada that has effectively blocked moisture laden systems off the Pacific from tracking across the southern Prairies (see image of rainfall over past 30 days across Prairies)  A pattern change will be needed in October to bring some precipitation bearing systems across southern Manitoba, but past history suggests that may not happen. Of the top 5 driest Septembers in Winnipeg, all but one were followed by much drier than normal Octobers.

Sunday, September 23, 2012

Record cold September morning across RRV and southern MB..

7 am temperatures across southern MB
Sept 23 2012
Clear skies, light winds and a cool airmass over southern Manitoba brought a widespread freeze over southern Manitoba this morning, with record low temperatures set at many locations. In Winnipeg, temperatures fell to a low of -7.1C at YWG airport, beating the previous record low for Sept 23rd of -6.1C set way back in 1879.  In fact, it was the coldest September temperature in Winnipeg in almost 50 years, since a -7.2C reading on Sept 26 1965 (we had a -7.0C reading on Sep 28 2002)  Even the normally balmier downtown core registered its first fall freeze with a low of 0.0C, about 2 weeks earlier than usual (normal first freeze date is Oct 5th downtown)   Even colder temperatures were registered elsewhere in southern Manitoba including a frigid -8.5C in Emerson and Fisher Branch, unusually cold for this time of year.  It's possible that the very dry soil conditions over the past month helped to accelerate heat loss from the ground, allowing for the very cold temperatures to develop.

Record lows across southern MB today.. 

Site .....................................  New record ....... Old record....  Year .... Records began

Brandon airport        -6.7     -6.7(tie) 1976    1890
Fisher Branch          -8.5     -5.5      2001    1977
Gretna                 -6.3     -2.8      1995    1955
Pilot Mound            -5.0     -5.2      1976    1938
Pinawa                 -4.3     -2.5      1989    1964
Sprague                -6.9     -6.0      1989    1915
Winnipeg               -7.1     -6.1      1879    1872

It will be a nice turnaround today though as sunny skies and light southwest winds send temperatures back into the mid teens this afternoon. Normal highs for this time of year are 16C, with normal lows of +4C.

Thursday, September 20, 2012

Cold front Friday to usher in cooler airmass for first weekend of fall..

Things have cooled off over southern Manitoba this week as a northwest flow of cool air persists over the eastern Prairies. And things will get even cooler Friday into Saturday as a cold front pushes in from the north, ushering in the coolest airmass of the season so far, just in time for the first day of fall Saturday. The cold front is expected to push through Winnipeg from the north around midday Friday, accompanied by a few showers. Behind the front, northerly winds will increase gusting to 60 km/h, ushering in cooler air from the north with temperatures dropping into the single digits. In addition, the cool air over the 15C lake waters will generate bands of lake effect showers off Lake Winnipeg, and Lake Manitoba. Below normal temperatures are expected into the weekend before a gradual warming trend next week.    

Monday, September 17, 2012

Dry spell continues.. only 2 mm of rain in Winnipeg since mid August

Rainfall over past 30 days across Prairies.
Note large area with little or no rain
from southern AB to southern MB
It's been an exceptionally dry 4 weeks over the Red River valley with very little in the way of storms systems affecting southern Manitoba, or much of the southern Prairies for that matter (see top image left). In Winnipeg, only 2 mm of rain has fallen since August 15th, with only 4 days of minimal precipitation in that time. (NOTE: Winnipeg airport has recorded some false precipitation readings since August 15th, resulting in slightly higher amounts than actually have fallen) 

Rainfall in Winnipeg over past 30 days.
Moisture deficits are running over
50 mm now.
Normally we should see about 52 mm of rainfall in September, but we're far from that pace, and the prospects for significant rain in the next week or so are not promising. A system dropping from the Interlake may give us some rain overnight Tuesday into Wednesday morning, but at this point, amounts only look to be in the 2-5 mm range for Winnipeg, far from enough to ease soil moisture concerns. Other than that, things look persistently dry through the next week or so. Soil moisture levels are getting very low across the RRV, after a dry summer that saw only about half the normal rainfall.  This will become more of a concern for farmers if adequate moisture is not received by winter freeze up.   

Friday, September 14, 2012

2012 growing season ends with frost over much of southern MB..

7 am temperatures - southern MB
Sept 14 2012
Temperatures dropped below freezing across much of southern Manitoba early this morning, including at the Winnipeg airport with a low of -1.0C.  This marks the end of the official growing season for 2012 (as measured at YWG airport), which lasted 106 days since the last spring frost on May 30th (low of -0.1C). This is actually a bit shorter than normal for Winnipeg's average growing season, which generally runs 121 days between the average last spring frost of May 23nd and the first fall frost of  Sept 22nd.   However, this year's growing season length is a bit misleading. There were only 2 days of light frost in May, with low of -0.7C on the 16th and -0.1C on the 30th. The last hard freeze (temperature below -2C) was back on April 26th with a low of -7.0C.  Using this date gives a growing season length of 140 days, which is more representative of the ideal conditions experienced this year. Farmers were able to get in a crop much earlier than usual thanks to a record warm March, with warm conditions persisting through the summer along with adequate rainfall. The result was a record crop for many across southern Manitoba this year.  

And although frost was fairly widespread over the RRV this morning, downtown Winnipeg escaped frost with a low of only +5.0C at the Forks. Downtown Winnipeg has a much longer growing season than the airport, due to the urban heat island effect that keeps night time temperatures warmer than areas near and outside the perimeter. The average first fall frost downtown is Oct 5th, while the last spring frost is May 4th giving an average growing season of 159 days downtown, or 38 days longer than the airport (121 days). For most areas of the city, the length of the growing season lies somewhere between downtown and airport values. At my site in Charleswood, a low of +0.1C was recorded with some light frost.

Wednesday, September 12, 2012

Warmer weather for end of week before cooldown Sunday into next week

After some windy and seasonably cool weather, temperatures will be on the upswing again for Friday and Saturday over southern Manitoba as southerly winds spread warmer air back into the area.  Temperatures in the teens Thursday will warm into the mid 20s Friday and upper 20s Saturday as brisk southerly winds develop.  That however will be the last of warm weather for awhile as a cold front pushes through on Sunday, bringing significantly cooler air into southern MB for Sunday through much of next week.  High temperatures next week will only be in the low to mid teens, along with a possibility of some morning frost depending on cloud cover and wind conditions.

Some scattered showers may accompany the cooler weather next week as well, but overall there doesn't appear to be much in the way of significant rainfall over the next week or so.  Things are becoming quite dry over southern MB with only 2 mm of rain in Winnipeg over the past 4 weeks, following a much drier than normal summer, the 10th driest on record in Winnipeg.  

Saturday, September 08, 2012

Blustery Saturday to give way to pleasant Sunday

It was a blustery start to the weekend over the Red River valley with strong northerly winds gusting over 70 km/h at times along with mainly cloudy skies and temperatures in the upper teens (a peak gust of 80 km/h recorded at the Brady landfill weather station)  The winds were associated with a strong push of cool air from northern Manitoba flooding southward. Winds will be diminishing this evening becoming light overnight along with clearing skies that will allow temperatures to drop into the single digits over much of southern MB, including Winnipeg where a low of +4C is forecast.  After a chilly start, Sunday will be a much more pleasant day with bright sunny skies, lighter winds and afternoon temperatures rebounding into the low 20s.  Conditions will be even warmer Monday as gusty south winds to 50 km/h push in a warm airmass with temperatures rising into the upper 20s along with sunny skies.      

Monday, September 03, 2012

Cooling off this week as kids head back to school

The traditional last weekend of summer ended up on a sunny and warm note over Winnipeg with temperatures rising to 29C for Labour Day Monday .. some 8C above normal for early September. But the summerlike temperatures will be on their way out this week as a large storm system over the northern Prairies pushes cooler air towards southern Manitoba over the next few days. Tuesday will see a mix of sun and cloud with highs of 24C, about 5C cooler than today but still seasonably warm for early September. Tuesday night, a cold front will track across southern Manitoba bringing a chance of showers, along with a push of cooler air for Wednesday and the rest of the week. Temperatures will be noticeably cooler as the kids head back to school, with autumn like highs in the upper teens to near 20C through Friday. Sunny and warmer conditions are forecast for the upcoming weekend.