Friday, February 25, 2011

Another cold night.. some moderation Sunday but generally colder than normal weather through start of March

Another cold night is on tap over southern Manitoba as a ridge of Arctic high pressure over the Dakotas maintains clear skies and below normal temperatures over the area. Temperatures will likely drop to the -30C mark once again over the Red River valley overnight into Saturday morning with south to southwest winds of 15 to 20 km/h producing wind chills near minus 40 overnight. On Saturday, temperatures will start to moderate but gusty south winds will make it feel uncomfortably cold in the Red River valley. A frontal trough will pass through Saturday night with clouds and some light snow, which will be followed by milder conditions Sunday with highs around -5c along with lighter winds. Colder weather will follow for Monday with some snow possible Monday night (1-3 cm possible for southern MB including Winnipeg) Below normal temperatures will continue through the first week of March with additional snow possible by the end of the week. Old Man Winter is hanging on tough this year!

Thursday, February 17, 2011

Snow and blowing snow moving into Red River valley

An intensifying storm system developing over North Dakota will track into Northwestern Ontario tonight. Snow is spreading eastward across Southern Manitoba this afternoon as this system approaches. 5 to 10 cm of snow is likely for most areas of Southern Manitoba before the snow tapers off from west to east overnight into Friday morning. In addition to the snow, strong northwest winds gusting up to 70 km/h will develop by evening on the back side of this system and the combination of the falling snow and strong winds will produce poor visibilities of less than 1 km in snow and blowing snow especially over open rural areas. Blizzard conditions may develop especially in the Red River Valley this evening if the strongest of the winds materialize. Conditions will improve on Friday as winds gradually subside.

Sunday, February 13, 2011

Mild week ahead.. Storm system threatens snow, colder temps for late week

Springlike weather will be moving over southern MB this week as a mild Pacific airmass spreads across the Prairies. We'll get a taste of that mild weather today as a westerly wind brings in above freezing temps into southern MB and the RRV with highs of +2 or +3C. A cold front however will push through this afternoon into this evening, bringing a few rainshowers that will change over to snow by late afternoon/evening as temperatures drop below freezing. Watch for icy conditions tonight as northerly winds bring in colder air and freeze up any standing water. Monday will see increasing southerly winds develop in the afternoon and evening, bringing temperatures back towards freezing. This will set the stage for very mild conditions Tuesday and Wednesday as the peak of the warm air spreads over southern MB. Temperatures will be climbing into the +2 to +5C range over Winnipeg/RRV with +7C readings possible over the traditionally warmer downslope areas from the eastern Riding Mtns through the western RRV (Dauphin to Portage and Morden)

Attention then turn to a potential storm system that may affect southern MB for the end of the week. Long range models are showing a storm system developing over the central Plains that will be moving into Minnesota by Friday. This system will be bringing increasing north winds and colder temperatures by Friday along with the potential for accumulating snow, possibly significant over the RRV. At this point, it's too early to be more specific, but it does pose our next threat for significant snowfall. Stay tuned.

Sunday, February 06, 2011

Winnipeg snowfall stats through January

The following is a summary of the winter snowfall so far in Winnipeg. Snowfall data is from my site in Charleswood, while past snowfall data previous to 2004 is from YWG airport and St Johns College.

Snowfall - October 2010 to January 2011 ………. 116.6 cm
Normal snowfall (October to January inclusive).... 69.3 cm

Normal snowfall for entire snowfall season ........ 110.6 cm

So already at the end of January, we have exceeded our normal snowfall for the entire snowfall season (technically from September to May, although snowfall in both September and May is rare).

This is the greatest October to January snowfall accumulation since October 1996 to January 1997 when 136.8 cm was recorded. However this is still nowhere near a record and not in the top 10 for Oct-Jan snowfall accumulations. The record was in 1955-56. From October 1955 to January 1956, Winnipeg Richardson Intl Airport received 183.3 cm and for the entire snowfall season there was 252.6 cm, our snowiest winter ever.

Top 12 Snowfalls October to January (cm)

.......Years......Oct-Jan... Entire Snowfall Season
1. 1955-56..... 183.3..... 252.6 cm
2. 1915-16..... 152.9..... 216.7
3. 1919-20..... 152.6..... 211.8
4. 1996-97..... 136.8..... 213.4
5. 1909-10..... 132.8..... 212.8
6. 1906-07..... 127.0..... 193.5
7. 1933-34..... 126.6..... 170.5
8. 1949-50..... 126.0..... 201.9
9. 1988-89..... 122.9..... 152.3
10. 1965-66..... 117.3..... 212.6
11. 1874-75..... 116.7..... 140.3
12. 2010-11..... 116.6......???

Top 12 Snowfall seasons (Sept-May)

.......Years..... Entire Season..... Oct-Jan
1. 1955-56...... 252.6 ............ 183.3 cm
2. 1915-16...... 216.7............. 152.9
3. 1996-97...... 213.4............. 136.8
4. 1909-10...... 212.8............. 132.6
5. 1965-66...... 212.6............. 117.3
6. 1919-20...... 211.8............. 152.6
7. 1949-50...... 201.9............. 126.0
8. 1893-94...... 194.3............. 101.3
9. 1906-07...... 193.5............. 127.0
10. 1935-36.... 184.3............... 93.8
11. 1995-96.... 183.0.............. 99.1
12. 1892-93.... 181.2............. 100.7

Snowfall records:

Winnipeg St Johns College: 1872-1938
Winnipeg Richardson Intl Airport: 1938-2007
Winnipeg Charleswood: 2004-present

Thursday, February 03, 2011

Risk of freezing rain overnight in Winnipeg/Red River valley

Temperatures finally climbed to the freezing mark today in Winnipeg, the first time since November 16th that the temperature did not stay below freezing. In fact, it was milder today in Winnipeg (0.0C) than in Brownsville Texas (-1C with freezing rain and sleet) Temperatures have dipped below freezing this evening but are expected to rise overnight as clouds and southwest winds increase ahead of the next batch of precipitation currently over central SK/MB. This batch of precipitation is falling in the form of rain and some wet snow, and will track into southern MB overnight. This will result in patchy freezing rain developing where surface temperatures remain below freezing. Even if temperatures climb above zero overnight, the light rain falling on cold surfaces will likely result in locally slippery conditions on untreated surfaces such as walkways and side roads, which could create problems for the morning commute. Luckily the temperature should remain above freezing Friday so any ice should quickly melt Friday morning. Saturday looks fairly tranquil before blustery and colder conditions move in Sunday with some snow and blowing snow.

UPDATE: 9 pm: Freezing rain warning issued for Winnipeg and Red River valley.