Thursday, January 30, 2014

Cold but stable pattern into first part of February

Some good news and bad news on the weather front. The bad news is that the below normal temperature pattern of the past two months is expected to continue into February with no signs of any major pattern change towards milder weather in the foreseeable future. The good news is that the volatile pattern of frequent clipper systems and snowfall across southern MB over the past two weeks will be ending for the next little while, as a drier more stable pattern takes hold across the Prairies with generally high pressure systems dominating. This will be welcome news to snow weary Manitobans who have had to endure frequent rounds of nuisance snowfalls over the latter half of January, along with strong winds, blowing and drifting snow, and wild temperature swings. This will also be welcome news to overworked road crews who have had a tough time keeping area roads and highways cleared.  The frequent bouts of bad winter weather has led to numerous accidents over southern MB, with MPI reporting well above normal accident claims for both December and January. The upcoming stable pattern should help bring accident claims down over the next little while. (as long as motorists drive safely and for the conditions!)

As for January 2014, it will end up with a mean temperature of around -20C in Winnipeg.. about 3.5C below normal for January (1981-2010 average of -16.4C), the coldest January in Winnipeg in 10 years (January 2004 average -21.7C)   As cold as January seemed this year, it won't even rank in the top 40 coldest Januarys in the city since records began in 1873, showing how cold Januarys can get in southern MB, and also how spoiled we've become with the warmer winters of the past decade.  The normal for January in Winnipeg is now -16.4C (1981-2010 average), some 3C warmer than 30 years ago.  However, if we look at the combined period of December-January, then the average temperature of -20.5C this winter in Winnipeg makes it the coldest Dec-Jan period since 1949-50 (average of -21.2C) and the second coldest in the past 120 years.  So if you're feeling that it's been awhile since you've experienced a winter this cold through the end of January, you know why.

Top 15 coldest December-January periods in Winnipeg (since 1872)

1.    -23.2C   1886-87
2.    -22.4C   1884-85
3.    -22.2C   1887-88
4.    -22.0C   1882-83, 1879-80, 1876-77
7.    -21.6C   1872-73
8.    -21.5C   1893-94, 1874-75
10.  -21.4C   1883-84
11.  -21.3C   1880-81
12.  -21.2C   1949-50  (coldest of the 20th century)
13.  -21.0C   1892-93
14.  -20.5C   2013-14
15.  -20.4C   1906-07   

As for what is in store for February, cold weather will likely continue much of the month based on past climate trends. Of the 25 Januarys in Winnipeg with a mean temperature of -20 to -22C, 76% were followed by colder than normal Februarys, while only 16% were warmer than normal. 8% were near normal. Note however that the most recent cold January, January 2004, was followed by a milder than normal February, so there is some hope that February can turn around, although admittedly the odds are against us. We can only hope Mother Nature takes some pity on us for her harsh start to winter this year.  

Link: How cold has this January been in the US?  (from Chris Burt, WeatherUnderground)

Wednesday, January 22, 2014

Another clipper on the way.. snow and blowing snow by Thursday evening. Turning colder again for weekend..

In what is becoming an all too familiar pattern this winter, another clipper system from western Canada will be tracking across Manitoba tomorrow, bringing increasing winds, snow, briefly milder temperatures and then another cold outbreak in its wake. In the short term, the clipper system will be spreading an area of snow across southern Manitoba Thursday, pushing into Winnipeg and the Red River valley by mid afternoon to early evening from the northwest.  Winds will be increasing out of the south through the day, with gusts to 60 or 70 km/h by evening which combined with the falling snow, will result in poor visibilities in blowing and drifting snow, especially Thursday evening. About 2 to 5 cm of snow is expected to fall by the time the snow tapers off around midnight, with temperatures continuing to climb Thursday night to about -5C by Friday morning. Friday will be a milder day with high temperatures near -3C before colder air moves in by evening. Saturday will see quiet seasonable weather before another clipper tracks through southwest Manitoba by Saturday night, bringing additional snow. This system will be followed by another surge of bitterly cold air Sunday into Monday with daytime temperatures in the minus 20s and brisk north winds giving wind chills in the minus 40s. Cold conditions will persist into the middle of next week before milder weather returns by the end of the week.  

Monday, January 06, 2014

Brutal wind chills easing.. relief from Arctic conditions on the way this week

The forecast is looking up for Winnipeg and
southern Manitoba. Relief from Arctic weather
is finally on the way later this week
It's been a frigid weekend over southern Manitoba as a bitterly cold Arctic airmass (aka "polar vortex") moved across the southern Prairies accompanied by brisk northwest winds of 20 to 30 km/h. The result was severe windchills in the minus 40 to minus 50 range, with Winnipeg recording a -51 wind chill reading at 8 am Sunday morning (-37C with a 20 km/h wind)   The high Sunday was only -30.2C, the first sub -30C high in Winnipeg in 10 years (high of -30.8C on Jan 30 2004)   The good news is that the brutal conditions are finally easing tonight as winds drop off and temperatures moderate. Although it will remain cold for a couple more days, conditions will be less severe than the past few days.  More significant relief from the cold is expected Thursday into the weekend as temperatures finally climb to above normal values for at least 5 days.. a much welcome respite from what has been an exceptionally cold 4 weeks. Since Dec 5th, Winnipeg has seen only 3 days above normal.. with an average temperature some 7.5C below normal over the past month. The relentless cold is causing numerous problems in Winnipeg with frequent water main breaks, terrible road conditions due to icy rutted roads, and many disabled vehicles.  Crane Towing reported that today (Jan 5th) was their busiest day in 40 years of business based on call volumes for stranded motorists, and MPI (Manitoba's auto insurance provider) stated that the 16,700 accident claims in December was the worst month for accidents in at least 15 years. Yes, it's been a long, cold winter.. and it's only early January! The upcoming warmup will be a welcome and much needed break for winter weary Winnipeggers.  

Thursday, January 02, 2014

Clipper system to bring in snow and milder temperatures Friday.. but turning frigid again for weekend. Brutal windchills Sunday into Tuesday..

The brutal cold snap which has been locked over southern Manitoba since last weekend will ease for one day Friday as an Alberta clipper system tracks into North Dakota. This system will spread some snow across southern Manitoba tonight with 2 to 5 cm possible by Friday morning, especially north of Winnipeg. On Friday snow will intensify with 5 to 10 cm possible across a wide swath of southern MB including Winnipeg. Some areas such as around the Riding Mountains and Whiteshell may even see 15 cm by the time the snow tapers off Friday evening.  In addition the system will be bringing in gusty south winds overnight and into Friday morning that will give blowing and drifting snow, with poor visibilities in open areas. Highway conditions will not be ideal Friday morning so be prepared to take some extra time to get your destination if travelling. The good news is that temperatures will finally moderate to above average values Friday afternoon with highs near -10C in Winnipeg and -5C along the US border. Unfortunately, the respite will be short lived as winds shift into the north behind the clipper system Friday evening and bring a return of Arctic air across southern MB for the weekend into next week. Gusty north winds Friday night and falling tempertaures will result in blowing snow and poor visibilities across the Red River valley, especially towards the US border.

GDPS model showing -35C
cold core at 850 mb over
southern MB Sunday
Frigid air will return for the weekend, and in fact, conditions look even worse than the past week as northwest winds will be increasing out of the northwest to 30 km/h with gusts to 50 by Sunday and Monday.. combining with -30C temperatures to produce wind chills in the minus 45 to minus 50 range. As a result, this next Arctic outbreak will feel even colder than the past week when winds have been relatively light.. so be prepared for brutal wind chills this weekend into early next week.  Frigid conditions will continue much of next week, although long range models are finally hinting at the Arctic pattern breaking down later in the week into next weekend with milder conditions moving in across the Prairies. Let's hope they're right!      

Wednesday, January 01, 2014

December 2013 second coldest in 120 years in Winnipeg.. 6th coldest on record

Even hearty Winnipeggers had
enough of the cold in December
(image - Winnipeg Free Press)   
The stats are in.. and the relentless cold of December 2013 helped make it one of the coldest Decembers on record in Winnipeg. The average temperature for the month (as recorded at Winnipeg airport) was a frosty -20.9C.. over 7C below the normal December average of -13.5C (1981-2010 average)   It was the coldest December in Winnipeg since 2000 which was the 3rd coldest December on record at -22.0C.  Other than that, you'd have to go back 120 years to December 1893 to find a colder December in the city (-21.4C)

Coldest Decembers on record in Winnipeg (since 1872)

   YEAR .....  Average temp

1.  1879 ....... -26.0C    
2.  1872 ....... -22.6C
3.  2000 ....... -22.0C
4.  1876 ......  -21.8C
5.  1893 .....   -21.4C
6.  2013 .....   -20.9C

(1981-2010 Dec average .... -13.5C) 

Winnipeg Dec 2013 temperature graph
Mild days were few and far between 
After a few days of relatively mild weather to start the month, the weather turned sharply colder by the 5th after a storm system tracked across southern Manitoba bringing about 15-20 cm of snow to Winnipeg and 25 cm across parts of southern Manitoba. That would usher in a 10 day spell of below normal temperatures, including a record cold -37.3C reading on the 15th. After a brief warmup on the 16th, temperatures dropped below normal again until Christmas holidays which were relatively mild. The Yuletide respite however was replaced by a month end cold spell that sent temperatures plummeting to -37.9C on the 31st.. the coldest December reading in Winnipeg since 1933. 

Snowfall for the month (as measured at my site in Charleswood) totalled 40 cm for the month, with 2 main snowfalls dumping 15 cm on the 4th, and 13 cm on the 26th-27th.  Seasonal snowfall to the end of December was 66.6 cm, compared to a normal 51 cm by Jan 1st.  All in all, a long cold month that felt more like January than December.