Thursday, 14 April 2016

March Brought Another Early Spring to Southern Manitoba

For the second year in a row and for the fourth time in the last seven years, March brought a very early spring to southern Manitoba.

The month started out cold with lows in the -20's on the first three days, but spring-like temperatures arrived just a couple days later and lasted the remainder of the month. In fact, after March 4 only four days failed to exceed the freezing mark in Winnipeg. In the end, the month averaged -2.0°C at Winnipeg Int'l Airport, 3.8°C above normal and the 12th warmest March on record since 1872.

Winnipeg on March 11
Temperatures early month were warmest where there was little to no snow cover. Extreme southwestern Manitoba and the Morden-Winkler area already reached double digit highs on March 5 and 6. After a brief cool down (which still featured warmer than normal temperatures), record warm temperatures spread throughout the remainder of southern Manitoba by March 10 and 11 with widespread double digit highs lasting until March 14. Winnipeg reached 12.2°C on March 12, breaking the old record of 9.7°C in 2012. A high of 13.1°C two days later narrowly missed the old record of 13.2°C set just last year. It was warmer to the south and west. Morden reached its highest temperature for so early in the year three times with record highs of 16.0°C on the 11th, 16.2°C on the 13th and 18.5°C on the 14th. The high of 18.5°C on the 14th broke the old record of 18.3°C set just last year. Prior to 2015, the old record for the day was 11.2°C in 2012. It is mind boggling to think a record could be broken by such a large margin two years in a row. This highlights how unusually early warm temperatures have been arriving in recent years.

In Brandon, four record highs were reached and one was tied during the warm spell. A high of 17.9°C on the 15th not only broke the daily record of 14.9°C in 2012 by a 3°C margin but was also the warmest temperature for so early in the year since 1890. Melita took top honours with a high of 20.5°C on March 14, the earliest high over 20°C on record in Manitoba. The previous earliest 20°C was on March 16, 2012 when several locations reached the low 20's.

Thanks to the warmth, everything was early this year in southern Manitoba. Migratory birds already arrived by early to mid March. Snow and ice melt were unusually early as well. The snow pack eroded from southwest to northeast with Brandon losing its snowpack by around March 10. Winnipeg's snow pack reached 0 cm by March 15, tied with 1995 and 2015 for 3rd earliest snow melt on record since 1955. River ice also disappeared by the end of March.

Comparing 2016 to 2013 around the same time in mid March in Winnipeg

The thunderstorm season also came to an early start. Isolated thunderstorm cells occurred late evening on March 7 in southeastern Manitoba and occurred as close to Winnipeg as Selkirk. Winnipeg's earliest recorded thunderstorm was on March 19, 2012, but no thunderstorms occurred in the city in March this year. Stronger thunderstorms pushed into southwestern Manitoba from North Dakota late evening on March 14 and overnight on March 15. Pea to dime size hail was reported in the Killarney area along with a decent lightning show. The thunderstorms were associated with a strong system moving up from the US. Heavy rains spread across the Red River Valley in the morning on March 15. Generally 15-20 mm of rain fell in Winnipeg for the day. 15.7 mm fell at the airport, breaking the old record of 11.4 mm in 1946 for the day. The heavy early season rains caused overland flooding because the ground was still frozen. A state of emergency was issued in one municipality southeast of Winnipeg due to flooding concerns. Fields were underwater.

The system which moved into Ontario pumped ample moisture westward back into Manitoba late March 16 into early March 17. Heavy snow spread from east to west. Generally 5-10 cm fell from Brandon eastward with 10-15 cm close to the Ontario border (14 cm in Pinawa). In Winnipeg, 8-10 cm fell. The snow was very wet and stuck onto anything it landed on making for a spectacular winter scene in the morning as seen in the photos below that I took.

Generally mild conditions continued through the remainder of the month with a couple more double digit days at the end of the month.

Similar to February, warm temperatures in March were increasingly extreme as you went westward and southward. Average temperatures and ranking for March are provided below:

Brandon MB ................. -0.6°C ....... 6th warmest
Regina SK ....................    0.3°C ....... 5th warmest
Calgary AB ..................    3.3°C ....... 3rd warmest
Grand Forks ND ..........    2.2°C ....... 2nd warmest
Fargo ND ....................    3.6°C ........ 3rd warmest

Some milestones were reached. In Regina, a high of 17.3°C on March 5 was the earliest high over 17°C on record since 1884. It broke the old record by two weeks (old record March 18, 1910). In addition, 5 record highs were broken during the month, including a 4-day streak of record highs from the 10th to 13th. In Bismarck ND, temperatures reached 24°C on March 6, the earliest it has been that warm on record. The warmth extended into the Yukon as well with Whitehorse reaching an all-time March high twice with highs of 12.7°C on the 29th and 16.8°C on the 31st. These broke the old all-time March high record of 11.7°C in 1979. The high of 16.8°C on the 31st was three weeks earlier than Whitehorse has seen before. It was so warm out west that there were reports of budding trees in late March and farmers seeding their fields in mid March in southern Alberta, a couple weeks earlier than ever seen before.