#10, #9 & #8 - Top 10 Weather Stories of 2014 in The Winnipeg Area

#10 - July in May: Record Heat & Numerous Thunderstorms Late May 

     After an April-like first 2/3^rds of May, Mother Nature had a dramatic mood swing on May 22 when the weather abruptly became July-like for the remainder of the month. Daytime highs exceeded 20°C on all but one day and exceeded 25°C on 7 days. 2 super-hot days exceeded 32°C, the most 32°C days in May since 1995 when we also had 2 days. Just 10 days after we saw snow we reached 33.3°C on May 24, breaking the old record of 32.7°C in 1980. It was the hottest day in May since a high of 33.7°C on May 30, 1995 and the first 30°C day in May since 2007. Surprisingly, it was also the hottest day of 2014! The last time our hottest day of the year was outside the summer months of June, July or August was in 2004 with a high of 31.2°C on September 19. The last time the hottest day of the year was in May was in 1994 with a high of 31.8°C on May 18.

     With the heat came thunderstorms. Multiple rounds of thunderstorms occurred throughout southern Manitoba May 24^th to 29^th. After a record hot day in the low to mid 30’s May 24^th, thunderstorms formed in the afternoon in the Winnipeg area (see radar loop). Crashing thunder and heavy downpours occurred with generally 5-15 mm in the city. 27 mm fell at the St Adolphe MAFRI station to the south.

     A trailing line of thunderstorms developed from Emerson to Steinbach close to noon on May 25 and dumped impressive rainfall totals in a short period of time. Generally 20-40 mm of rain fell around Steinbach (see radar loop). According to SteinbachOnline, creeks overflowed and several streets flooded, making travel difficult. 

May 29 looking northwest from TCH near Carberry

     Strong thunderstorms moved into southwestern Manitoba May 26, binging damaging winds, hail and 29 mm of rain in Melita.  

     Trailing thunderstorms again became a problem May 29, this time in southwestern Manitoba. Three rounds of thunderstorms hit the area in the morning and evening, dumping generally 30-40 mm of rain from Melita to Brandon. Locally higher amounts fell, such as in Swan Valley where 51 mm was recorded. According to the Brandon Sun, flooding forced the closure of highway 10 near the town. In Brandon, some streets flooded, there were some power outages and branches were taken down by wind gusts of 70-80 km/h. A photo gallery of the storms in southwestern Manitoba can be seen here.

#9 -  Mid-Fall Warmth & Very Dry Conditions

     After an extended period of cooler conditions and persistent northwesterlies in early October, things turned around mid-month when above normal conditions became dominant.  

     All but two days exceeded 10°C from October 10 to 26. The average high during this 17-day period was 15.5°C, more than 5°C above normal for the period. Two days reached 20°C; October 15 and 24. In fact, a high of 20.6°C on October 24 had not been reached that late in the season since 1990. Despite the above normal conditions, no record daily highs were broken during the warm spell. In the end, the month only averaged 6.7°C, 1.6°C above normal and tied 42^nd warmest October since 1872. Cool downs early and late month prevented October from finishing very warm overall.

     The main story of mid fall was the lack of precipitation. No major systems heavily impacted the Red River Valley in October. Only 4.9 mm of precipitation fell at the airport in October, the 3^rd driest October on record since 1872. All of this precipitation accumulation fell as rain, the 13^th least rainy October.

Table: Top 10 driest Octobers since 1872 in Winnipeg.

Rank	Precipitation	Year (s)
1	2.5 mm	1976
2	2.8 mm	1992
3	4.9 mm	2014
4	5.3 mm	1906, 1920, 1974
7	5.8 mm	1964
8	6.9 mm	1874
9	8.1 mm	1939
10	8.4 mm	1895

Nov 11 after the first snowfall of the season

     Other parts of the city were not as dry in October. Southern parts of the city saw closer to 10 mm of rainfall. Even a couple thunderstorm events occurred in southern and eastern parts of the city October 12 and 22. As for snowfall, only trace amounts fell in the city early and late month. 

 

     Thanks to the warm temperatures not only in late September but also in October, the first frost of the season was delayed. The airport saw its first frost on October 4, tied 12^th latest on record in Winnipeg since 1872 and the latest since 2005. The 1981-2010 normal is September 24 for the airport. Downtown did not get its first freeze until October 30, 3-4 weeks later than usual. The mild conditions continued entering into November. As a result, we did not get our first snowfall accumulation until November 10 (~1 cm), tying 14^th latest since 1872. The 1981-2010 normal is October 18. The latest was November 21, 1963.

     In the end, fall 2014 ended at about 18^th driest since 1872 with around 60 mm of precipitation. The lack of precipitation was mainly in October. September and November were only slightly drier than normal.

#8 - January In November 

 

     Winter cold came early this year in southern Manitoba. The ‘‘gates to the arctic’’ opened up in mid November as a deep trough formed over central and eastern North America following a strong typhoon in the western Pacific. An unseasonably prolonged cold snap resulted, bringing well below normal temperatures from mid November to early December. Temperatures dropped below -20°C six times in November, above the normal of 3 days and the most since 1996 when there were 13 days below -20°C. In addition, a minimum of -29.6°C on November 26 was the coldest temperature in November since 1996. A daily high of -19.3°C occurred on both Nov 26 and 30, the coldest highs in November since 1985.

     In the end, November averaged -8.8°C, 4.2°C below normal and the 22^nd coldest November since 1872. It was also the coldest since 1996 and the 9^th coldest in the last century.

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List of sources here