Another unsettled weekend ahead.. showers and thunderstorms likely, locally heavy at times

Another weekend, another shot of unsettled weather coming up for southern Manitoba as a warmer and more humid airmass spreads over the eastern Prairies, while periodic weather systems trigger showers and thunderstorms Friday through Sunday. Much like last weekend, this upcoming weekend won't be a total washout with sunny, dry stretches at times. However, occasional showers and thunderstorms are likely each day, especially at night with the potential for some severe thunderstorms.. along with locally heavy rainfall. This will not be welcome news for those hoping to dry out from the wet weather over the past couple of weeks which has produced over a month's worth of rain in Winnipeg within a week. Cooler weather is expected to move in next week behind this unsettled weather pattern. 

Unsettled weekend ahead.. wet Sunday likely for Dads and runners..

After some dry and pleasant weather this week, it looks like things will be getting more unsettled this weekend over Winnipeg and the Red River valley as a pair of weather systems affect the region. The first wave of precipitation is expected to move in Friday night into Saturday morning ahead of a warm front pushing up from North Dakota, possibly giving 5-10 mm to Winnipeg by Saturday afternoon (although some models are showing much less.. only a couple mm with the first wave). We'll get a bit of a break Saturday afternoon before another wave of rain moves in Saturday night into Sunday as a more potent system intensifies over northern Minnesota. That will likely bring steadier and heavier rain for Father’s Day (and the Manitoba Marathon) with 15-25 mm possible for Winnipeg. Not the best timing on the weekend, but the rain will be beneficial for farmers in the Red River valley, and most marathon runners would rather run in the rain than in the heat. Rain is expected to taper off later Sunday into Sunday night as the system pulls east.

Warm finish to May salvages slow start to spring..

Temperature departure from normal
for last week of May shows core of warmth
over northern Plains/southern MB (finally!)   

After a dreadfully long cold winter and slow start to spring, persistent warm weather finally returned to southern Manitoba for the end of May, with temperatures some 5-10C above normal over the last week of the month. The pattern change to warm weather was long overdue and finally signalled a break in the below normal temperature pattern that had persisted since last fall. Thanks to the late month warmth, the month finished with an average temperature of 11.3C, just 0.3C shy of normal for May (1981-2010 average of 11.6C)

The warm weather included the season's first 30C weather in Winnipeg, with highs of 33.3C on May 24th (record high) and 32.7C on May 29th. . These marked the hottest May days in Winnipeg since 1995 and the first time since 1995 that we've seen two or more 30C days in May. Amazingly, this hot weather came only 10 days after a trace of snow was recorded on the 14th, the only snow of the month. Rainfall for the month was only 42 mm at YWG airport.. about 75% of the normal May rainfall of 54 mm. All in all, a summer like end to May, much appreciated by long suffering residents of southern Manitoba!

For more details on May statistics, see JJ's Winnipeg Weather blog May summary.