Winnipeg, and many other regions in the Red River Valley, received the most significant rainfall so far this year yesterday as an area of moderate rain moved into the province from North Dakota and stalled out for much of the day. Rainfall totals in most places were near 20–30mm with slightly higher amounts in the southwestern Red River Valley:
| Location | Rainfall Total (mm) |
|---|---|
| Letellier | 41 |
| Altona | 37.6 |
| Morris | 34.2 |
| Winkler | 29.8 |
| Steinbach | 27.8 |
| Winnipeg | 24 |
| Dugald | 22 |
| Elm Creek | 12.6 |
| Portage la Prairie | 9.6 |
The Altona/Letellier areas seem to be the winners for total rainfall with almost 1.5” of rain in total. Unfortunately for farmers who are still working at getting seed into the ground, there won’t be much of a reprieve from wet weather before more rain is on the way as another major low pressure system is hot on the heels of the previous one and is set to bring a whole host of unsettled, pleasant and stormy weather for the May long weekend.
Pleasant Friday, then Downhill
Today will be a very pleasant day across the Red River Valley with mainly sunny skies and temperatures climbing into the high teens under partly cloudy skies. Winds will be fairly light out of the northwest. Friday night will see temperatures drop to around 7°C under clear skies. The nice weather won’t last too long, though, as a potent low pressure system moving into the Northern Plains of the United States tonight will result in cloud and some light rain spreading across Southern Manitoba early on Saturday. The heaviest rainfall will hold off until much later in the day, however, as this system will end up being strongly driven by convection.
The SPC[1] in the US currently has a slight risk of severe thunderstorms in their outlook for Saturday scrunched right up the Canadian border. Further north in our area, it looks like an initial shot of some showers associated with elevated convection will lift through the region early in the day. Temperatures will warm towards the 20°C mark with an increasing risk of showers or thunderstorms.
Later in the afternoon, best indications at this point are that an area of thunderstorms will initiate in North Dakota and push northeastwards through the Red River Valley. It looks like precipitation will most likely be showers or weak thunderstorms, however the outside chance exists that an isolated severe thunderstorm may be seen. A thunderstorm outlook later will be issued later today covering all of Southern Manitoba.
A few showers will be likely through the overnight hours as the temperature drops to 9°C or so.
Sunday will be the most significant precipitation day with rainfall intensifying through the morning into the afternoon. There’s some uncertainty as to where the western cut-off will be for the rain, but general consensus at this point is that the entirety of the Red River Valley will see rain on Sunday.[2] Total accumulations are hard to nail down at this point, but look to be in the 25–50mm range.
Things take an unwelcome turn on Sunday evening as colder air works its way into Southern Manitoba on the back-side of the system. Rain may become mixed with or switch over to snow as it begins tapering off. No significant snow accumulations are expected. Temperatures will drop off to around –3°C on Sunday night with winds gradually tapering off.
Holiday Monday A Cool Improvement
Looking ahead to the start of next week, it looks like Monday will mark the transition out of this active pattern we’ve been in. Sunny skies and exceptionally cool weather look to be on tap with highs struggling to get to even 10°C[3]. Conditions will improve over the subsequent days with drier weather and temperatures returning to the seasonal mark.
