This week will start off on the cool side as a brisk northerly flow builds in behind this weekend’s Colorado Low. Temperatures on Monday will be downright chilly for mid-May.
Cool weather will dominate southern Manitoba on Monday
Monday
We’ll see skies gradually clear today as the system that brought us rain (and snow) this weekend departs. It will remain very chilly though, as temperatures barely climb into positive values. Daytime highs will only make it into the low to mid single digits, which should hopefully be enough to melt a good amount of the snow that fell. Winds will be northerly at 40 km/h gusting to 60 km/h, but will taper off throughout the day as the system pushes further off to the east.
Tuesday
Tuesday will remain on the cool side, but should be a fairly pleasant day (at least relative to the weekend!). High pressure will build into the region behind the weekend’s low pressure system, bringing much calmer conditions. High temperatures will climb into the teens under mainly sunny skies and light winds.
Wednesday
Wednesday will be quite nice as temperatures climb into the upper teens under mainly sunny skies. Winds will be relatively light and from the north-west, making for another pleasant day.
Long Range
The long range forecast shows conditions remaining slightly below normal through the end of the work-week. There are hints that we’ll see warmer conditions build in by the weekend, but it’s too early to say for sure. In general, models show us transitioning to a generally warmer pattern toward the end of the month, although there will still be some cooler days mixed in here and there.
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:
Rainfall totals for the May 14, 2015
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
Friday
18°C / 7°C
Partly Cloudy
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.
SPC Day 3 Convective Outlook valid Saturday May 16, 2015
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.
Saturday
20°C / 9°C
Cloudy; scattered showers with the risk of a thunderstorm
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.
Sunday
10°C / -3°C
Rain
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.
The GDPS is a bit of an outlier, keeping rain wrapped tightly to the surface low pressure system in Minnesota and keeping the bulk of Sunday’s rain southeast of Winnipeg. ↩
More wet weather is on the way to Winnipeg & the Red River Valley as a slow-moving upper-level disturbance bears down on Southern Manitoba. The bulk of the rainfall associated with this next system will be quite a bit more concentrated than last week’s Colorado Low with much of the precipitation being produced by a single, relatively narrow band of moderate rainfall sliding across the region.
Winnipeg will see a high of around 12°C today with cloudy skies through the day. Shower activity will push northwards through the Red River Valley over the morning hours bringing a decent chance of some rain to Winnipeg by mid-to-late afternoon. Winds will be breezy out of the southeast at around 30km/h with a bit of gustiness on top.
Clouds will stick around tonight as the temperature drops to around 7°C with a continued slight chance of showers through much of the overnight period. The next disturbance will move into Southern Manitoba late overnight, spreading rain from SW to NE starting near the Pilot Mound/SW RRV region and lifting towards Winnipeg.
The NAM is forecasting around 10-15mm of rain for much of the Red River Valley on Thursday, with some areas seeing as much as 20-25mm.
Thursday will start off as a fairly rainy morning, then see rain taper off from west to east through the afternoon. Skies will remain cloudy through the day with winds out of the east. Expect a high near 13°C. The low on Thursday night will be around 7°C under mainly cloudy skies.
When all is said and done, it’s possible we’ll see somewhere from 10–20mm of fresh rain, however this entire system may end up shifting slightly further west which would leave the Red River Valley fairly dry until remnant showers pass through on Thursday night. We’ll be sure to keep tabs on things as they develop through the day and update with the most likely outcome later tonight.
Friday will bring a break from the gloomy weather as things clear out through the morning, leaving us with sunshine and a high near 19°C and light winds.
Long Range
This weekend will bring another disturbance through the region that has the potential to produce a significant amount of rainfall – 25–50mm – however there’s still a lot of uncertainty associated with the system and many divergent model solutions at the moment. It will likely be a generally unsettled week at best, and potentially a downright rainy one at worst. Some forecasts are showing some fairly favourable convective parameters on Saturday that would hint towards the first significant thunderstorm day of the year, but a decent capping inversion looks to keep things at bay as long as the current forecasts hold out.
We’ll see seasonal weather return this week after a chilly weekend. Temperatures will climb into the mid to upper teens by midweek.
Monday will remain cool as we stay in a northerly flow behind a departing low pressure system
Monday
Today will remain below-seasonal, but temperatures will warm somewhat over the weekend’s values. High temperatures should climb into the mid teens in the Winnipeg and Brandon areas. However, areas closer to the US border will remain under thicker cloud cover and will struggle to reach double-digits. The wind will be brisk at 30 km/h from the north.
Tuesday
Tuesday will be a nice day, as temperatures climb into the mid/upper teens under mainly sunny skies. Winds will be light as high pressure settles in over the region.
Wednesday
Wednesday will be similar to Tuesday, but there will likely be a bit more cloud cover as a system passes to our south. Temperatures will be in the upper teens under a mix of sun and cloud and light winds.
Long Range
It appears that temperatures will continue to warm through the end of the week. However, long range models hint at another weather system passing to our south next weekend, which may once again draw down some cooler air from the north. In general, models suggest that our weather will hover near normal values for the next couple weeks.
