Sorry for the infrequent postings lately; external circumstances have made it difficult to keep up with things. Next week should return back to quasi-regular posting.
Again, my apologies.
This article on Rob’s Blog summarizes the generalities of the upcoming week well.
As we quickly approach the beginning of fall, Winnipeggers can be happy to know that after the next couple days, the mitts can go back into the closet.
So what’s on tap? For this evening, most of the RRV should see heavy drizzle or light rain as a trough line moves through that connects two low pressure systems: one in central Saskatchewan and one in South Dakota. The precipitation will move out overnight and tomorrow will bring mainly cloudy conditions with scattered drizzle and moderate northwest winds. Showers or drizzle may make an appearance downwind of the lakes, but nothing widespread is expected.
On Wednesday afternoon into the overnight period, areas close to the International border may see some showers spread north from a system moving through the Dakotas, however it seems to me that the models are underestimating the effect of the ridge that will be positioned across the central Prairies. It’s likely that the dry outflow from the ridge will keep things cloudy instead of rainy over southern areas of the RRV.
The rest of the week looks quite nice with sunny skies through much of the RRV and temperatures climbing into the high teens. There’s definitely a chance that Winnipeg will see temperatures over 20°C, however I’d currently bet on just high teens as the models tend to over-amplify upper ridges in 60+ hour forecasts. A string of disturbances will trek across the Dakotas, and there is a slight chance that some precipitation will nudge into areas near the international border, but for the most part, expect the second half of the week to be warm and dry.
As one other note, it looks that from here out, overnight lows look to be in the 5-10°C range, which is good news for farmers in the RRV, many of whom were able to escape the frost which affected Winnipeg and areas north and west on Saturday night. Drier, frost-free conditions are sure to be good news for many of the province’s farmers.
Afternoon showers in the RRV with the slight chance of an isolated thunderstorm or two will mark the arrival of a much cooler arctic airmass in Southern Manitoba.
Under cloudy skies most of the day, the RRV will see increasing southerly winds today as a low pressure system approaches from Southern Saskatchewan. As the low passes by this afternoon into the early evening, the RRV will see widespread showers with the slight chance of a thunderstorm.
Friday 21Z 3hr QPF w/MSLP Panel from GEM-REG 00Z Run
Current indications are that most of the RRV will see 5-10mm of rain. There may be accumulations up to 15mm in a few isolated localities due to enhanced convection. The rain will end by midnight with only a slight chance of a few hang-back showers in the cooler air.
The main story after that is that Winnipeg will be under a much cooler airmass.
Sat 00Z 850mb Temperature Panel from GEM-REG 00Z Run
With current 850mb temperatures hovering around 6°C, expect a chill in the air in the mornings over the weekend as the 850mb temperatures get down to the -2°C range. This should translate to overnight lows of -3 to 0 through much of southern Manitoba over the weekend.
Pick your tomatoes if you haven’t! This weekend certainly holds the potential for widespread frost with the cooler air moving in over the Province. The areas most likely to see frost would be areas west of the RRV, and locales in the RRV north of Winnipeg, with patchy frost possible to the south and southeast of Winnipeg.
Showers and isolated thunderstorms will push into the Red River Valley tonight, signalling the start of the next major low pressure system to move across the prairies.
A low moving NE out of Eastern Montana has spread rain into much of Southern Saskatchewan through the day today, and is posed to bring more rain into Southern Manitoba. Thunderstorms have initiated along a warm front draped W-E across North Dakota and will move northwards, supported by a 40-50kt southerly 850 jet and large scale ascent with a strong southerly flow aloft overriding the warm front.
Winnipeg should see rain beginning late this evening into the overnight period and through much of the day tomorrow as the precipitation will continue to blossom coming out of the United States. All in all, most of the Red River valley should see 20-30mm of rain by the time the rain lets up on Friday evening, with local amounts possibly reaching 50mm underneath a few of those isolated thunderstorms, should they manage to develop.
This is, unfortunately, not good news to many of the Farmers in the RRV, who have had to battle saturated grounds through much of the latter half of the summer. This is also bad news for the RRV in general, as we continue to have the soil re-saturated as we approach the winter freeze. Should a long stretch of dry weather not occur, this wet fall could lead right back into a wet spring due to overland flooding.
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