The Upcoming Week

Sunshine and warm temperatures are the name of the game this week.

There’s not much to say for this week other than enjoy the nice weather.  A broad upper ridge will dominate the weather over the southern Prairies through most of the week.

12Z GEM-REG 500mb Heights & Speed valid 12Z Wednesday Oct 6.

A broad upper ridge sitting over the southern Prairies is bringing temperatures into the low to mid 20’s over Southern Saskatchewan and temperatures near 20 for Southern Manitoba.  This upper ridge will give way to a weak upper trough that will move across the Prairies Tuesday and Wednesday, however any rain associated with it will stay well north of the RRV and not effect our temperatures too much with them being limited only to the high teens.  After the trough moves by, then the upper ridge begins to build back and temperatures should head back into the low 20’s for the week’s end.

A warm and dry outlook is sure to be welcome news for farmers who have been battling waterlogged fields through much of the summer.

Mostly Sunny

Models indicate that there is a chance of showers late overnight and into tomorrow morning, and then we should return back to mostly sunny skies before cooler air pushes in for the weekend.

The GEM-REG model is currently the most aggressive in pushing rain through southern Manitoba tomorrow morning, as shown above in the 12H precipitation accumulation map valid 12Z Wednesday morning.

Sunny skies this evening should cloud up overnight as a cold front passes through southern Manitoba.  Most models lean towards just a slight chance of showers for the RRV, with a majority of the precipitation occurring in Northwestern Ontario.  The GEM-REG model, however, fires up a fair line of showers along the front as it passes through overnight, giving up to 5mm of rain to the RRV.  This solution currently looks to be an outlier, however so far this cold front has had a good history of precipitation along it.

Either way, it’s fairly certain that any accumulations that do develop should stick to the 5mm range, and will certainly be less than 10mm.   After the front passes through, we should see another mostly sunny day with a few clouds scattered around.

By Friday, as an upper ridge builds in the western Prairies, we should see a brisk northerly flow develop as a cold front slumps down through the province.  Expect cloudier skies than the forecast currently suggests in the afternoon.  The good news is that despite the chill in the air, precipitation is looking like it should stay north of Winnipeg.  Saturday looks to be a chilly day with 850 temperatures struggling to get above 0 for most of the RRV, and then we begin to transition back to warmer weather for the beginning of next week as the upper ridge moves east.

A Couple Unsettled Days, Then Warmer Weather Returns

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.