Another low pressure system tracking through the Canadian Prairies has brought sunshine and hot weather for Monday, but will one of the thirstiest areas on the Prairies see any rain out of it? Read on to find out…
Multispectral Satellite Image of the Canadian Prairies valid at 3:45PM in Winnipeg.
A strong low tracking across the northern Prairies has brought temperatures into the low 30’s to Southern Manitoba, with higher humidity creating humidex values of 35°C – 37°C over south-central and southwest portions of the province. This warm, humid air has been brought in by a southerly wind ahead of a secondary disturbance tracking across the southern Prairies.
Things will change overnight as the entire system moves into our area and exits the province quickly tomorrow. Thunderstorms should develop ahead of a shortwave disturbance tracking through Southern Saskatchewan this afternoon, then develop into an area of rain with embedded thunderstorms as it moves into southwest Manitoba this evening as the low level jet (LLJ) begins to intensify. The track of these two distinct features, the shortwave and the LLJ, will be crucial for Winnipeg’s chances of seeing any rain overnight or tomorrow.
Currently, the shortwave is expected to track near Winnipeg, but likely somewhere north of the city, while the LLJ should track eastwards through the Southern Red River Valley. Should the LLJ pull off into North Dakota, the shortwave track further north into the Interlake, or some combination of the two, Winnipeg will likely see what we’ve seen for over a month now: a solid wall of rain that splits and goes around either side of the city without giving us a drop.
What do current indications show? Well, so far the actual shortwave seems to be captured very well by most models, which is a good thing. The GEM-REG model is very precipitation happy, bringing 10-20mm of rain through Winnipeg tomorrow, starting around 6-7 in the morning.
12Z GEMREG Model, 12hr. QPF valid 00Z Wed the 17th (Tuesday Evening in Winnipeg)
There are naysayers in the model world though. Both the NAM and the GFS models hint at the splitting rain pattern:
12Z GFS Model, 12hr. QPF valid 00Z Wed the 17th (Tuesday Evening in Winnipeg)
12Z NAM Model, 12hr. QPF valid 00Z Wed the 17th (Tuesday Evening in Winnipeg)
Both models show significantly less precipitation than the GEM through the Winnipeg area, with heavier amounts to the North/Northwest and across the Int’l border in ND. Ensembles paint fairly large amounts of precipitation over Winnipeg for tomorrow as well.
My gut feeling? I think that this system will lift north quicker than many of the models are seeing, and a gap in the precipitation will develop as the LLJ separates from the shortwave. However, I do think that the LLJ will be able to sustain enough precip to give us a batch of rain in the morning, but probably only 3-5mm. Of course, if any thunderstorms survive to Winnipeg, that amount could be significantly higher. I certainly don’t think it’s going to rain all day, but tomorrow still looks like our best shot for some significant precipitation that we’ve had in a long while.
Expect things to clear up by mid-afternoon as some drier air pushes in with the gusty westerlies that will move in. The rest of the week looks nice with plenty of sunshine and highs in the mid-20’s. There might be a slight chance of showers overnight on Thursday into Friday, but we’ll take our battles one at a time.
What do you think? Will Winnipeg finally see an end to this dry spell?