Unfortunately, I don’t have time today to do a full write-up on what’s going on. This link is to a comment I made on another weather website. It’s rather technical, so I don’t feel it’s a good fit for my blog, but if you’re interested in seeing something a little more complicated than what I tend to post, check it out! 🙂
Tag: Thunderstorm
Afternoon Showers & Cool Weather (and Frost!)
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 With A Chance of Thunderstorms Tonight & Friday
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.
Unsettled Weather in Store Next Week
Having broken the 30° barrier another time in the 2010 summer, summertime sun will give way to more unsettled weather next week.
A weak cold front will pass across Southern Manitoba tonight, bringing with it a very slight chance of showers (most likely nothing) and moving us into a cooler airmass for tomorrow, which should be a mostly cloud day.
By Monday morning, a warm front (shown above in the 850mb temperatures) will be positioned SW-NE across Southern Manitoba, extending from a surface low positioned in central North Dakota. For several days, as the low moves northeast along the baroclinic zone, scattered showers will ride along the warm front. Each night, there exists a potential for non-severe nocturnal thunderstorms in the RRV and east near the intersection of the warm front and a weak 850mb jet extending up into Southern Manitoba. Most of the energy associated with the 850mb jet will remain in the states, so I don’t think that any severe weather will be on tap.
Get out and enjoy tomorrow, Sunday through Wednesday will be cooler (think low 20’s for highs) and rather unsettled, with mainly cloudy skies with occasional sunny breaks and showers lurking around during the days, with areas of organized precipitation occurring overnight. on Sunday night and Monday night.
