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.