Wednesday and Thursday will be the warmest days of this most recent stretch of above average weather Southern Manitoba has been enjoying. The general trend of daytime highs being 5 to 10 degrees warmer than usual has been happening for some time now, and will be punctuated by today and tomorrow when temperatures may end up 15 degrees above normal for this time of year.
Averages for the first week of December are -7 daytime and -16 overnight.
"A combination of upper level ridging, and a warm airmass moving in from the southwest, coupled with strong southerly surface winds, will all add up to warm conditions for this time of year on Wednesday and Thursday," explained CMOS Accredited Weathercaster Chris Sumner. "Initially, it appeared we could be headed for potentially record breaking days, but that has since moderated, with highs now expected to land, both days, in the 5 to 7 degree range."
Sumner noted the amount of cloud cover the region sees during daylight hours will play a role in how warm things get.
"If cloud cover stays limited, and we see the maximum amount of sunshine we could get daytime, warmer conditions could be in the mix, and depending where you call home, pushing 10 degrees may be needed to set new daytime records."
According to Environment Canada, the following are the current daytime records for:
December 6th
Brandon (airport) - 14.4 (1939)
Winnipeg (airport) - 11.7 (1939)
Melita - 10.3 (2015)
Gretna - 9.9 (2015)
Pilot Mound/Carman - 9.0 (2015)
December 7th
Gretna - 10.6 (2015)
Melita - 9.1 (2015)
Pilot Mound - 9.0 (2015)
Carman - 8.6 (2015)
Brandon (airport) - 6.3 (1999)
Winnipeg (airport) - 5.0 (1939)
Looking ahead to later this week, a low pressure system coming off the Rockies, and expected to track eastward along the International border, could bring our next round of precipitation Thursday night and throughout Friday.
"There still is some uncertainty regarding how this low will move, and that will play a big role whether we see mostly rain, mostly snow or some sort of sloppy combination," Sumner said. "At this point, we’re not expecting significant accumulations, a few centimeters of snow, perhaps a millimeter or two of rain, but the fact we’re even talking about rain in December is quite unusual."
Following the departure of that system, a cold front sweeps through the region, ushering in much cooler air than the region has seen, pushing temperature back down to seasonal for the start of next week, alongside mainly sunny conditions.