Friday, March 03, 2017

Milder weekend ahead.. winter storm system looms for Monday

After a cold start to March, things will be turning milder this weekend as a southerly flow flushes out the Arctic airmass currently over the eastern Prairies. In Winnipeg, temperatures are expected to climb to the freezing mark on Saturday and +2C on Sunday. Note however that Saturday will see gusty south winds gusting 60-70 km/h, so that high of 0C will feel a lot colder. Sunday looks a lot more pleasant with lighter winds and temperatures above freezing.

12Z NAM model valid Monday afternoon shows
rain over SE MB and snow west
Attention then turns to a potential winter storm system that will be impacting southern Manitoba Monday into Tuesday. At this time, models are indicating the development of a storm system over the western United States Sunday that will track across the Dakotas Monday and intensify as it moves into NW Ontario by Monday night. This system will likely start off with some rain or freezing rain over the RRV and SE Manitoba with snow over western MB and he Interlake regions. As the storm pushes towards the Ontario border later Monday, strong northwest winds on the backside of the system will draw in colder air and spread snow and blowing snow across the remainder of southern Manitoba Monday afternoon into Monday night. Travel conditions could become hazardous across southern MB through the day Monday into Monday night, especially with falling temperatures and increasing winds that will freeze up any standing water from leftover rain or melted snow.

12Z GDPS model valid Monday evening shows
intensifying storm over Lake of the Woods 
There's still a lot of uncertainty on the track of this system and the timing when precipitation will change over to snow which will impact overall snow totals.  A track across southeast MB would push the heaviest snow over western Manitoba through the Interlake regions (possibly 15-25 cm) with lesser amounts (5-10 cm) over the RRV and SE MB.  A track through Lake of the Woods or east would bring heavier snow over the southern Interlake and RRV. We'll continue to monitor trends over the next few days to get a better idea of how this storm will track, and what impacts it will have for southern MB. In the meantime, be prepared for a potential return of wintery conditions Monday into Tuesday. Stay tuned..