Today in weather history

50 years ago today in 1958, an unseasonably strong late season blizzard struck southern MB including Winnipeg, bringing 5 to 10 cm of snow, powerful wind gusts to 100 km/h or more, and record low temperatures. Winnipeg set a record low temperature of -13.3C that day, less than 24 hours after reaching a mild 15C the day before.

In Winnipeg, the cold front pushed through by 2 am that morning, sending temperatures of +4 to below freezing. By 6 am, the temperature was down to -8C and snow started to fall with winds increasing from the northwest. By 10 am, visibilities were down to 400 metres in snow and blowing snow, and temperatures had dropped even further to a record cold -13C. From noon to 4 pm, NW winds of 60 gusting over 80 km/h were giving blizzard conditions with visibilities down to 200 m at best. Temperatures were exceptionally cold, rising to only -11c by 4 pm (some 25 degrees colder than the day before) with windchills of -25 or lower. By 6 pm the blizzard was lifting, with skies clearing by 8 pm.

What a day that must have been! After hitting 15C on the 27th, much of southern MB would be hit with a severe blizzard the following day with almost January like weather. Wind gusts up to 87 km/h were reported in Winnipeg that day, with 100-105 km/h gusts around Portage La Prairie. The afternoon high of -8.3C in Winnipeg is the coldest ever for so late in the year, and is unequaled for its late season severity. I wonder what the forecast was calling for back then, and how did residents cope with such a drastic change in the weather?

Clearing skies reveal storm snow tracks

Satellite images today clearly reveal the snow tracks left from two late season winter storms that have affected southern MB over the past couple of days. The first track of snow extends from the Pilot Mound area through Portage to Gimli left over from Thursday's storm (April 24th). 10-20 cm of snow fell in this swath, with Winnipeg lying just on the eastern edge of the heavier snowband. Winnipeg saw a mix of snow and ice with this system with mainly rain or freezing rain further east. The second track of snow is over southeast MB just east of Winnipeg. This is snow left over from Saturday's storm (April 26) which dumped 15-25 cm across southeast MB closer to the Ontario border. This same storm system dropped record breaking snowfalls of 30-50 cm from northeastern SD into northern MN and NW Ontario. Quite the stormy finish to April!

Second storm system to affect NW Ontario tonight

Another storm system from the central Plains states will be moving north today, bringing an area of heavy snow to areas just east of the MB/Ontario border tonight into Saturday morning. Snow is expected to spread into northern Minnesota late today and across the border into NW Ontario this evening. Snow amounts will be heaviest between Kenora and Atikokan, where 15 to 25 cm of snow is possible by Saturday morning. The MB/Ontario border is expected to be on the western edge of the heaviest snow area.. with 5 to 10 cm possible in places like Sprague and Falcon Lake. Travellers heading east into NW Ontario or northern MN tonight into Saturday morning should be prepared for more wintery weather and poor driving conditions.

Messy mix for the Thursday morning commute

A winter storm watch has been issued for much of southern MB as a low pressure system from the Dakotas spreads an area of precipitation up from the south beginning tonight. The precipitation will start off as band of rain (with possible thunderstorms) near the international border this evening spreading north through the evening. As it moves north, it will encounter colder air aloft and rain will change to snow over southwest MB and the northern Red River valley by midnight continuing overnight into Thursday morning. Precipitation will likely stay mostly as rain over southeast MB tonight before changing to wet snow early Thursday. In between the rain and snow areas, there may be a band of freezing rain and ice pellets cutting though the Red River valley including Winnipeg overnight.

Snow accumulations with this system will be highly dependent on elevation and the position of the rain/snow line.. but at this point, it appears areas north and west of Winnipeg will see around 10 cm of snow overnight with up to 20 cm possible over higher elevations west of the Red River valley. Areas south and east of Winnipeg will see more rain at first before the changeover to snow, so snow amounts in these areas will only be in the coating to 5 cm range. Here in Winnipeg, snow amounts will be a tough call since we'll be right on the rain/snow line much of tonight, but as a first guess, 5 to 10 cm are possible by midday Thursday, although some of that will melt initially due to the warm ground. Note that this system has the potential for heavy precipitation rates due to elevated convection, thus snow or freezing rain could be heavy at times overnight into Thursday morning. In areas that are cold enough for snow, this will mean very poor visibilities in heavy snow, with snowfall rates of 2 to 3 cm/hr possible at times. All in all, a messy commute to work and school Thursday.. be prepared for anything!

Double trouble to end work week..

Two weather systems are poised to bring a double shot of precipitation to southern MB and NW Ontario Thursday and Friday. Both systems will form over the central Rockies and move through the Dakotas into NW Ontario. The first system is expected to bring precipitation into southern MB Wednesday night tapering off Thursday afternoon. This system looks like it will bring rain over southeast MB changing to wet snow over southwest MB. Winnipeg and the Red River valley is expected to be on the warm side of this system at first but may change to wet snow before the precipitation tapers off. Heavier embedded showers and possible thunderstorms may bring soaking rains of 25 mm or more over portions of southern MB with 10 cm or more of wet snow possible over higher elevations of western MB. The second system on Friday, tracking a little further east, will encounter colder air on the backside of Thursday's storm and may bring accumulating snow to southeast MB and NW Ontario including the Whiteshell and Lake of the Woods. An unsettled end to the work week.. with significant amounts of rain and/or wet snow to parts of southern MB and NW Ontario. Stay tuned..