Friday, April 29, 2011

Strong storm system to bring significant rain, snow and wind to southern MB this weekend

Don't let that 22C sunshine today fool you.. Old Man winter is still lurking in the Prairies and will make his presence felt within 24 hours as an intensifying storm system moves across North Dakota tonight into Saturday. In advance of this system , rainshowers will overspread southwestern MB tonight and become more widespread overnight as they push into the Red River valley. Rain will continue Saturday in southeastern MB while colder air moving into western MB will change the rain to snow Saturday morning. Snow will increase in intensity as strong northerly winds to 70 km/h brings in unseasonably cold air, producing poor visibilities in snow and blowing snow. Travel will become difficult over southwestern MB into the Interlake regions Saturday into Saturday night where winter storm warnings are in effect for 10 to 20 cm of snow, with even greater amounts possible over the higher elevations of Riding and Turtle Mountains. The heavy snow and strong winds may also lead to local power outages. Rain will change to snow from the west during Saturday, reaching Portage by afternoon and Winnipeg by evening. At this point, it looks like Winnipeg and the RRV will see about 5 cm of snow Saturday night accompanied by cold northerly winds with temperatures dropping below freezing making for poor travel conditions. If the storm moves slower, Winnipeg could see greater snowfall amounts. The storm is expected to move into NW Ontario Sunday leaving cloudy skies and cold temperatures in its wake.

While unusual, snowfall at this time of year is not unprecedented. In 1967, Winnipeg saw 21 cm of snow on May 1st. In 2004, a snowstorm on May 11-12th produced 20-30 cm of snow across southern MB including Winnipeg leading to the shutdown of the TransCanada highway. Here is a list of Winnipeg's heaviest all time May snowfalls..

1. May 11, 2004.....31 cm (estimated)
2. May 1, 1967.... 21.1 cm
May 19, 1931.....20.3 cm
May 9, 2002.....20.0 cm
5. May 20, 1882.....15.2 cm
May 5, 1938.....13.0 cm
May 5, 1931.....12.2 cm

Thursday, April 28, 2011

Intensifying storm system to bring showers Friday night.. colder weekend with possible .. snow??!!

An intensifying storm system is forecast to track across southern Manitoba Friday into Saturday, bringing some widespread precipitation across the Dakotas and southern Manitoba. The system is expected to push a band of showers across the Red River valley late Friday into Friday night, with isolated thunderstorms possible over the far south into the Dakotas. General rainfall amounts of 10 - 20 mm are possible across southern MB by Saturday morning, with locally higher amounts in thunderstorms. On Saturday, the storm system is forecast to track east of Lake Winnipeg, dragging colder air on the backside of the system, and changing rain to wet snow mainly over the Interlake regions although some snow could also fall in Winnipeg Saturday into Saturday night. Cold weather will persist through Sunday with temperatures well below normal for the beginning of May.

Sunday, April 24, 2011

Some nice temps for Easter weekend..

Looks like we'll finally be seeing some nice springlike temperatures today, with sunshine and a westerly breeze allowing temperatures to climb to 17C today in Winnipeg. The atmosphere should be a little more stable as well so we shouldn't see much in the way of convective afternoon showers developing like the past few days. All in all, a nice Easter Sunday on tap. On Monday, a "back door" cold front is forecast to slip into the Interlake region as a cooler high pressure system moves across Northern Manitoba. This will bring cooler temperatures to the interlake regions Monday, while mild weather prevails over the far south with temperatures climbing to 20C for the first time this season, especially over the southern RRV. There is some difference in opinion on where this back door cold front will lie Monday as some models suggest the front will push south of Winnipeg, bringing northeast winds and slightly cooler temperatures for us (around 15C) Other guidance suggests the front will lie just to our north, allowing temperatures to rise to the 20C mark in Winnipeg. We'll have to see who's right, but the 21C forecast for Winnipeg Monday will be in jeopardy if that front settles a bit further south.

Tuesday looks mild again with temperatures in the upper teens with generally dry weather and near normal temperatures (around 15C) expected for the upcoming week. Long range guidance is hinting of a possible storm system over southern Manitoba by next weekend.

Tuesday, April 19, 2011

Precipitation possible Friday and next Tuesday as Red River crest heads north..

A weak system will cross the Dakotas on Friday bringing a band of light rain to the Red River valley. Precipitation amounts are expected to be light with 2-5 mm over most areas of southern MB, and perhaps 5-15 mm over the North Dakota portion of the Red River valley. Precipitation may even be mixed with some wet snow early Friday morning. Things are expected to dry out for the weekend before another stronger system develops by Tuesday over the central Plains briging another round of precipitation and storms mainly south of the border. Some precipitation however is possible over southern MB Tuesday into Wednesday, although the bulk of precipitation is again expected south ot the border. Precipitation amounts should not have a dramatic effect on the levels of the Red River and its expected crests next week into early May. However, the extra precipitation may prolong the length that river levels stay high.

Temperatures will remain cooler than normal through the end of April and likely into the beginning of May as the overall pattern continues to favour a strong storm track south of the border with cooler air over much of the Prairies.

Wednesday, April 13, 2011

Snow possible by weekend over southern MB

A strong storm system moving into the Central US plains this week is poised to bring a large area of rain and wet snow to the Northern Plains, with some snow likely working its way into southern Manitoba Friday into Saturday. The bulk of precipitation is expected to fall over the southern Dakotas into the northern Mississippi Valley where totals of 50 mm or more are possible, but a band of rain and wet snow is forecast to spread northward into southern Manitoba during Friday, likely changing to snow Friday night into Saturday even across the Red River valley. Much of the snow should melt initially, however some accumulations are possible especially over higher terrain. Like it or not, winter ain't done with us yet.

Tuesday, April 05, 2011

Flood links

As the Red River rises, here are a few links that will come in handy over the next few days and weeks ahead..

Winnipeg city river levels (real time)

NWS Grand Forks Hydrology link

Manitoba Water Stewardship link

Manitoba Flood cams (8 across southern MB)

Winnipeg Red River flood graph (James St levels)

Free Press Flood coverage

CBC flood coverage

CTV flood coverage (includes 2 floodcams)

Saturday, April 02, 2011

No joke.. spring storm system to bring snow across southern MB overnight into Sunday

A beautiful springlike start to the weekend will end on a wintery note as a spring storm system tracks across the Dakotas tonight into Sunday bringing an area of snow to southern MB. Snow will spread into southwest MB this evening, possibly mixed at first with some rain before becoming heavy at times tonight. A snowfall warning is in effect from Melita to Pilot Mound where 10-20 cm is possible by Sunday, especially over higher elevations. Further east.. precipitation will likely begin as rain overnight in the Red River valley including Winnipeg, before changing to snow early Sunday. Wet snow, possibly heavy at times will continue Sunday before easing later in the day. Snow will likely melt initially however, 5-10 cm of heavy wet snow is possible in Winnipeg and the RRV by the time the snow taper offs by Sunday evening. Travellers should be prepared for a return to wintery weather Sunday over the RRV and much of southern MB with slippery road conditions and poor visibilities at times in heavy snow.