Long awaited spell of sunshine and drier weather..

After 10 days of generally cool, cloudy and unsettled weather.. the weather pattern will finally be shifting to a drier and warmer trend, at least for the next few days.  Unsettled weather will be moving into the Great lakes while an upper ridge of high pressure builds over the western Prairies by the end of the week. That will allow a much needed break from the frequent storm systems passing through the southern Prairies. After a chilly night tonight with patchy frost in areas, Wednesday should be the nicest day we've seen in a while with plenty of sunshine and temperatures approaching 20C, a mark we haven't hit in Winnipeg since the 23rd.  Even milder weather is forecast Thursday with sunny skies and highs in the low 20s. Friday may see some increasing cloud and a small chance of showers, but generally most places should be rainfree with drier and warmer conditions expected into the weekend.  More organized shower activity is possible later Sunday into Monday as a system tracks across the Prairies.

More rain on the way..

A large area of rain associated with showers and thunderstorms that fired up over the Dakotas overnight is spreading over southern Manitoba and the Red River valley this morning. The main area of rain should be spreading into Winnipeg by mid morning, with about 5-10 mm of rain through midday before tapering off to a few scattered showers this afternoon. Additional showers are possible later this afternoon into this evening with a chance of thunderstorms as the main storm system pushes towards the international border.  Showers should taper off overnight but are likely to move back in Monday afternoon and night as an upper low tracks across southern MB.  Temperatures will continue to run some 10C below normal today and Monday. All in all, a rather dreary forecast for the next few days before we see a turnaround later in the week.

Late season snow blankets parts of western MB

Photo submitted to The Weather
Network shows enough snow to
build a snowman in Russell, MB
May 25 2012

An unseasonably cool airmass combined with moisture from a trough of low pressure over western Manitoba brought a late season snowfall to parts of western Manitoba and eastern SK last night. A cold rain started last evening then changed to wet snow overnight with a few cm of slushy accumulation over the Riding and Duck Mtns and areas near the SK border.  Dauphin and Swan River had a coating of wet snow while 4 cm was recorded in Rossburn, and 4-7 cm through Russell and Roblin MB.  Kamsack, Yorkton, Melville and Regina SK also recorded some wet snow last night.  Snow this late in the year is unusual, but not unprecedented over southern MB, especially in the higher elevations of western MB. Just 3 years ago on May 15th 2009,  the Dauphin area was hit with 20-30 cm of snow from a late season storm. On May 31- June 1 1985, Dauphin and area recorded about 5 cm of snowfall (same day as the Barrie tornado outbreak in southern Ontario). On June 5-6 1901, 5-10 cm of snow was reported in the Turtle Mountain area and parts of western MB.  In Winnipeg, the latest measurable snow on record was 0.5 cm on June 8 1877, with a high of only +5.6C that day.

Major cooldown for Friday and Saturday.. Snow possible for western MB Thursday night? Frost possible Saturday morning over RRV.

Enjoy the 20C temperatures today.. because it will likely be a while before we see temperatures that high again over most of southern MB.  A low pressure system crossing southern Manitoba on Thursday will drag a cold front across the regions later Thursday into Thursday evening, ushering in a much cooler airmass from the north. Showers behind the front Thursday evening may even mix with or change to.. (yikes!) snow.. over higher elevations of western MB Thursday night into early Friday.  Friday will be an unseasonably cool day across southern MB with mainly cloudy skies and temperatures only around 10C for daytime highs..  over 10C below normal for late May.  Skies are expected to partially clear Friday night, which will bring the potential for frost across much of southern MB including Winnipeg by early Saturday morning. Gardeners beware.  Saturday should be dry for the most part, but another major system moving out of the American south will push a warm front into the Dakotas, triggering another round of showers and thunderstorms Saturday night into Sunday over southern MB, with the potential for locally heavy rainfall yet again. Generally dry but cool weather is expected into the first part of next week before a warming trend later in the week.   

Another round of showers and thunderstorms tonight.. locally heavy rain and hail possible

Another round of showers and thunderstorms is on tap for southern Manitoba tonight as a low pressure system over the Dakotas pushes a warm front towards the Manitoba border. Warm and increasingly humid air will spread up through the Dakotas today while cooler air remains entrenched over the southern Prairies. The clash of airmasses and favourable dynamics aloft  will result in widespread showers and embedded thunderstorms developing later today into this evening across southern Manitoba. The best chance of heaviest thunderstorms will be over the Red River valley and southeast MB where strong to locally severe thunderstorms from the Dakotas will be tracking across the border by this evening, as well as developing along the warm front. Main threat with these storms will be large hail and strong winds, with areas of very heavy rain (25-50 mm) possible.  A secondary area of heavy rain is also likely through the Interlake regions tonight into Wednesday as an upper low over southern Saskatchewan tracks slowly eastward into the Manitoba lakes region. Conditions are expected to dry out Thursday and Friday for most of southern Manitoba (rain still possible near Ontario border Thursday)  before more unsettled weather moves in for the weekend.  All in all, a generally unsettled week ahead as we get into a more stormy and variable pattern.   

Thunderstorms bring heavy rain, hail to Winnipeg and southeast MB..

Rainfall accumulation estimates from
Woodlands radar showing track of storms
Friday evening. Note swath of yellow and
orange returns through Winnipeg and
northeast, and another line from
  Steinbach to Lac Du Bonnet. 

It was a stormy start to the May long weekend as a line of thunderstorms developed rapidly just west of Winnipeg Friday evening, tracking over the city between 8 and 9:30 pm bringing heavy rain and hail through much of the city.  The storms fired up just southwest of Winnipeg by about 7:45 pm and within 15 minutes were bringing torrential rain to southwest parts of the city. The cells continued to track over downtown bringing heavy downpours and lots of small hail, enough to accumulate on the ground in areas like River Heights and Wolseley. The storms produced a swath of about 25-35 mm of heavy rain from the southwest part of the city through the downtown core into the northeast (see radar image left), with much less rain on the southeast and northwest perimeters of the city. At my station in Charleswood, I recorded 27 mm of rain between 8 and 9 pm with a peak rainfall rate of 133 mm/hr at 8:11 pm. Even higher amounts of 30-35 mm of rain were recorded downtown (U of W) and the northeast parts of the city (E St Paul)   The storms were part of a complex frontal system passing through southern MB Friday evening that was ushering in cooler air for the start of the May long weekend. Unsettled weather with periods of rain and cool northwest winds will start off the holiday weekend Saturday with another 10-20 mm of rain possible, before drier more pleasant weather moves in by Sunday into Monday.

Showers/thunderstorms possible Friday into Friday night.. improving weather for holiday weekend..

High pressure over southern Manitoba today will give way to an increasing southeast flow ahead of a large scale storm system that will be developing over the western US plains/Rockies over the next couple of days.  This system will draw increasingly more humid air from the southern US Plains by the end of the week, along with warmer air. This will lead to an increased chance of showers and thunderstorms over southern MB Friday, first ahead of the warm front in advance of the system, then along the cold front later Friday into Friday night.  There is the potential for locally strong thunderstorms by Friday night, however that will depend largely on how much humidity can be drawn up with this system, and how much cloud will be around with the warm front.  Cloudy and unsettled weather Saturday is expected to clear out by Sunday along with cooler temperatures, before a generally pleasant end to the holiday weekend with sunny skies and near normal temperatures Monday.

Warm windy weekend sparks wildfires over southeast MB..

The windy warm and very dry weather this weekend has helped to fuel at least two wildfires over southeast MB, including a fire near Woodridge (NW of Sprague) that has grown to over 1300 hectares. The weather has been ideal over southern MB this weekend with sunny skies and warm temperatures in the mid 20s. However, the beautiful weather has also been accompanied by brisk westerly winds gusting to 50 and 60 km/h at times, along with very low humidity levels of 15-20% in the afternoon.  Those are prime conditions to promote fire growth, particularly in areas that are quite dry, such as the Red River valley and SE Manitoba. More of the same weather is expected Monday although winds won't be as strong, with gusts to 40 or 45 km/h by the afternoon. RH values will still be low in the 20-25% range. A cold front is expected to cross southern MB Monday night bringing slightly cooler and less windy conditions for Tuesday and Wednesday, although little precipitation is expected with dry conditions persisting much of the upcoming week.

Nice weekend ahead.. warming trend into early next week

A dry westerly flow across the Prairies will maintain sunny skies and pleasant weather across southern MB this weekend, with temperatures rebounding back into the 20s. Mother's Day on Sunday looks especially nice with afternoon temperatures climbing up to the mid 20s after some morning cloudiness. The warm dry weather is expected to continue through the first few days of the new week, before a cold front ushers in a few showers and cooler weather by Thursday.

Warmer weather on the way.. first 25C day likely Thursday

Cloudy and cool conditions over the past couple of days will give way to sunnier skies and warmer temperatures Wednesday and Thursday with temperatures climbing into the 20s. In fact, it looks like Winnipeg will see its first 25C reading of the year by Thursday as a southerly flow pumps in a warmer airmass over southern MB. A cold front will bring some showers and possible thunderstorms to southern MB Thursday night, with clearing and cooler conditions expected Friday. This should give way to a dry and pleasant weekend with temperatures rebounding back towards the 20C mark. Dry and warm conditions are expected through the first half of next week with temperatures in the 20s as an upper ridge of high pressure builds over the central continent.

Generally cool and unsettled weather through Monday..

The weather picture will be dominated by generally unsettled conditions over the next few days over southern Manitoba as a series of weather disturbances pass though the region. The first wave of unsettled weather is pushing into SW Manitoba this morning with a large area of showers which will continue to progress eastward into the Red River valley by tonight, although precipitation is expected to become lighter by the time it reaches the RRV. General rainfall amounts of 10-20 mm are forecast today over SW Manitoba with just a few mm over the RRV tonight. Shower activity will move out Saturday with a generally dry day expected before the next area of showers and possible thunderstorms pushes in for Sunday. This may bring higher amounts of rainfall over the RRV and southern MB with 10-25 mm possible depending on how much thunderstorm activity develops. Currently models are suggesting that the bulk of rainfall over the next 3 or 4 days will occur west and south of the RRV over southern SK, southwest MB and the Dakotas. Scattered showers and cool weather are expected Monday over southern MB before a drying and warming trend by the middle of next week.