Sunday, May 30, 2010

Thunderstorms swamp Winnipeg, southern Manitoba for second day..

Strong to severe thunderstorms pummelled southern Manitoba once again Saturday, dumping very heavy rainfall across much of southern Manitoba along with hail and wind gusts over 100 km/h. The Red River valley was particularly hard hit with 50-150 mm of rainfall recorded (see image from Grand Forks NEXRAD showing radar rainfall estimate over southern Red River valley). Winnipeg was swamped with 50-100 mm of rain Saturday causing numerous problems with flooded basements and underpasses, and rapidly rising river levels. (see time lapse video of storm as it moved through downtown Winnipeg late Saturday afternoon) Northeastern parts of the city including East Kildonan and Transcona were particularly hard hit with city gauges reporting up to 108 mm of rain Saturday through Saturday night. The rain comes on top of the heavy rain that fell across the northern Red River valley Friday when 50-80 mm was recorded in some areas. Below are some rainfall totals for the past 24 and 48 hours recorded up to 6 am this morning.

Location            total rainfall     total rainfall
Last 24 hours last 48 hours

Winnipeg, the forks 73.6 mm 95.0 mm
Winnipeg, airport 57.5 mm 82.6 mm
Emerson 102.2 mm 110.4 mm
Portage la Prairie 89.8 mm 91.4 mm
Pinawa 80.6 mm 87.8 mm
Brandon 63.0 mm 63.0 mm
Carberry 46.2 mm 46.4 mm
Carman 23.4 mm 49.4 mm
Gimli 18.0 mm 26.0 mm
Sprague 13.2 mm 48.4 mm

Other reports from past 24 hours..

Pembina ND........... 170 mm (6.73")
Emerson..................165 mm (unofficial but reliable)
Winnipeg Charleswood.. 71 mm (108 mm past 48 hours)
Oakbank............... 91 mm
Selkirk............... 78 mm
Beausejour............ 75 mm

8 AM MAY 29 - 8 AM MAY 30

Rainfall graph from Rob's Obs, Charleswood showing precipitation past 24 hours. The rain came in two waves, with 24 mm between 8 and 10 am, then another 42 mm between 6 and 11 pm. This comes on top of the 37 mm recorded Friday morning between 5 and 10 am.

Saturday, May 29, 2010

Severe thunderstorms, heavy rain hitting southern MB again..

Unsettled weather continues over southern MB today with more locally heavy rain, and severe thunderstorms. Heavy rain has set up just west and northwest of Winnipeg with local rainfall amounts of 40-65 mm reported. This band will be coming through Winnipeg this evening with more heavy rain likely.. which will compound local flooding concerns due to the heavy rains over the past day or so. Further south and east, severe thunderstorms with large hail and damaging winds are possible over the southern Red River valley and southeast Manitoba this evening.

Friday, May 28, 2010

Morning thunderstorms swamp northern Red River valley with heavy rain..

A line of thunderstorms ahead of a warm front produced heavy rain across the northern Red River valley Friday morning. The storms rolled into Winnipeg about 5 am and continued through much of the morning, dumping 25 to 40 mm of rain across the city by 10 am. A lightning strike even knocked off part of a church tower downtown around 6:45 am. The line of thunderstorms settled just south of the city between 8 and 10 am, dumping heavy rains of 50 to 80 mm from Elm Creek through Starbuck and La Salle to Landmark. (see map below) The showers and thunderstorms this morning are a prelude to what is expected to be a wet weekend over the Red River valley with additional showers and thunderstorms through Saturday into Sunday that threatens more heavy rain. This will elevate local flooding concerns if the heaviest rainfall occurs in areas already hit hard by heavy rain today.

Map showing rainfall amounts (in mm) from Weatherbug network as of 10:30 am

Highest rainfall totals Friday morning from Weatherbug and Manitoba Agriculture networks..

Glenlea.......... 78 mm
Landmark......71 mm
Elm Creek.......63 mm
La Salle...........62 mm
Sanford.........61 mm
St Adolphe........56 mm
Starbuck.........55 mm

Thursday, May 27, 2010

Wet weekend on the way..

It looks like May will be ending on a wet note as a slow moving low pressure system tracks across the Dakotas and southern Manitoba this weekend. This system will tap very warm and humid air over the central Plains producing several waves of showers and thunderstorms that have already spread into southwest Manitoba today. Additional showers and thunderstorms are likely tonight which will track across southern Manitoba overnight into Friday as a warm front settles along the international border. This front will mark the leading edge of very warm and moist air over the Dakotas with cooler air over the central Prairies. There will be a sharp temperature gradient across this front Friday with temperatures of 30C or more along and south of the US border, and only in the teens through the Manitoba Interlake. On Saturday the low pressure system and associated frontal trough will slowly move across southern Manitoba generating more showers and thunderstorms Saturday through Sunday. Rainfall could be heavy at times with local amounts of 50 to 75 mm possible across portions of southern and central Manitoba by Sunday evening. Cooler and unsettled weather will follow in the wake of the system early next week.

Tuesday, May 25, 2010

Strong winds today..

Strong south to southwest winds are expected across the Red River valley today as a deep low pressure system over eastern Saskatchewan tracks northward. An area of dry and unstable air over southern MB will tap very strong winds aloft (south 40-60 knots) to mix down to the surface, with sustained winds of 50-60 km/h, and gusts of 70-90 km/h at times. The strongest winds are expected through midday and afternoon before winds ease later today. Click here for live wind readings (in knots) from Winnipeg airport.

Monday, May 24, 2010

Another round of showers/thunderstorms on the way

Another low pressure system moving into the Dakotas today will spread more showers and possible thunderstorms into southern Manitoba today into tonight. The first batch of showers will spread into southern MB this morning from North Dakota with a few mm of rain possible as the band weakens. Later today into this evening, another round of heavier showers and thunderstorms is forecast to develop over North Dakota ahead of a warm front pulling warmer and humid air south of the border. This activity is expected to push into southern MB tonight with locally heavy rain possible. General rainfall amounts of 10-20 mm are likely with this second wave, however local amounts of 20-40 mm are possible in areas that see thunderstorms.

Friday, May 21, 2010

Holiday weekend outlook update..

Unsettled weather will be moving into southern MB for the holiday weekend.. especially Saturday into Saturday night when showers and thunderstorms with locally heavy rain are possible. The heaviest activity is expected west of the Red River valley overnight into Saturday where 25 to 40 mm of rain is possible with locally heavy thunderstorms. This activity will push east into the RRV by Saturday night. Drier weather is expected Sunday into Monday, before more showers move in Monday night into Tuesday.

The weekend outlook for Winnipeg and the RRV..

Saturday..Partly to mostly cloudy and breezy with a chance of showers or thunderstorms. Showers and thunderstorms over western MB spreading east into the valley by evening. High 24.
Saturday night..Showers and thunderstorms. Rainfall amounts 10-20 mm possible.
Sunday..A mix of sun and cloud. High 23.
Monday..Sunny at first then clouding over with showers developing Monday night. High 20.

Wednesday, May 19, 2010

Unsettled weather moving in for holiday weekend

After a summerlike week of sunshine and warm temperatures, it looks like the weather will be getting a little more unsettled for the holiday weekend. A developing low pressure system over the Northern Plain states will bring an area of showers and thunderstorms into southern MB by Saturday night, with locally strong thunderstorms bringing a threat of heavy rain and hail to some localities. This activity will move east of the RRV into NW Ontario during Sunday, but another area of showers is forecast to spread in on holiday Monday along with cooler temperatures. The weekend won't be a total washout, with dry weather most of Saturday and parts of Sunday, but be prepared for the potential of locally heavy rain at times, especially Saturday night into Sunday morning.

Based on current models, here's what the weekend is looking like for Winnipeg and the RRV...

Saturday..Partly sunny, breezy. Chance of a shower or thunderstorm especially over western MB and Interlake. High 24.
Saturday night..Showers and thunderstorms developing. Some locally strong thunderstorms possible with heavy rain and hail.
Sunday..Showers and thunderstorms moving east then partly sunny. High 24.
Monday..Cloudy and cooler with showers developing. high 20.

More details as we get closer to the weekend. Stay tuned.

Friday, May 14, 2010

Fine stretch of summery weather ahead

After two weeks of below normal temperatures and unsettled conditions, the weather pattern will be shifting to a warmer and drier regime over the next week. Temperatures will be climbing into the mid 20s over the weekend into next week, with generally sunny skies and light winds. Normal highs for this time of year are around 20C so we'll be a good 5 degrees above that over the next week. Get out and enjoy it!

Sunday, May 09, 2010

Some rain tomorrow.. then a warming trend later this week

A band of rain over southern SK is forecast to spread into southern Manitoba tonight into Monday. The rain is expected to reach Winnipeg and the Red River valley Monday morning. General amounts of 5-10 mm are expected with this band of rain, with local amounts of 15 mm. The rain should move off Monday night with some lingering cloud and a chance of showers for Tuesday. Warmer and drier weather is expected for the latter half of the week, with 20 degree temperatures likely returning by the weekend.

Sunday, May 02, 2010

Snowflurries tonight?

After 2 days of rain, colder air is starting to sweep into southern Manitoba behind this storm system. Light rain continues over the Red River valley, but further northwest, rain has changed to snow over western Manitoba where there has been some accumulations north of Dauphin (see image here from Wellman Lake in the Duck Mtns) Winnipeg can expect to see additional light rain today into tonight with another 5 mm possible, but don't be surprised to see some flakes of wet snow overnight into Monday morning as colder air moves in. Accumulations are not expected here in the city, but there could be some areas that see a covering of slushy snow tonight into Monday morning. Another storm system tracking through the Prairies early this week is expected to bring more rain to southern Manitoba Tuesday, with wet snow possible again Tuesday night into Wednesday as another shot of cold air sweeps in. Welcome to May!

Saturday, May 01, 2010

April 2010 ninth mildest in Winnipeg since 1872

Ideal spring weather prevailed over southern Manitoba in April with warm and dry conditions for most of the month. The big story was the dryness, with no measurable precipitation recorded between the 3rd and the 27th. A storm system at the end of the month brought over 25 mm of much needed rain to Winnipeg and southern Manitoba, as soil conditions were becoming very dry in the prolonged dry spell. The month actually ended up with slightly above average precipitation (36 mm vs 31 mm), but that statistic fails to represent the extreme dryness experienced in April. There were frequent sunny days with low humidity, making for ideal conditions for outdoor activities. Every day of the month was above normal except one which was just below. The sunny dry weather helped boost the monthly temperature average to 8.3C at the airport, over 4 degrees above the normal of +4.0C. This makes April 2010 the 9th mildest in Winnipeg since records began in 1872, just behind April 1906 at 8.4C. (April 1915 stands as Winnipeg's warmest April with a monthly mean of 9.5C.) The warm conditions this month were prevalent over much of the eastern Prairies, northern Plains and Great Lakes regions which enjoyed one of the warmest and driest Aprils on record. (see map)

Overall, an ideal spring month with some beneficial rain at the end..

Rain eases dry spell over southern Manitoba

A major spring storm finally brought significant rainfall to all of southern and central Manitoba over the past few days bringing an end to the extremely dry conditions that had persisted over the area for virtually the past 2 months. Generally 20 to 40 mm fell across most of Southern Manitoba over the past 48 hours with a band of 40 to 65 mm across west central areas of the province.

The following are some of the higher rainfall amounts received
From Environment Canada and Manitoba agriculture sites over the
Past 48 hours up to 9 AM this morning.

Location rainfall (mm)

Ethelbert............ 66.0
Roblin............... 60.3
Swan valley.......... 53.0
Dauphin............. 50.4
Swan River.......... 44.8
Wasagaming........... 44.4
Eriksdale............ 43.6
Ste. Rose........... 43.2
Grandview............. 41.8
Moosehorn............. 36.8
Steinbach............ 34.6
Teulon............... 33.8
Dugald............... 33.6
Selkirk............. 33.2
Elm Creek............ 32.0
Starbuck............. 30.2

Winnipeg (Forks)........ 28.6
Winnipeg airport.......... 26.9
Winnipeg (Charleswood)......... 27.4