Thursday, June 30, 2011

Steamy last day of June.. possible severe storms this evening?

It will be a steamy end to June as hot and muggy conditions spread over the Red River valley with temperatures climbing into the low 30s, and dewpoints in the uncomfortable 21-24C range. This will produce humidex values around 40C this afternoon which has prompted a humidex advisory to be issued for the RRV and southeast MB. Late today, a cold front will push through which may produce some strong to severe thunderstorms.. with large hail and damaging winds as the main threats. There is considerable uncertainty still as to if and where these storms will pop up.. so stay tuned today as the situation unfolds.

Monday, June 27, 2011

Warming up this week.. first 30C of the year likely by Thursday..

After a rather cool start to the week, things will be on an upswing this week as an upper ridge of high pressure builds over the Prairies. This will finally allow warmer air over the States to finally push northward into the southern Prairies, with the summer's first 30C readings likely by Thursday.. the last day of June. Before then, look for a cool night tonight as skies clear allowing temperatures to fall into the single digits by Tuesday morning. Tuesday will see sunshine with some afternoon clouds and afternoon temperatures of 22C. Southerly winds will be on the increase for Wednesday with gusty south winds of 40 gusting to 60 km/h pushing temperatures up to the 27C mark in Winnipeg. Thursday looks like the warmest day of the week with temperatures of 30-33C expected over southern MB.. including Winnipeg. If so, it will the first 30C reading of the year in Winnipeg.. almost a year to the day we reached our first 30C last year (a high of 30.2c on July 1st) A cold front will push through Thursday night with the potential for showers and thunderstorms, ushering in cooler but seasonable weather for the weekend.

Wednesday, June 22, 2011

Heavy rain over portions of Red River valley and southeast Manitoba

A storm system over the northern Plains brought an area of widespread rain over the Red River valley and SE Manitoba overnight into Wednesday morning, with some locally heavy bands of rain south and east of Winnipeg. In Winnipeg, rainfall amounts through Wednesday morning showed a significant north-south delineation across the city with about 5 mm along the north perimeter to 25 mm over the south perimeter.

Unofficial rainfall amounts through 11 am Wednesday morning (amounts since 6 pm Tuesday evening. Data from MB ag-weather, CWB Weatherbug and private stations)

Winnipeg stations..

North Perimeter ..... 6 mm
McPhillips ................. 10 mm
Charleswood ............ 12 mm
Whyte Ridge............. 18 mm
Oak Bluff .................. 19 mm
St Vital ..................... 20 mm
Brady Landfill .......... 25 mm
St Norbert ................. 29 mm

St Adolphe ................. 29 mm
Sanford ....................... 30 mm
Steinbach ................... 50 mm
St Pierre ..................... 51 mm
Morris ........................ 58 mm
Letellier ..................... 49 mm
Winkler ...................... 48 mm

Tuesday, June 21, 2011

Storm system over northern plains to bring rain to southeast Manitoba..

A strong storm system over southeastern South Dakota will track through Minnesota over the next 24 hours bringing a wide swath of rain over the North Dakota and northern Minnesota. The heaviest rain is expected to fall near or just south of the US border with totals of 25 to 50 mm by Wednesday evening. Some of this rain will spread into southeast Manitoba tonight into Wednesday with 15-25 mm possible over the southern RRV and southeast Manitoba (Steinbach, Sprague, etc) There will be a sharp cutoff on the northern extent of this rain shield.. which will likely set up roughly along the TransCanada highway. Little or no rain is expected north of this line, while areas to the south will see some precipitation, heavier as you go towards the international border. Winnipeg will lie on the dividing line with little or no rain expected north of the city.. and perhaps 5-10 mm just to the south Wednesday into Wednesday night.

Tuesday, June 14, 2011

Unsettled pattern this week..

Generally warm but unsettled conditions are expected over southern Manitoba this week as a large upper low pressure system settles over western Canada. This will put southern Manitoba in a southwest upper flow of unstable air through the rest of the week with periodic showers and thunderstorms as impulses move along the upper flow. Unfortunately, it looks like southwest Manitoba will bear the brunt of the heaviest precipitation during this period, with an increased chance of showers and thunderstorms the further west you go. The Red River valley will be somewhat drier with a mix of clouds and sunshine the rest of the week, and a chance of showers and thunderstorms each day. Due to the relatively slow motion of these storms, and the higher dewpoints advecting into southern Manitoba, rainfall will be very heavy with some of these storms, with local rainfall amounts of 25 to 50 mm, and in some cases higher amounts with training cells. This will put waterlogged SW Manitoba in a highly vulnerable situation depending on where the heaviest convection fires up.

Saturday, June 11, 2011

More rain on the way over southern MB..

It will be a nice start to the weekend today over southern MB with plenty of sunshine, light winds, low humidity and temperatures around 23C this afternoon. But in what is becoming an all too familiar pattern this year, the nice weather will not last long. A system pushing in from Montana will spread another round of showers and thunderstorms into southern MB Sunday, reaching SW Manitoba in the morning, and the Red River valley by late afternoon. General rainfall amounts of 10-20 mm are expected across southern MB Sunday through Sunday night into Monday, with thunderstorms bringing locally heavy rain of 25 to 40 mm in some areas. This will spell more bad news for the Souris and Assiniboine watersheds which are completely saturated and unable to take any more water. Wet weather will move into the Interlake regions Monday with generally drier weather for much of the upcoming week.

Wednesday, June 08, 2011

Another soaker for Southwest Manitoba..

As bad as this spring has been over the Red River valley, it's been even worse to our west. Southwest Manitoba and Southeast SK have bore the brunt of several major rain systems that have tracked across the Northern Plains states over the past 4 to 5 weeks. The result has been some amazing rainfall totals over SW Manitoba that have caused numerous problems with record high water levels on lakes and rivers, and a virtual wipeout of any crop this year for area farmers. Tuesday saw another 25 to 50 mm of rain across much of Southwest MB with the heaviest swath from the Virden area to Minnedosa where up to 55 mm was recorded. This is on top of at least 3 other major rain storms in the past 4 weeks that have brought 100-150 mm of rain over the area into the Interlake regions. In Souris, another 25 mm of rain fell yesterday bringing the total since May 1st to a whopping 216 mm, about 300% of normal.

Other rainfall totals since May 1st include.. (data from MB Ag-wx network)

Minnedosa............ 190 mm
Hamiota ............... 187 mm
Virden .................. 181 mm
Pierson ................. 175 mm
Brandon ............... 157 mm

A persistent storm track across the northern plains has resulted in a very wet start to the growing season over much of the southern Prairies, especially over southeast SK and southwest MB where over 200 mm of rain has fallen since April 1st (see map image left). In sharp contrast, things are very dry by the time you get over the central and northern Prairies with precipitation less than 40% of normal over central and northern Alberta (image right). (Maps courtesy of Drought Watch)

Thursday, June 02, 2011

Severe thunderstorms bring large hail and heavy rain over SW Manitoba, north of Winnipeg..

Severe thunderstorms affected much of southern Manitoba today as a warm front pushed north from North Dakota spreading moist and very unstable air ahead of it. Severe storms developed early this morning over SE Saskatchewan and SW Manitoba producing baseball size hail near Shilo and Hartney MB as well as very heavy rain. Storms moved into the Red River valley this afternoon, with a severe storm developing just northwest of Winnipeg around 2 pm. This storm brought golf ball size hail that produced extensive car damage (photos above) at the Bel Acres golf course just north of Winnipeg (see video of hailstorm) The storm continued northeast bringing large hail and very heavy rain to Stonewall, Tuelon and Winnipeg Beach areas. In Selkirk, the storm produced 37 mm of rain in only 20 minutes between 2:40 and 3 pm.

Severe thunderstorms affecting SW Manitoba this morning.. showers/tstorms spreading into RRV this afternoon into tonight

Severe thunderstorms have developed over SW Manitoba this morning in advance of a warm front pushing north from North Dakota. This front is pushing in very unstable air aloft which has triggered strong to severe thunderstorms with large hail and very heavy rain across SW Manitoba. Quarter to golf ball size hail has been reported in some localities with 25 to 45 mm of torrential rain falling within 1 or 2 hours, in areas that are still recovering from 50 to 75 mm of rain from earlier this week. The severe thunderstorms will continue this morning with additional showers and thunderstorms spreading into the Red River valley this afternoon into tonight. Some storms may continue to be severe with locally large hail and very heavy rainfall. Stay tuned..