Tuesday, April 14, 2015

Warm and windy Wednesday.. Burn ban in effect

A low pressure system tracking into southern Saskatchewan will bring a strengthening southerly wind across southern MB Wednesday , especially through Winnipeg and the Red River valley.  Southerly winds will increase to 40 or 50 km/h by mid morning with gusts to 70 or possibly 80 km/h by midday into the afternoon. The windy conditions will be accompanied by warm temperatures in the low 20s, and very low humidities of 15 to 20% leading to dangerous fire weather conditions.  Local grass or brush fires are possible, and a burning ban is in effect for much of southern and eastern MB. The strong winds may also lead to areas of blowing dust as dry topsoil gets blown around by the gusty winds.  Once winter snow cover is gone, April becomes a prime month for grass fires and blowing dust in the Prairies as strong gusty winds can combine with dry surface conditions to help promote fires and drifting topsoil. Increasing dewpoints, surface moisture, rainfall, and leaf/crop green-up in May and June help to reduce the threat of grass fires and blowing dust as the growing season progresses. However, grass fires can also flare up in the fall.. particularly in October at the end of the growing season and before the first snows of winter.

Thursday, April 02, 2015

Chilly start to April

Woodlands radar at 11:50 am shows
squall line of heavy snow heading
towards Winnipeg from the northwest 
Winnipeg about half an hour later. Visibility
dropped to near zero in heavy snow for about
30 minutes leaving about 2 cm of fresh snow
(photo from @kirastorm)
After a springlike first day of April that saw temperatures climb to 16C in Winnipeg, the weather turned decidedly winterlike today across southern MB as a sharp cold front sliced across the region this morning, ushering in a strong push of Arctic air today. The front was accompanied by periods of snow, including a band that tracked across the city over the lunch hour producing near whiteout conditions in heavy snow, as well as gusty north winds and temperatures near-5C. The band gave a quick coating of about 2-3 cm of snow that whitened the bare landscape. Skies cleared by late afternoon, but that will allow temperatures to drop to well below normal values tonight as an Arctic ridge of high pressure builds southward. Overnight lows of -14C are forecast for Winnipeg, some 10C below normal for early April. (it's been worse though.. record low for April 3rd is a frigid -27.8C in 1932)  Unfortunately, it looks like we'll be locked in a cold pattern into early next week before we start seeing some moderation towards normal values later in the week. That will mean daytime highs struggling to get above freezing or the low single digits over the next few days, with lows in the -10C range. Luckily, no major snowfall is expected during this cold snap, with only some minor dustings expected from time to time as weak systems pass through. Look at the bright side.. this time last year, we still had 40+ cm of snow on the ground, and we wouldn't see bare ground until April 20th!