Tuesday, April 19, 2011

Stormy Wednesday

Dallas Morning News photo of wildfires creeping closer to the metroplex.

After a two day break in the weather more, cold, snow, freezing rain and sleet is forecast across the St Lawrence and Ottawa Valley tonight and Wednesday. Strong low pressure currently over the southern plain states will move rapidly northeast and down the St. Lawrence Valley. The system has a warm front in advance that will remain very close to Montreal tomorrow. Precipitation has already moved into southern Ontario in the form of showers and thunderstorms. The precipitation will overspread eastern Ontario after midnight and Montreal in the pre-dawn hours. Initially it will start as a mix of snow and sleet for Montreal before changing over to rain. A slushy coating to as much as 5cm is expected before the transition. Heavy Rain Warnings are in effect for the region with total amounts reaching 25-40mm. North of the valley snow is expected across the Laurentians and towards Quebec City where warnings are posted. Amounts may reach 15-25 cm with very strong winds up to 70km/h. Keep this in mind if you are travelling towards Quebec City. The same holds true for the Townships and Sherbrooke with less accumulation, perhaps 10cm. In Eastern Ontario a Freezing Rain Warning is in effect for the National Capital Region. Look for several hours of freezing rain and snow before a changeover to rain by noon. Across the upper Ottawa Valley and northeast Ontario look for snow to accumulate as much as 15cm.

Earlier in the week it appeared the storm would move well west of Montreal allowing the warmer air from the southern US to move in. Now with a track near or to the south of the city expect a cold chilly day with temperatures no better than plus 4C in Montreal and plus 1C to the north of the city. Winds will be gusty out of the northeast from 30-50km/h in Montreal and up to 70km/h in Quebec City.

TEXAS FIRES: The storm system is partly responsible for searing heat in Texas that has helped wildfires spread across the state. Close to 1 million acres have been charred with scores of fires burning out of control. Fires are even moving close to the Fort Worth and Houston metro areas. Drought this spring followed by the gusty winds and 90F heat has created very dry conditions and some of the worst fires in the history of the state.

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