Monday, January 23, 2017

Snowfall Warning for Montreal

The death toll has risen to 18 after tornadoes swept across the southeast US this past weekend. (AccuWeather.com)
Snowfall Warning in effect for metro Montreal, the Laurentians, and regions along the St. Lawrence Valley. Expect 15-25cm of wet snow and ice pellets Tuesday.

Heavy snow is forecast for southern Quebec Monday night and Tuesday, as a moisture laden system moves north along the eastern seaboard. The strengthening storm is part of the same system that launched deadly tornadoes over Georgia and Mississippi this past weekend. The death toll has risen to at least 18 after several major tornadoes swept the region. This included an EF-3 tornado, with winds in excess of 135mph near Albany, Georgia. Widespread damage was reported in several communities.

The storm will move north towards Cape Cod on Tuesday and then into Atlantic Canada by Wednesday. Snow mixed with freezing rain and ice pellets is forecast to begin this evening in southern Vermont and New York and spread north towards southern Quebec and eastern Ontario overnight. The bulk of the snow will fall Tuesday, with 15 to 25cm likely in southern Quebec. Less snow is expected south of Montreal, with more of a mix in those locations. Winds are increasing this morning out of the northeast up to 50km/h today and 60km/h in the snow on Tuesday. Temperatures will remain at or just slightly below freezing during the storm. Expect very poor driving conditions across out area for the Tuesday morning commute.

Sunday, January 22, 2017

Coastal storm to impact southern Quebec Tuesday

Low pressure will move along the east coast this week, producing heavy wet snow in Montreal. (AccuWeather.com)
A complex area of low pressure will move up the east coast early this week, with widespread precipitation and strong winds. Those of you who read this blog on a regular basis knew several weeks ago that the likelihood of a stormy end to January and equally wintry February was on the menu. It all starts this week with a rather difficult weather setup. Low pressure responsible for flooding in California and severe thunderstorms with deadly tornadoes in the southeast, will begin to redevelop just off the North Carolina coast. The storm will move north towards southern New England on Monday, and into Maine and Atlantic Canada by Tuesday. Montreal will be on the west side of the storm, with just enough cold air to produce wet snow. The snow will start late Monday evening and taper off by Wednesday morning. A mix of sleet, freezing rain and even some rain is possible as well, depending on your location. The air will be marginally cold enough for frozen precipitation, so we may bounce back and forth between snow and a mix. More snow is forecast from Montreal north and west, with a mix south and east towards the Townships and US border.

The same storm  forecast to bring Montreal snow this week, produced a tornado in Hattiesburg, Mississippi on Saturday morning. Widespread major damage along with four fatalities was reported. (AccuWaether)
I am expecting at least 15cm for Montreal, with as much as 25cm in locations that remain all snow. Temperatures will be around the freezing mark for the duration of the storm. Another factor with this low will be very strong winds, in excess of 50km/h in Montreal on Tuesday. Expect difficult travel around southern Quebec, into eastern Ontario including Ottawa, as well as extreme northern New York and Vermont. Weather warnings will be likely for heavy snow and freezing rain. The entire mess moves northeast by Wednesday, with mild air and few flurries or showers behind the storm. It will turn much colder by next weekend, more on that after the storm.

Friday, January 20, 2017

Mild weekend followed by potential storm for Montreal

A developing coastal low on Monday may provide heavy snow or freezing rain in southern Quebec by Tuesday. (AccuWeather.com)
The weather remains spring-like across southern Quebec this morning, with temperatures more like March than January. The low was 0C (32F) at my home on L'Ile Perrot, the normal overnight low should be -15C (5C). Skies remain dull this morning, and it should stay that way for most of the day. If we are lucky, a few breaks of sun may occur this afternoon. Temperatures will remain mild, up to 4C (39F). The weekend will feature more of the same, plenty of low clouds, some drizzle or freezing drizzle Saturday and very mild temperatures.

SNOWSTORM
Our attention then turns to early next week, and the potential for a significant storm Tuesday. Models have been consistently showing a low pressure area developing off the Carolina's on Monday and heading northward towards southern New England. Abundant moisture would be available with any coastal storm, what is missing is any sign of arctic air that would really ramp up this storm. That being said, marginally cold air would exist west of the storm track, enough to produce significant wet snow or freezing rain in some locations. The idea of a storm has been consistent from run to run of the weather models, what has not been, is the type of precipitation expected or the track of the storm. At this time, it looks like Montreal would receive wet snow Monday night and Tuesday, along with strong winds, in excess of 50km/h. Accumulations are difficult at best to pin down, but we could be looking at more than 15cm (6 inches) of snow in Montreal and points south and east, with lesser amounts as you head west into Ontario. A messy mix of freezing rain and snow would fall over northern New England, eventually transitioning to rain as you move southeast towards the coast.

I will post additional updates this weekend via The Suburban blog and Twitter account. Follow the forecast closely if you have travel plans late Monday through early Wednesday.

Tuesday, January 17, 2017

Mixed precipitation followed by warmer weather

Just some of the widespread damage from a weekend of freezing rain, power outages and accidents over Kansas and Oklahoma. The storm is now moving into southern Ontario and Quebec. (Weather Nation Photo)
Low pressure, responsible for a significant ice storm across the US plains and Midwest this past weekend, will move down the St. Lawrence Valley on Wednesday. The system will be weakening as it does so, transferring its energy to a second storm center developing off the New England coast. The coastal storm will move into Atlantic Canada through Thursday.

The result will be a swath of light-to-moderate precipitation, currently falling over southwest Ontario, advancing into southern Quebec by Tuesday evening. Additional snow from the coastal low will be pushed northwest into Vermont and northern New York. Slightly colder air will remain in Montreal as a result of northeast winds caused by the coastal low. Montreal, and southern Quebec can expect 5 to 10cm of mixed snow and sleet from this evening into early Wednesday morning. Travel will be affected, as roads become snow-covered and slippery. Freezing rain warnings are in effect in Ontario, between Kemptville and Kingston, for 2 to 5mm of ice accretion today. Warnings are also in place for portions of the Adirondacks and Green Mountains for heavier snow tonight. Temperatures will remain below freezing today in Montreal, before a notable warming trend starts on Wednesday. The balance of the week will feature well above-normal temperatures for Montreal.

Monday, January 16, 2017

January thaw expected from coast to coast

Milder Pacific air is expected to dominate the weather pattern from coast to coast in Canada, through at least the middle of January. (AccuWeather.com Map)
What has been a rather gentle winter here in southern Quebec will continue this week, with a pronounced January thaw forecast. Mild Pacific air is forecast to dominate the balance of the month of January from coast to coast, with the arctic air briefly retreating back north. High pressure is in control to start the week, with sunshine and mild temperatures of 1C (33F) forecast for Montreal. The normal high for January 16 should be -6C (21F), with a normal low of -15C (5F).

Before the thaw arrives in full force, we will have to deal with low pressure and a warm front that have been producing widespread freezing rain across portions of the US plains. The ice storm has caused power outages and numerous accidents from Oklahoma into Kansas. The front will arrive late Tuesday, with a messy mix of snow and freezing rain. Amounts may warrant advisories or warnings, but none have been issued at this time. Temperatures will be mild throughout the upcoming week, with highs generally from plus 1 to 4C (33 to 39F), and overnight lows from -3 to -5C (23 to 27F). Once the precipitation ends on Wednesday, we can expect partial sunshine and warm temperatures well into next weekend. Enjoy the break from the winter cold, because indications are that February will be much more winter-like than the previous months so far this season.

Some of the large "parking lot" piles of snow around the city, like the one shown above in St. Laurent, will begin to melt a little this week. (ValleyWX)

Monday, January 09, 2017

Another messy winter storm for Ontario and Quebec

Low pressure will move across the central Great Lakes and towards James Bay on Tuesday. (AccuWeather)
Another winter storm is taking aim at southern Quebec and Ontario late this evening. As with most of the storms so far this winter, the system will be passing well north and west of Montreal. This will place the entire region on the warm side of the storm. Monday was very cold across southern Quebec, with the morning low here on L'Ile Perrot at -23.4C (-10F). The cold air remained with us for the entire day, but should moderate overnight and Tuesday. The temperature will rise above 0C on Wednesday in Montreal, and may be as warm as 5C (41F) on Thursday.

 Low pressure will move across the upper Midwest and into the central Great Lakes. An elongated warm front will approach southern Quebec on Tuesday, with snow developing by afternoon and persisting to around midnight. A quick 5 to 10cm is possible in Montreal, with greater amounts north of the city. Precipitation will mix with rain late Tuesday night before tapering off on Wednesday. Widespread winter storm warnings and winter weather advisories are currently in effect for southern Quebec, Ontario and northern New York. No warnings have officially been posted for Montreal.

Another factor with this storm will be very strong  south and southwest winds. The wind will increase quickly on Tuesday and gust to 70km/h in the St. Lawrence Valley. Even stronger winds, over 90km/h, are possible in the Richelieu and Champlain Valleys. Yet another storm will arrive Thursday, with more rain forecast for Montreal, before cooler air arrives Friday.

Thursday, January 05, 2017

Storm leaves thousands without power in Quebec

Sanding on L'Ile Perrot Wednesday afternoon, after close to 15mm of freezing rain and 10cm of wet snow fell. (Valley Weather Photo)
A fierce combination of freezing rain and heavy wet snow, followed by winds in excess of 80km/h, have left thousands without power in southern Quebec. The winter storm dumped nearly 20mm of ice on the region, followed by as much as 15cm of wet snow. Close to 70,000 homes were left in the dark, most north and west of Montreal. Hydro Quebec has been working around the clock, with nearly 300 crews on the job. This morning the number is down to 35,000 customers. That amount was actually lower before a potent cold front arrived last evening. The utility expects most homes to be back online by the end of today. However, that will depend on new outages caused by the strong winds. Winds in southwest Quebec have been gusting from 50 to 70km/h. A peak gust of 86km/h (52 mph) was reported at Trudeau Airport, and 85km/h at St Hubert. The winds will eventually back off today below 40km/h by noon. The strong winds are generating intense snow squalls off Lake Ontario, some of which may meander down the St. Lawrence Valley. We may see more scattered flurries today, with a couple of centimetres of snow possible. If you have travels along Highway 401 towards Kingston, keep this in mind. Heavy snow squalls are likely with snow covered roads and reduced visibility.

Much colder air has arrived as well, -9C (16F) with a windchill of -19C (-2F) at 7 A.M. The colder weather is with us into the weekend, in some cases dropping below -20C. By the middle of next week, another storm will arrive, unfortunately with another messy mix of rain, freezing rain and snow.