Wednesday, February 22, 2023

Winter storm on the way for southern Quebec and Ontario

A poorly timed snow squall arrives along the western tip of the island of Montreal in Senneville late Tuesday afternoon. The squall lasted only 30 minutes, dropping a quick 2-3cm of snow and creating very poor road conditions slowing the evening commute right across the city of Montreal and beyond. (Valley Weather Photo)

Snowfall Warning in effect for Vaudreuil, Ile Perrot, Valleyfield, Cornwall, Ottawa

Special Weather Statement issued for Montreal

Winter Storm Warning for northern New York and Vermont

Wednesday morning is the calm before the storm in Montreal, with bright sunshine and cold temperatures. Widespread weather warnings and special weather statements are posted across all of southern Ontario, Quebec and neighbouring New York and New England in advance of a strong winter storm.

Strengthening low pressure will move from Kansas northeast across New York State on Thursday, followed quickly by a second area of low pressure Thursday evening. The combination of both storm systems will spread snow and freezing rain across southern Ontario today and into Montreal by midnight tonight.

Heavy snow falling just off Highway 40 in Senneville Tuesday afternoon.

After a sunny start to the day in southern Quebec, expect increasing clouds by afternoon. Highs will be chilly, around -5C (23F). The snowfall warning comes into effect this evening and overnight for southern Quebec. At this time it includes all regions from the St. Lawrence River south, but excludes the island of Montreal. Regardless of the warnings, look for snow overnight and Thursday, with the heaviest precipitation falling in the pre-dawn hours. Accumulations at this time are expected in the 10-20cm range for the Island of Montreal, 10-15cm north of the city and 15-25cm from the South Shore, including Vaudreuil and Valleyfield, south to the US border. Overnight lows will be cold, down to -12C (10F), combined with strong northeast winds up to 50km/h. The combination of wind and cold temperatures will allow for widespread blowing snow, especially off island.

Look for poor travel conditions overnight and Thursday morning. The snow may taper off early Thursday afternoon, before strengthening once again in the evening. The storm will finally move east on Friday, followed by frigid air into Saturday morning, with lows in the minus 20s. Temperatures will moderate on Sunday, but with additional snowfall expected.

I know March 1st is next week, in a perfect world the start of meteorological spring. However, keep in mind that historically in Montreal, late February and March usually produce our biggest snowstorms. The weather does look to remain active over the next ten days.

Tuesday, February 21, 2023

Snowy cold weather expected across southern Quebec

A quick moving front will delivery a round of snow squalls and flurries Tuesday afternoon, just in time for the commute in Montreal. Another more potent storm arrives late Wednesday, with a significant snowfall forecast for southern Quebec into Thursday.

Our active weather begins Tuesday afternoon, with the arrival of a cold front from Ontario. Along and ahead of the front, a brief burst of strong winds and heavy snow is expected, unfortunately just in time for the evening commute across the Island of Montreal. The squally weather will last less than an hour for most locations, with a quick 2-4cm of snow possible. Roads will become icy quickly as temperatures remain cold Tuesday afternoon.

High pressure will build in behind the front, with a cold night expected in southern Quebec, overnight lows will drop to -10C (14F). Wednesday will start off sunny, but clouds will be thickening and lower as an elongated warm front starts to lift northward across New York and Ontario. Along that front, a strong winter storm will move from the Midwest US into New York and New England during the day Thursday. The storm center will pass south of our region, with snow developing late in the day Wednesday in Ottawa spreading into Montreal by the early evening. Temperatures will remain quite cold along with increasing northeast winds. The snow will persist overnight into Thursday morning, with a potential 15 to 25cm expected for southern Quebec.

A strong winter storm will spread heavy snow and freezing rain from Montana to Nova Scotia over the next 48-72 hours. Southern Quebec is expecting 15 to 25cm of snow from late Wednesday into Thursday.(AccuWeather.com)

Gusty winds and cold temperatures will accompany the snow, along with areas of blowing snow possible as well. The storm will impact a large travel area from Ontario to Atlantic Canada and southward across northern New York and New England.

The system will be fuelled by arctic air to the north of the track and a surge of very warm air pushing northward from the southern US. Record warmth is expected across portions of Florida northward into the middle Atlantic states, while feet of snow will fall across portions of the Great Lakes, Upper Midwest and Northern Plains.

Weather warnings will likely be issued for Montreal. This post will be updated.

Thursday, February 16, 2023

Record breaking warmth to be replaced by snow across southern Quebec and Ontario

It did feel like spring had arrived, but Montrealers know better. Despite the rain and record warmth this week, snow is forecast to fall Thursday night across southern Quebec. The snow may mix with freezing rain at times, with 10 to 15cm forecast by noon Friday.

Montrealers witnessed a 141 year-old temperature record fall on Wednesday evening, when the mercury hit 9.1C (49F) at Trudeau Airport and 10.5C (51F) downtown. The previous benchmark for the day was 7.2C (45F) set at McGill University downtown in 1882. We also surpassed the Trudeau Airport record of 6.8C (44F) established in 2006. The surge of warm air impacted a large swath of eastern North America, with over 200 new daily temperature records established including Toronto and Ottawa.

Temperatures will remain above normal, but we have a significant change in the weather over the next 24 hours as a quick moving winter storm moves just south of the international border. The path of the low pressure has changed somewhat over the last 24 hours and so has the weather accompanying the system. Colder air is filtering into the St. Lawrence Valley, with Thursday's high of 7C (45F) reached at midnight, that was just shy of the 7.7C record for the date set in 1981. The updated track will result in more snow than rain for Montreal.

Thursday evening into Friday the strengthening storm system will move from Oklahoma to just south of Montreal and into Atlantic Canada on Friday. The storm will push a swath of deep moisture into the colder air across our region, with rain and freezing rain beginning after 6pm and changing to all snow this evening. The snow will end Friday morning for metro Montreal. Between 10-15cm of snow and perhaps a few millimetres of freezing rain are possible for the St Lawrence Valley. The temperature in Montreal will fall to -5C (23F) by morning, with a high of -3C (27F) Friday.

Widespread winter weather advisories have been posted along either side of the St. Lawrence Valley in Ontario and New York. In Quebec, freezing rain warnings are now in effect for the Richelieu Valley, with snowfall warnings posted in the Eastern Townships and Beauce regions for 15-25cm.

Skies will slowly clear Friday afternoon, followed by a cold night, down to -15C (5F).  The weekend is expected to be dry and mild at this time, with temperatures rebounding to near the freezing point or even above by Sunday.

Wednesday, February 15, 2023

Is winter over for Montreal?

The very mild weather over the past week has resulted in massive potholes opening up across many parts of the city and suburbs. The freeze/thaw cycle has been brutal. The weather over the next week or so will remain mild, with big temperatures swings from the overnight hours into the daytime, unfortunately the perfect recipe for even more potholes.

A Special Weather Statement has been posted for southern Quebec for a mix of freezing rain and snow Thursday night into Friday morning. Amounts will be determined based on the final track of the storm.

Is winter over for Montreal? The short answer is no. The days are certainly getting longer and the recent mild weather and melting snow has been a welcome relief after the frigid weather to start February, however we still have plenty of winter left. That statement will not be evident over the next 36 hours as very mild air streams northward into the St. Lawrence Valley, but a return to more seasonable temperatures and snowfall is anticipated by late next week. 

As I write this post, Montreal has already reached 5.5C (42F), close to the record high for the date set 141 years ago in 1882 at 7.2C (45F). A few showers are moving into the Montreal area along a warm front, but that will be followed by some breaks in the clouds Wednesday afternoon, and perhaps just enough sunshine to push us over the long-standing record. The normal high should be around -4C (25F).

In terms of practical weather, a compact area of low pressure will move well north of Montreal over the next 24 hours, bringing some clouds and light rain to the region. Gusty winds are also forecast, up to 60km/h at times. Above freezing temperatures will prevail through late Thursday evening, before the next system arrives.  This storm will be much stronger than the current, passing very close to Montreal overnight Thursday into Friday morning. Rain will develop late Thursday, changing to freezing rain and snow as colder air is drawn in from the northwest. Daytime highs will be mild today and Thursday, up to 7C, before a strong cold front arrives late Thursday. Temperatures will drop quickly through Friday morning, down to -5C (23F) in Montreal, rising very little on Friday. After very cold morning lows Saturday, warmer, quiet weather returns for the balance of the weekend, persisting into early next week.

Dangerous ice conditions

One more note on the mild weather of late, ice conditions remain highly variable at best and downright dangerous at worst. January was a very mild month, with nearly half the days in Montreal at or above 0C. February has been just as warm. The warm temperatures have resulted in a rise in area waterways helping to make the ice very unstable. Over the weekend, three individuals ice fishing on Lake Champlain in northern Vermont, died after falling through thin ice. My best advice would be to stay away from any body of water in the Montreal region and points south.

Wednesday, February 08, 2023

Mild weather to persist well into February for Montreal

A poorly timed snow squall along a frontal boundary made a mess of the evening commute across the western suburbs of Montreal on Tuesday afternoon. Several centimetres of snow quickly covered roads slowing traffic to a crawl on Ile Perrot and in Vaudreuil/Dorion. (Valley Weather Photo)

Special Weather Statement posted for southern Quebec for freezing precipitation late Thursday.

Freezing Rain Warning for the Ottawa Valley.

After the coldest 48 hours in decades, a much warmer weather pattern is becoming established to start the month of February. As I write, the current temperature in Montreal is 5C (41F). It feels like spring outdoors, with warm sunshine and melting snow. This is a far cry from Saturday morning, when Trudeau Airport recorded a record-breaking -29.5C (-21.1F). The previous record low at the airport was -28.9C set in 1963. The McGill record was -30.6C set in 1889. It was the coldest morning in 29 years since the -31.8C reading on January 27, 1994. The windchill was a frosty -44C, also a record for the date.

In contrast to our frigid weekend, January turned out to be one of the warmest on record across southern Quebec. The average temperature in Montreal was the 5th warmest on record for the city at -4.23C (24.4F). Records date back to 1872. The last time a January was this warm was back in 2002.

The arctic air is behind us now, and unlikely to return this winter. Looking ahead to the next 6 to 10 days, we can expect above normal temperatures, with several days well above the freezing point. A warm front Tuesday afternoon produced a brief period of heavy snow right around the evening commute, but it was short-lived. Warmer air has now arrived, with highs close to 5C today under fair skies. Wednesday night will feature clear skies, with mild overnight lows of -5C (23F). 

On Thursday, strengthening low pressure will pass west of Montreal allowing for warm air to remain in place. Temperatures will rise to 4C (39F) by late in the evening. Precipitation will arrive in the afternoon as wet snow, with 2-4cm possible before a transition to rain in the evening. A period of freezing rain is possible during the transition, especially north and east of Montreal and in the Ottawa Valley, where temperatures will be slow to rise above the freezing point. Plain rain will fall in Montreal, with 10-15mm possible. Strong winds are likely on Friday in advance of a trailing cold front, with gusts reaching 70km/h in the St. Lawrence Valley.

Precipitation may briefly change back to snow Friday night before ending by midnight. Saturday will be a fair, seasonably mild day as high pressure builds back into the region. The fair mild weather will be with us most of next week, with an extended period of above freezing temperatures allowing for some of the nearly 95cm of snow that fell on Montreal in January to begin melting.

Friday, February 03, 2023

Cold snap for 48 hours followed by significant warming trend

An icy sunrise over the St. Lawrence River near Ile Perrot. Extreme cold warnings are in effect for Friday and Saturday across most of Quebec.

Montreal is in the grips of some of the coldest air on the planet Friday morning, after a powerful cold front swept across southern Quebec late Thursday evening. The front was accompanied by snow squalls producing heavy snow and 70km/h wind gusts. Visibility dropped to near-zero across the Island of Montreal between 9 and 10pm. There were even reports of thunder and lightning on the South Shore.

All that is gone this morning, and we are left with intense cold. The temperature has dropped from -11C at midnight to -25C at 8am. Gusty northwest winds across the province are generating windchills in the -40C to -50C range. The cold air will continue to deepen today in Montreal, with temperatures actually falling towards -26C this afternoon and -30C overnight.

A fast moving arctic front produced wicked snow squalls Thursday evening. This was the scene in Terrasse-Vaudreuil off the southwestern tip of the island. Brief heavy snow, gusty winds and even lightning occurred with the frontal passage. (Video Image by Tammy Arbour) 

Hydro-Quebec is asking residents to conserve energy over the next 36 hours as the heart of the cold airmass resides over the province. The utility is expecting record demand today across the province.  The good news is that the cold outbreak will be short lived. High pressure will slide east late Saturday, allowing a warm front to lift into southern Quebec. After a cold Saturday with a high of -17C (2F), temperatures will warm all the way up to 2C (36F) by late Sunday. There will be some light snow mixed with, believe it or not, rain on Sunday.

The cold is affecting a large region. Widespread weather warnings are in place from Manitoba to Atlantic Canada and on the US side of the border from the Great Lakes to the Northeast and New England. According to Mount Washington Observatory Meteorologists, the icy cold will challenge the coldest temperature every recorded on the peak in New Hampshire of -47F. The overnight low into Saturday morning may be as cold as -50F with windchill values close to -100F. Mount Washington is known as one of the windiest locations on earth, and wind speeds are forecast as high as 140mph (225km/h) with this arctic outbreak.

Thursday, February 02, 2023

Extreme cold warning posted for Montreal

As if driving in from the off-island western suburbs of Montreal was not hard enough already with the bridge troubles, Wednesday mornings cold temperatures created ice fog and black ice on both bridges. Traffic was slowed to a crawl for the entire rush hour. The low Wednesday morning in Montreal was the coldest of the winter to date at -23.1C (-9.6F). It was -29.1C (-20.4F) in Vaudreuil-Dorion. (Valley Weather Photo) 

Extreme Cold Warning posted for metro Montreal.

Arguably the most famous Groundhog in the world, Punxsutawney Phil, has predicted six more weeks of winter. Time will tell, but one thing is certain, the next 48 hours will be extremely cold. The coldest airmass in several years is set to invade southern Quebec Thursday evening behind a powerful arctic front.

Extreme Cold Warnings are in effect for a wide area of southern and central Quebec, with windchill warnings posted across most of New York and all of New England. I expect weather warnings will be added shortly for eastern Ontario and the Ottawa Valley.

Most of Thursday will be fairly mild in Montreal, with scattered flurries. The cold front arrives late this afternoon across eastern Ontario and early this evening in Montreal. The front will be accompanied by a brief period of heavy snow and blowing snow, giving a quick 2 to 5cm at any one location. Strong winds will gust to 70km/h creating areas of blowing and drifting snow. Roads will quickly become snow covered and slippery.

The snow will end by midnight, followed by clearing skies and plummeting temperatures. The low tonight in Montreal will be -22C (-8F). Temperatures will continue to fall Friday, settling into the -25C to -28C (-13F to -18F) range for our area. Gusty northwest winds of 30-50km/h will persist all day Friday, creating dangerous windchill values of close to -40C. Temperatures that cold can freeze exposed skin within minutes. Postpone any unnecessary outdoor activities and be sure to dress in layers. Make certain your pets are indoors.

The cold will remain with us Friday night, with a low around -28C (-18F). Temperatures begin to moderate Saturday, along with increasing clouds and a high of -17C (2F). The warming trend continues into Sunday, with a high of -3C (27F) along with a few centimetres of snow.

Speaking of snow, January proved to be the second snowiest on record, just missing the 1999 record by 0.2cm. For the month, 94.8cm of snow fell at Trudeau Airport. Oddly enough, the 0.2cm we needed to tie the 1999 record fell before noon on February 1st, just a few hours too late.