Tuesday, December 31, 2024

Happy New Year!


With just a couple of hours to go in 2024, the year will end above freezing. The current temperature is 3.1C (38F) on Ile Perrot, we will not drop below 0C (32F) before midnight. A fitting end to what will likely be one of the warmest years on record for southern Quebec once the numbers are processed.

Precipitation is moving east across central Ontario currently and should arrive in the Montreal region during the pre-dawn hours New Years Day. Expect a messy mix of rain and snow throughout the day, along with dropping temperatures and increasing winds.

Have a very safe and happy new year, be kind to each other. Thank you for reading Valley Weather for the last 20 years...Stephen

Snow and cold return to Montreal to start 2025

While Christmas Eve was snowy and cold in Montreal, New Year's Eve looks more like early November. The record warmth of Monday has virtually eliminated all our snow in just a few hours. More snow is on the way however, as the weather pattern turns much colder and stormy to start 2025.

Happy New Year! 2025 will mark the 20th Anniversary of the Valley Weather Blog and the 46th year for Valley Weather. There was plenty of weather to talk about in 2024, none bigger than the billions of dollars in flood damage that occurred in Quebec from the remains of both hurricanes Beryl and Debby.

The year will end on a very mild note, we are currently 6C (43F) here on Ile Perrot, warm, but far from the 1875 record of 12.2C (54F). We did have a significant record high on Monday, reaching 11.4C (53F) at Trudeau Airport shattering the 2022 record of 8.6C (48F). Most of the snow cover has melted away, with the exception of a few patches here and there.

Winter will return however as we have a major pattern change on the way to begin 2025. It starts with deepening low pressure passing to our south across New England on New Year's Day, delivering steady precipitation across southern and eastern Ontario and Quebec. The storm will then head into Atlantic Canada.

The precipitation will start off as a messy mix of rain and snow, but as temperatures drop on Wednesday afternoon, all precipitation will change to snow. The snow will persist into Thursday morning, along with increasing winds out of the northwest and dropping temperatures. Accumulations will range from 5-10cm in valley locations to more than 15cm across the mountains of the Townships, Beauce, New York and New England. If you have travel plans on New Year's Day, expect highly changeable conditions with mixed precipitation and reduced visibility at times.

Look for windy, cold weather along with isolated flurries into the first weekend of the new year. Lows will drop into the minus teens, with daytimes highs struggling to rise above -10C (14F). The cold air will be with us well into the month of January.

Monday, December 30, 2024

Record warmth to end 2024 - winter will return this week

Before temperatures warmed Sunday evening, motorists were greeted with icy and foggy conditions late Saturday into Sunday morning. Since then however, temperatures have surged into the low teens in southern Quebec, and most of the snow on the ground has melted. Much colder weather returns by Thursday. (Valley Weather Photo)

A warm front finally lifted north of the St. Lawrence Valley early Monday morning, allowing very warm air to surge into southwestern Quebec. Granby reached 14C (58F), the warmest location in Canada, while Montreal settled in at 11C (52F), a new record high for the date, surpassing the previous of 8.6C (48F) set in 2022. Temperatures will slowly fall through the rest of the day Monday. Gusty winds are expected to develop, up to 50km/h at times.

After what was a very warm year, it is no surprise that we will end 2024 above freezing. While a cool front is on our doorstep this morning, temperatures are expected to remain well-above normal, right into New Year's Day. The weekend freezing rain and fog has dissipated, and now warm southwest winds and rain are eating away whatever snowpack was left in Montreal. Over the last few hours, we have recorded close to 10mm of rain.

This is a good time to remind everyone to stay away from area lakes and rivers. The ice is thin, unstable and dangerous, and the water is frigid and moving quickly.

As far as practical weather goes, we can expect showers to persist off and on through New Year's Eve, along with dropping temperatures. Temperatures should remain above freezing through Wednesday. By mid week, low pressure will develop along the east coast and draw in much colder air into Montreal, along with a swath of snow across our region. Depending on how fast we cool down here in the St. Lawrence Valley, we may be looking at 5-10cm of snow on the ground by Thursday morning.

The snow will be followed by an arctic blast that will plunge temperatures below freezing across much of eastern North America. The extended forecast for January across most of southern Ontario, Quebec and New England, is for cold and snowy conditions, perhaps a more typical Montreal January for a change.

Time will tell...

Thursday, December 26, 2024

Wet and warm weather forecast to end 2024 in Montreal

Boxing Day morning was spectacular but chilly in Montreal, with frost painted trees against a vivid blue sky here in the St. Lawrence Valley. (Valley Weather) 

Happy Holidays to everyone no matter what you are celebrating this week. For me, it has been a perfect Christmas holiday so far, with nearly ideal weather conditions for anyone who loves snow at this time of year. The fresh 10-20cm that fell on on Christmas Eve was followed by cold conditions, allowing for outdoor activates such as skating, skiing or sledding for the first time during the holidays in a few years.

At the same time, driving conditions have been good over the last 48 hours, with the exception of some isolated valley fog as well as a few slick spots on bridges and elevated surfaces especially late overnight and during the early morning hours.

We have had a temperature inversion here in the St. Lawrence Valley, which has meant colder air has been trapped at the surface while it warm air streams aloft at higher elevations. This has resulted in poor air quality here in Montreal at times, with a smog warning in effect for the city. Temperatures have dropped into the minus teens overnight, only rising to around -8C (18F) during the day.

We have one more day of these wintry conditions, before high pressure drifts east and is replaced by a series of warm fronts and low pressure systems. The first system on Saturday will produce warmer temperatures along with spotty freezing rain. By Sunday and into New Years Eve, temperatures will rise well above freezing, perhaps as warm as 6C (43F), accompanied by a decent amount of rainfall. Amounts may exceed 25mm (1 inch) here in Montreal.

By New Years Day and the start of 2025, colder air returns along with mixed precipitation at times. More details to follow. For now, you may want to clear downspouts of snow and ice in anticipation of the heavy rain expected Sunday and Monday.

Tuesday, December 24, 2024

White Christmas for southern Quebec and eastern Ontario

It was a perfect Christmas Eve morning walk with my pup here on Ile Perrot this December 24. Light snow was falling, adding to the 10cm or so that already accumulated overnight. The snow has now ended, and we can expect a dry and chilly end to the week for any holiday travel plans. Precipitation returns by the weekend, along with much warmer temperatures. (Valley Weather)

If you are an outdoor enthusiast, or just nostalgic for snow at this time of year, then you will be happy with the 12 to 15cm of fresh snow that fell across southern Quebec over the last 12 hours. Ottawa reported 17cm with Mirabel measuring 7cm. The snow was fairly light in nature, but still enough to cover roads and make travel slippery overnight. There were numerous incidents reported by police along the 417/40 corridor to Ottawa.

The low pressure responsible for the snow has moved rapidly into the Gulf of Maine Tuesday afternoon, with all warnings now dropped and precipitation over. Skies will remain mostly cloudy this afternoon and into Christmas Day, with a few breaks and light northerly winds. The high today will be close to -6C (21F), dropping to -16C (3F) overnight, and remaining chilly on Wednesday, at -10C (14F).

High pressure will move across the region, but an inversion will keep plenty of cloud cover in the valleys. By the weekend, we expect our next weather system to arrive in southern Quebec, along with warming temperatures and the threat for mixed precipitation.

If you have travel plans for Christmas or Hanukkah over the next 24 to 36 hours, roads should be in good shape. There me be a few icy spots around, especially secondary roads. Please travel with care and be courteous to fellow drivers.

Have a safe and happy holiday.

Sunday, December 22, 2024

Winter weather travel advisory in effect for Montreal

Environment Canada has issued a winter weather travel advisory for the St. Lawrence Valley, including metro Montreal for 10 to 15cm of snow Monday night. The snow will make for very poor travel conditions, with snow covered roads and lowered visibility. Conditions will improve during the daylight hours on Tuesday. Christmas Day is forecast to be sunny and cold. (Transport Quebec)

Widespread winter weather advisories have been issued for portions of Ontario and southern Quebec. Those weather warnings include the St. Lawrence Valley and metro Montreal. An Alberta Clipper low pressure system is expected to cross the Great Lakes and travel south of Montreal on Monday night. A swath of steady snow will spread southeast across eastern Ontario on Monday, and reach Montreal after 8pm. The snow will be moderate at times, persisting into Tuesday morning.

We can expect a decent 10 to 15cm of snow from late Monday evening into the Tuesday morning commute in Montreal, with 5 to 10cm expected elsewhere across southern Quebec. As much as 20cm could fall in the Ottawa Valley. For that reason and the fact the snow is coming during the start of the busy holiday travel period, the advisories were issued. Roads will become slippery and in many cases snow covered. Temperatures will remain cold with this system, so the precipitation will remain as snow for the duration of the event. Highs will be -5C to -7C Monday and Tuesday, with morning lows in the minus teens on Christmas Day. 

Travel conditions will be poor areawide Monday night, but will improve rapidly from west to east on Christmas Eve Tuesday.

Winter arrived in the pre-dawn hours Saturday, and along with it came the coldest air of the season. The morning low in Montreal on Saturday was -15.9C (4F), dropping to -17C (2F) Sunday morning. Gusty west winds produced wind chill values in the minus 20s at times Saturday.

We expect another cold night Sunday into Monday morning, as arctic high pressure crests over the region. If we reach -18C (0F) or colder Monday morning, it will be the lowest temperature recorded since February 25, 2023 when Trudeau Airport dropped to -20.4C. During the entire winter of 2023/2024, Trudeau Airport did not report one low temperature at or below -18C (0F).

Skies should clear out on Christmas Day, with sunshine forecast, but cold highs near -10C (14F). Temperatures will moderate for the balance of the week, reaching the freezing point by the weekend.

Thursday, December 19, 2024

Winter weather returns to Montreal to start the holidays

A clipper system brought a slushy 1-3cm of snow to southern Quebec on Wednesday evening. Another shot of snow Friday, followed by the coldest air of the season, will likely result in a white Christmas for Montreal. This has been rather difficult to obtain in recent years, with six of the last ten years officially green at Trudeau Airport. Environment Canada defines a white Christmas as at least 2cm of snow on the ground at 7AM on December 25.

Expect another shot of light snow for Montreal late Friday into early Saturday, followed by the coldest air of the season to date this weekend.

With Christmas and the holidays right around the corner, colder weather is on the way as early as Thursday. But will it last?

The reality of the fall and winter season this year as it was in 2023, is that we cannot sustain cold air for very long. The result has been above to well-above normal temperatures, interrupted by a day or two of cold weather.

We experienced that this week, with the coldest air of the season to date arriving last weekend, followed by temperatures soaring to nearly 8C (48F) on Tuesday, with rain. So far this month, as a result of the mild temperatures, we have had 46.8mm of rain, with only 24.2cm of snow falling at Trudeau. Only a trace of snow fell in the city in November. Very little remains on the ground.

That brings us to the current forecast and any hopes for a whiter Christmas. A clipper system moved south of the province on Tuesday, with a messy mix of rain and snow in Montreal. In the end, a slushy 1-3cm of snow fell, that has since frozen Thursday morning as temperatures fall quickly behind the system. We will drop to -8C (17F) late Thursday afternoon, and -12C (10F) by Friday morning.

WINTER SOLSTICE

Winter officially arrives at 4:21 AM Saturday morning, and with it will be coldest air of the season so far as temperatures drop to -18C (0F) or colder for morning lows and struggle into the minus teens for daytime highs. The cold will be accompanied by gusty northwest winds and biting windchill values. On Friday, we can expect another 2-4cm of snow as a second clipper system slides to the south of Montréal.

This low will eventually merge with a developing coastal low bringing Atlantic Canada a significant storm.

For Christmas and the holidays, southern Quebec can expect a warming trend once again, with highs approaching the freezing point in Montreal by Boxing Day. While no major storms are on the horizon currently, there will be some nuisance precipitation for most of next week.

Tuesday, December 10, 2024

Heavy rainfall warning posted for southern Quebec

An icy glaze coats the trees and roads early Tuesday morning after close to 9mm of mixed precipitation fell on the Montréal region overnight. More rain is on the way over the next 24-36 hours. (Valley Weather Photo)

Freezing Rain Warning through 11AM.

Heavy Rain Warning Wednesday.

Storm one is nearly done for Montreal, storm two is on the way.

We still have some very light freezing rain and drizzle around southern Quebec Tuesday morning, making for a slippery commute. Late Monday and overnight, close to 9mm of precipitation fell on the city, first as snow and blowing snow, followed by freezing rain since midnight. Temperatures remain stubbornly below freezing in the St. Lawrence Valley, currently -2C (29F) here on Ile Perrot. The freezing rain should end by noon as temperatures warm to a high of 4C (39F).

A heavy rainfall warning goes into effect this evening for Montreal and the Eastern Townships, with flood watches across Vermont and parts of New England. Deepening low pressure will lift from the middle Atlantic states across New Hampshire and into southern Quebec on Wednesday. The storm will draw in deep Atlantic moisture, producing heavy rain across our regions. The combination of heavy rain, melting snow and frozen ground, will create significant runoff and rises in area lakes and rivers. At this time 25-50mm is forecast through early Thursday. As the storm moves north of our region, cold air will filter in chaning any leftover rain to snow. A few centimetres are possible.

As temperatures drop on Thursday, we can expect very icy conditions. In addition to the heavy rain, winds will begin to increase, especially on Thursday, gusting up to 70km/h at times.

Monday, December 09, 2024

Stormy weather week ahead for the St. Lawrence Valley

Between 10 and 20cm of snow fell across the Montreal region Saturday night and early Sunday morning as the first widespread storm of the season moved across southern Québec. After a breezy, cold Monday, more snow, freezing rain and rain is on the way for the balance of the work week.

Expect difficult driving conditions at times this week, with a wide variety of precipitation and highly changeable temperatures across the region.

We can expect a brief break on Monday between the 10 and 20cm of snow that fell over the weekend and our next storm system rapidly on the horizon. It will be a very stormy week here in southern Quebec. The temperature roller coaster will persist as warm and cold air continues to battle over our region. After a cold, windy day Monday, with a high of -5C (23F), temperatures will rise on Tuesday, well-above freezing to 4C (39F).

Before then however, we can expect a burst of moderate snow right around the evening commute Monday, as a warm front lifts northeast across the region. The snow will certainly have an impact on the rush hour drive in Montreal, with as much as 5cm of snow this evening. As temperatures rise overnight, the snow will mix with and change to freezing rain in the St. Lawrence Valley, with a couple of millimetres of ice accretion possible. The freezing rain will taper off to showers Tuesday morning. Expect icy roads for the Tuesday morning commute.

Streets were snow covered across the Montreal region in the pre-dawn hours Sunday morning, but quick work by Transport Quebec and contractors, as well as milder temperatures Sunday, quickly melted the snow from most roads.

On Wednesday, a more impactful storm system is forecast to develop along the eastern seaboard and deepen rapidly as it moves north across New England and into Quebec. Heavy rain is forecast, with as much as 25mm for many locations in southern Quebec including Montreal. Temperatures will be very mild with the system, up to 5C (41F), so expect lots of melting and ponding of water. Some minor flooding is possible, especially south and east of the city and across Vermont and parts of New York State.

Further west in the Ottawa Valley, less rain is expected, but more snow may fall as that region drops below freezing earlier on Wednesday.

Another component of the storm will be strong winds, gusting up to 70km/h at times. As the storm moves northeast of Montreal, a strong cold front will sweep east bringing much colder temperatures along with a rapid freeze as any leftover rain changes to snow Wednesday night.

Thursday will be windy and colder with clearing skies, a brief break again before yet another storm arrives next weekend with more precipitation.

Saturday, December 07, 2024

Another round of snow for Montreal & southern Quebec

Winter driving conditions are back across southern Quebec and the Montreal region, with another 10-15cm of snow forecast Saturday night, followed by more snow and freezing rain for the week ahead.

Winter Weather Advisories are in effect for the Ottawa and St. Lawrence Valley, with snowfall warnings for the Laurentians and Gatineau regions.

A potent Alberta Clipper will move across southern Quebec late Saturday into Sunday morning, with a quick burst of moderate snow. The snow is already spreading across eastern Ontario and should arrive in southern Quebec over the next few hours. Expect a quick 10cm of snow for most locations, including Montreal, with as much as 15cm across the Laurentians and Ottawa Valley.

Roads will become snow covered and slippery Saturday night, and visibility will lower to under a kilometre or two in moderate snow at times. Expect conditions to improve Sunday morning as temperatures rise close to the freezing point and precipitation tapers off to drizzle. 

The weather will remain very active this week, as several storm systems and frontal boundaries traverse the region. We are looking at a messy mix of precipitation across the area, with more snow, freezing rain and rain likely. The time frame to watch for mixed precipitation will be late Monday and again Wednesday evening. The entire mess will freeze up Thursday behind a cold front as temperatures drop.

Winter driving is certainly back so plan for a slippery week ahead at times, starting Saturday evening.

Thursday, December 05, 2024

Finally the first snow of the season for Montreal

A snowy scene along Senneville Road after the first snowfall of the season on Thursday morning.

Snow has finally fallen across the Montreal region, with between 5 and 10cm accumulating for most locations in southern Quebec since late Wednesday. The snow was wet in nature, mostly falling overnight and into the Thursday morning commute. This guaranteed long travel times to work for many, with it taking no less than 45 minutes for me just to leave Ile Perrot this morning.

Plows and salters have done the job, and mild temperatures are helping melt the snow on most primary roads. However as temperatures drop this evening and winds increase, I expect we will have some slick spots around southern Quebec for the afternoon commute into the evening hours.

The snow has tapered off for the moment, as low pressure skirts along the international border and towards Atlantic Canada today. Temperatures are rather mild in Montreal, and should remain close to the freezing point for most of the day. A potent arctic boundary will arrive later this afternoon, accompanied by some snow squall activity. While the precipitation should be brief in nature, there may be some moderate snow falling along the front.

The commute was long for many Thursday morning as the first snow of the season fell across the Montreal region.

Winds will also increase along and behind the front, gusting in excess of 50km/h at times in Montreal. Temperatures are expected to fall quickly behind the boundary, down to -7C (19F) tonight, and remaining there on Friday. The end of the week will be cold and blustery, feeling like mid-winter, but it will be short-lived, with milder weather and even some mixed precipitation or rain returning by Monday.

The aforementioned arctic front is creating havoc across the Great Lakes region Thursday morning. Winds are gusting close to 100km/h across parts of northeast Ohio, Michigan, New York and Ontario, along with heavy snow and near-blizzard conditions at times for some.

Another round of lake effect snow will ramp up today into Friday, making travel difficult, if not impossible across several regions. This will impact Highways 401 and 403 in Ontario, as well as Interstates 81 and 90 in New York. Keep this in mind if you have travel plans south and west of Montreal. Some of the same locations that received over 100cm last weekend will be impacted again. The weight of the snow has caused damage to structures and trees across the lake effect zones.

Tuesday, December 03, 2024

Winter trying to return to Montreal - epic Great Lakes storm hammers NY & Ontario

A New York State Police vehicle blocks the entrance to a snow covered road in western New York, after an epic lake effect snowstorm dumped feet of snow on the region over the weekend. Montreal was left with only a few flakes around and little more. (New York State Police)

An Alberta Clipper type storm will skirt along the International border Wednesday into Thursday bringing gusty winds and the first significant snowfall of the season to Montreal.

While we are counting snowfall in flakes, parts of the Great Lakes were counting in metres! Over the weekend, arctic air flowing over the wide open and warm Great Lakes, produced epic amounts of snowfall to the south and east of the lakes. Off Lake Huron, close to 140cm of snow fell along provincial highway 11, stranding hundreds of motorists. The highway is slowly being reopened this morning after OPP and crews removed the abandoned vehicles. The weight of the snow also caused problems with power lines, trees and in some cases roofs of homes.

A dusting of snow on Ile Perrot Monday morning, as most of the lake effect remained well to our south and west over New York and Ontario.

Meanwhile south of the border it was much of the same from northwest Pennsylvania into western New York where 4 to 6 feet of lake effect snow piled up from Erie, towards Buffalo and along Interstate 81 in Watertown. There as well, thousands of cars and trucks were stuck for hours along the New York State Thruway.

More lake effect snow is on the way this week. While here in southern Québec, a few weak frontal boundaries, such as the one early Tuesday morning, have resulted in scattered snow showers. Depending where you are on the Island of Montreal, the ground may be white. The net result has been just a trace to perhaps a centimetre. Despite the light amounts, the nature of the snow falling on relatively warm surfaces, has created lots of black ice and the typical response from drivers. There have been many accidents across both eastern Ontario and southwestern Quebec since Sunday.

The bottom line, slow down, make sure you have winter tires on and that your windows are clear of snow and ice. Prepare for winter driving as we can expect accumulating snow Wednesday.

A quick moving low pressure system will move across the Great lakes and into southern Quebec on Wednesday. Mild, moist air flowing north along the track will result in a period of snow for the city starting late Wednesday. Montreal and most of southern Quebec can expect 5-10cm, with perhaps lose to 15cm locally. Accompanying the system will be gusty winds, up to 50km/h, producing some blowing snow, especially Thursday as temperatures drop behind the storm. Expect snow covered rods and slow commute times for Wednesday afternoon and Thursday morning.