Thursday, April 23, 2020

Record cold weather expected to ease this weekend

Snow flurries early Wednesday morning deposited a trace of snow along Highway 20 in the West Island. The light snow was enough to make roads a little slick in spots. The snow was part of an unseasonably cold airmass that produced record cold temperatures across eastern Canada. (ValleyWeather)
A strong cold front moved across southern Quebec late Tuesday ushering in record cold temperatures. The high on Wednesday was only 2C (35.6F) in Montreal, establishing a new record low maximum temperature for the date. The previous record was 3.1C (37.5F) set in 1993. The low early Thursday morning was -4.2C (24.4F), which was the second coldest April 23 on record dating back to 1945 when the mercury bottomed out at -5.6C (21.9F).

Overnight tonight into Friday morning, clear skies and calm winds should allow temperatures to reach record cold levels once again. The forecast low is -6C tonight in Montreal. The standing record for the date is -4.2C (24.4F) set in 1995. Ottawa also established a new record low this morning at -6.5C (20F), the previous low was -4.4C (24F) set in 1945.

Accompanying the cold air on Wednesday, were strong west winds gusting up to 70km/h. Windchill readings were as cold as -14C (7F) in Montreal. Snow flurries were also reported across southern Quebec, with minor accumulations occurring. A trace of snow was officially reported at Trudeau Airport, but the ground was white in a few suburbs around Montreal. More snow fell across the elevated sections of the Eastern Townships including Sherbrooke, where the high Wednesday was only -1.6C (29F).

Temperatures should begin to moderate slightly into the weekend with sunshine forecast Saturday and mix of clouds and sun on Sunday. The long-term average high for late April is 14C (56F) and the low 3C (38F).

Friday, April 17, 2020

April continues windy and chilly across southern Quebec

Snow showers on Thursday were part of an unseasonably cold and windy weather week in Montreal. The pattern of morning sun and afternoon snow flurries was repeated each day in southern Quebec from Tuesday through Friday. With the exception of Monday, temperatures were well below normal. (ValleyWeather Photo)
A cold and unstable air mass has settled over southern Quebec this week, with a similar daily cycle taking place. The early morning hours are sunny and cold, followed by thickening clouds and convective snow showers throughout the afternoon hours. The snow showers wane quickly after sunset, with the loss of daytime heating and instability. The pattern has been repeating itself daily since a strong cold front swept across Montreal late Monday. Temperatures have struggled to reach 6C (43F) each day, well below the normal high for mid-April of 12C (54F). Overnight lows have generally been below freezing, the normal low should be 2C (34F).

Accompanying the colder than normal weather has been decent snow showers, lowering the visibility at times. The snow has not amounted to more than a trace in the Montreal region, with a dusting at times north of the city. In addition to the the wintry precipitation, winds have been quite strong making it feel much colder. Peak wind gusts at Trudeau Airport this week were 102km/h on Monday, 76km/h on Tuesday, 61km/h on Wednesday and 63km/h Thursday. The snow showers have been less frequent Friday, but the weather remains blustery and cold, with west winds of 30 to 50km/h.

Friday night, Montreal will remain on the northern of a late season snowfall stretching from Chicago to Boston. Portions of southern New England are expecting 10-15cm of snow through Saturday morning. The low pressure causing the snow will move along the Pennsylvania/New York border and across southern New England.

High pressure will move into southern Quebec for the early portion of the weekend, with diminishing winds and slightly warmer temperatures. Highs both days should be near 10C (50F). The next chance for precipitation will be Sunday evening, as another potent cold front moves across Ontario and Quebec. Rain is forecast late Sunday, possibly ending as a period of snow early Monday morning. Cold temperatures will return to start the week.

Tuesday, April 14, 2020

Strong winds cut power to over 40,000 Quebec homes

A tree lies across Rue St. Denis in Montreal on Monday evening after powerful winds gusted over 100km/h. Over 40,000 Hydro-Quebec customers lost power as a result of the strong winds. Most were back online by the end of the day Tuesday. (Radio-Canada Photo)
A potent cold front swept across southern Quebec Monday afternoon, ushering in a few hours of strong west winds. Wind gusts reached 102km/h at Trudeau Airport during the evening hours Monday, with 96km/h recorded at Saint Hubert on the South Shore. The peak gust in Quebec was 124km/h at Riviere-La-Madeleine. In Ontario, winds gusted to 100km/h at Cove Island, with 81km/h in Toronto. The 102km/h wind gust at Trudeau Airport was very close to the all-time April record of 106km/h set in 1975.

All over Ontario and Quebec, the strong winds brought down tree branches and power lines. At the peak of the outages on Monday night, Hydro-Quebec reported over 40,000 customers without power. That amount was down to under 10,000 by Tuesday morning and near 3000 by the afternoon. Other minor structural damage was also reported across the city of Montreal.

The strong winds were preceded by heavy rainfall, with a record breaking 28.4mm falling at Trudeau Airport. The previous 24-hour daily record for April 13 was 23.6mm set in 2004. I measured 32.6mm on Ile Perrot. The rain was especially heavy along a late afternoon cold front, with some minor flooding observed.

Saturday, April 11, 2020

Next storm on the horizon for southern Quebec

The most recent Nor'Easter produced tidal flooding in parts of Quebec City. The same storm dumped up to 30cm of heavy wet snow along the Maine border. (Journal de Quebec)
There is plenty to talk about in the weather department tonight, with another strong spring storm expected to impact Ontario and Quebec late Sunday into early Tuesday.

Strong low pressure will move across the Midwest and into the Great Lakes, passing just west of Montreal on Monday. Heavy rain is expected across the region, along with some isolated thunderstorms. At this time, 25 to 35mm of rain is possible starting late Sunday and persisting Monday. Accompanying the rain will be very strong winds. Winds are forecast to increase in speed Monday afternoon, possibly reaching 90 to 100km/h in the St. Lawrence Valley. Winds that strong are capable of tree and power line damage. Warnings may be required.

Thursday's storm dumped up to 40cm of wet snow in Maine, bringing down trees and power lines. Hydro-Quebec has responded, with 60 trucks and 40 lineman currently in Maine assisting with the repairs. (Emera Maine Photo)
The most recent storm on Thursday, was a little less intense than expected for Montreal, however other portions of the province and parts of New England were hit hard. Montreal received 3cm of wet snow, along with 8.4mm of rain. Portions of the Gaspe, Beauce and Eastern Townships measured between 15 and 30cm of heavy wet snow. South of the border in Maine, conditions were far worse, with as much as 40cm of snow falling, along with strong winds. That combination resulted in power outages to over 250,000 residents, nearly 30 percent of the state. Hydro Quebec has sent 60 trucks and 40 lineman down to help Central Maine Power and Emera Maine to repair downed lines and power poles. The outage has been made worse by the ongoing Covid-19 Pandemic.

Parts of Quebec City received tidal flooding form the storm, with water several feet deep in sections of the Vieux-Port district of the city..

FLOOD POTENTIAL
The precipitation was enough to rise water levels slightly on Lake of Two Mountains and the St. Lawrence River. Lake of Two Mountains is sitting at 23.47 metres at Sainte-Anne-de-Bellevue, minor flood stage begins at 23.30 metres. Several West Island municipalities have started flood preparations including Saine-Anne-de-Bellevue, Pierrefonds and Ile Bizard. Sainte-Anne's has made pallets of sandbags available, with delivery beginning on April 16th. Other suburbs have been staging pumps and sandbags. The situation will need to be carefully monitored in the coming days, especially with the added rainfall.

Wednesday, April 08, 2020

Spring storm to deliver rain and snow to southern Quebec

Low pressure will move across New York and New England on Thursday while deepening rapidly. The strong spring storm will produce heavy rain in the valleys, and a snowstorm for many higher elevations. (AccuWeather.com)
A rapidly strengthening spring storm is forecast to move across New England on Thursday and into the Gulf of Maine. A wide swath of precipitation is expected to impact Ontario and Quebec starting Thursday morning. Most regions, including Montreal, will receive a cold rain on Thursday, with amounts of 15 to 25mm possible. Daytime high temperatures will struggle to reach 5C (41F) in Montreal, along with increasing northeast winds. The rain will mix with and possibly change to wet snow Thursday night as temperature fall to the freezing point. At this time no major accumulations are forecast for the city of Montreal, but the situation will have to be monitored closely. Winds are forecast to increase up to 50km/h Thursday night into Friday morning.

Regions to the east of Montreal, including the Eastern Townships and Quebec City, will receive a mix of rain and snow Thursday, changing to all snow late in the day, especially across the higher elevations. Quebec City and portions of the lower North Shore and Gaspe regions may receive 15 to 20cm of heavy wet snow by Friday morning. Upper elevations of the Townships and Beauce close to the Maine, New Hampshire and Vermont border may receive more than as 30cm of snow. Special weather statements are in effect for those regions, but they may be upgraded to warnings on Thursday.

Many municipalities are planning and preparing for the possibility of spring flooding, including the Borough of Pierrefonds-Roxboro. (Pierrefonds-Roxboro Photo)
The heavy wet snow could damage trees and power lines.The additional rainfall will also raise concerns for spring flooding.  Precautions are being taken in many southern Quebec municipalities, but no flood watch or warning is in place at this time. While water levels are stable at this time, they remain high due to spring runoff. Be vigilant near any waterways.

Unseasonably cold air will pour into southern Quebec behind the storm system for the Easter long weekend. Expect temperatures to be below normal through Sunday, with daytime highs near 5C (41F) and overnight lows around -1C (30F).

Thursday, April 02, 2020

April begins as March ended in Montreal, warm and wet

An empty Highway 20 eastbound near the Dorval circle during the Thursday morning commute. Two rare observations to note, first there is absolutely no traffic due to the Covid-19 Pandemic. Secondly, veiled sunshine, with clouds thickening and lowering from the east rather than the west, as a coastal storm system begins to impact the region. (Valley Weather Photo) 
Retrograding low pressure south of Nova Scotia will be responsible for increasing clouds and precipitation in Montreal on Thursday. Typically precipitation moves from west to east across the Montreal region, but every now and then we see it move up the Saint Lawrence Valley from the Atlantic Ocean. Rain will be the dominant form of precipitation in Montreal, but other parts of the province, including Quebec City, may see a little wet snow. The rain will begin this afternoon and persist into Friday. Winds will become gusty as well, from the northeast up to 50km/h. Temperatures will be relatively mild, with daytime highs in Montreal between 6C and 8C (43F to 47F) and overnight lows around 1C (33F).

MARCH SUMMARY
March was a very warm and wet month in Montreal, more springlike than anything. Typically we receive several major snowstorms over the course of the month in Montreal, but such was not the case this year. The city received a record breaking 129mm of precipitation, surpassing the previous benchmark of 115mm set way back in 1942. With the exception of a paltry 9cm of snow, the balance was rain. The reason most of the precipitation was in liquid form was due to the fact the temperatures ended the month well above normal. The average at Trudeau Airport was plus 0.7C (33.3F), significantly above the long-term monthly average of -2C (28.4F). We also experienced two thunderstorms in Montreal, not rare for March but certainly unusual. We started March with 20cm of snow on the ground at the airport, but most had melted away by the 15th.

The abundant rainfall combined with snowmelt has municipalities around metro Montreal on standby, and in preparation mode, but so far flooding has been minimal.

While southwestern Quebec was warm and wet, the eastern portion of the province was the exact opposite, cold and snowy. Temperatures in the Saguenay, Lower North Shore and Gaspe regions were actually below normal. Over 100cm of snow fell at Sept Iles during the month, with 114cm of snow still on the ground as of April 1st.

Sunday, March 29, 2020

Heavy rain and thunderstorms for Montreal

The storm system impacting Montreal on Sunday, produced multiple tornadoes on Saturday. A strong tornado hit Jonesboro, Arkansas, shown above, destroying homes and businesses and injuring at least six. (The Weather Channel).
Heavy rain warning in effect for metro Montreal and southern Quebec, as well as eastern Ontario, including Ottawa.

An strong upper level low will move into the Great Lakes Sunday and then eastward across Ontario and Quebec. The system will provide abundant precipitation to the region, with heavy rain and scattered thunderstorms forecast for Montreal.

The rain will begin early Sunday and persist into Monday. The risk of thunderstorms will be mainly across eastern Ontario, but a few may wander into southern Quebec. In terms of amounts, up to 50mm (2 inches) of rain will be possible in Montreal. The rain, combined with melting snow, may produce some isolated flooding in low lying areas. According to Public Security Quebec, most rivers in southern Quebec are currently below flood stage but are being closely monitored. The only exception at this time is Lac St Louis at Sainte-Anne-de-Bellevue, which is reported as being in minor flood stage. No flooding has been reported.

Strong winds will accompany the rain, gusting up to 60km/h in Montreal.Warm air will flood into parts of Ontario and New England, but a northeast flow will keep temperatures cooler in the St. Lawrence Valley. The high today will be around 6C (43F) in Montreal.

A small area of heavy wet snow will impact the St. Lawrence Valley northeast of Montreal, as well as adjacent portions of northern Maine and New Hampshire. (AccuWeather)
SPRING SNOW
Even colder air will move into the regions northeast of Montreal into Monday, with rain expected to change to wet snow. Quebec City and points north and east may receive between 10 and 20cm of snow. A special weather statement is in effect for Quebec City, with snowfall warnings in the Charlevoix region.

Colder air will eventually arrive in Montreal late Monday, with rain tapering off to a few flurries.

The same storm was responsible for severe weather across portions of the southern and central US on Saturday and early Sunday. Strong thunderstorms produced multiple tornadoes and hail in many locations from Arkansas to Illinois and points east. More thunderstorms are expected on Sunday from the Ohio Valley into the Northeast.

Sunday, March 22, 2020

Spring snow on the way for southern Quebec

Strong winds accompanied a cold front on Friday afternoon, gusting up to 100km/h in southern Quebec. The wind knocked out power to more than 12,000 customers across the southern portion of the province. (Hydro Quebec Photo)
After a bright, sunny and cold weekend, milder temperatures are on the way for Monday, along with some wet snow. The snow should begin late Monday and end early Tuesday, with only 1 to 3cm expected for Montreal.

A strong cold front crossed southern Quebec on Friday, along with the first thunderstorms of the young season. The storms were fast moving, sweeping the Island of Montreal around 3pm, accompanied by heavy rain, lightning and wind gusts to 90km/h. Rainfall was decent, but not as much as I had anticipated, with 16mm falling in Montreal. Friday was the warmest day of 2020 to date, reaching 16.4C (61.5F) in Montreal.

Behind the front, strong west winds persisted well into Saturday, accompanied by rapidly dropping temperatures. Saturday and Sunday were bright and sunny, but blustery and cold. It has been a rather mild March, which made daytime highs below freezing this weekend seem rather frigid. Overnight lows were down into the minus teens, with windchill values approaching -18C (0F).

Montreal will remain on the extreme northern edge of a a quick moving spring coastal storm that will dump as much as 25cm of wet snow on interior southern New England. (AccuWeather.com)
Warmer air is on the way as two low pressure systems slide south of our region. The first will bring a period of wet snow to parts of Ontario tonight and Monday. This system will then be absorbed by a stronger storm moving up the eastern seaboard. The low pressure will pass east of New England before impacting Atlantic Canada. Montreal will remain on the northern of the storm, with a few centimetres of wet snow possible from late Monday into the overnight hours Tuesday. Further south across New England, 5 to 15cm is possible, with 2 to 4cm in eastern Ontario. Most of the snow should melt on contact during the daylight hours, but some slick spots may develop late Monday night.

Skies will clear out Tuesday, along with mild daytime highs of 5 to 7C.

Thursday, March 19, 2020

Welcome to Spring 2020 - first thunderstorms of the season possible in Montreal

It continues to be a strange and difficult time for so many around the world and now right here in Montreal and across Canada. The rapid spread of the Covid-19 virus has meant lifestyle changes for all of us. I wish all my readers good health as we all continue to deal with this global Pandemic. Be safe and be good to each other.

March an be a nasty month, with historically lots of big snowstorms. This has not been the case in 2020, as only 3.4cm of snow has fallen at Trudeau Airport. On Tuesday morning, some brief steady snow put down a quick 1 to 2cm in Montreal, before temperatures warmed above freezing. (ValleyWeather Pic)
SPRING 2020
The one tiny bit of good news lately has been the weather. Spring officially arrives at 11:50 PM Thursday evening, the earliest arrival in 124 years. Thursday was very springlike in Montreal, reaching a high of 9C (48F) The entire month really has been rather easy, with all the storms travelling to our west, introducing mild air into our region. For that reason, to date, we have had only 3.4cm of snow at Trudeau Airport. The long-term average is 36.2cm. It has been a wet month, with 61mm of rain, and that tend will continue tonight and Friday. The normal rainfall for March is only 29.7mm

THUNDERSTORMS
Strong low pressure will lift across the central Great Lakes on Friday, lifting a warm front across the St. Lawrence Valley. A surge of warm air will accompany the front early Friday, along with a decent shot of steady rain. There is even the risk of a few isolated thunderstorms overnight, with an even greater risk in the afternoon along a potent cold front. Some of the storms may even reach strong to severe limits, with heavy rain and strong winds. Before the front arrives, temperatures will soar into the middle teens, possibly 16C (60F) in some locations across southern Quebec.

After a very warm day on Friday, temperatures will drop rapidly behind a potent cold front. High temperatures on Saturday in Montreal will be nearly 20 degrees colder than Friday. (AccuWeather.com)
The cold front will arrive in the afternoon, accompanied by showers and thunderstorms, as well as very strong winds, gusting from 50 to 70km/h. The front will clear the region late Friday. Temperatures will rapidly fall behind the front, down over 25 degrees from the daytime high, approaching -10C (14F) by Saturday morning. Rainfall amounts on Friday will be in the 15 to 25mm range in Montreal. North and west of the storm track, heavy snow and blowing snow is occurring, with as much as 20cm expected across far northern Ontario and central Quebec.

The weekend will be sunny and cold for southern Quebec and eastern Ontario, with daytime highs of 0C and overnight lows of -10C (14F).

Thursday, March 12, 2020

Another round of rain and freezing rain for southern Quebec

Another round of freezing rain is expected early Friday morning in parts of metro Montreal.
Freezing Rain Warning for Montreal and Laval: 2 to 4mm of freezing rain possible early Friday morning. 
Winter Storm Warning for Quebec City. 
High Wind Warning for the Richelieu Valley.

Low pressure will move across the Great Lakes and well north of Montreal over the next 24 hours. We can expect another round of rain and freezing rain across eastern Ontario and southern Quebec. A warm front associated with the storm will lift across the St. Lawrence Valley early Friday morning, rapidly followed by the cold front late in the day. Rain or freezing rain will start before sunrise Friday, changing quickly to rain in Montreal, as temperatures warm to 8C (47F). The rain may be heavy at times in Montreal, with 15 to 25mm possible. A mix of freezing rain and snow is likely northeast of Montreal for most of the day.

As we witnessed on Tuesday, the cold air can be stubborn to move out where northeast winds remain. That included northern portions of Montreal, Laval and areas northeast of the city towards Quebec City. Those regions once again will see the longest duration of freezing rain on Friday. Quebec City will even see a shot of heavy snow, with up to 15cm possible before the changeover.

Strong winds are also forecast to develop on Friday, gusting between 40 and 70km/h in Montreal, and up to 90km/h in the Richelieu Valley. The wind will ease somewhat late Friday, but it will remain breezy into Saturday morning.

Temperatures will begin to drop Friday evening, with any remaining precipitation in Montreal tapering off to flurries. Overnight lows will drop back to the freezing point by Saturday morning.

The storm on Tuesday, produced 12mm of rain and freezing rain in Montreal, with over 20mm of precipitation in Quebec City, including 22 hours of freezing rain.

Monday, March 02, 2020

Freezing rain warning for southern Quebec

A warm front will produce widespread rainfall over southern Quebec late Monday, along with pockets of freezing rain from Laval northward. Between 2 and 15mm of precipitation is forecast for the region.
Freezing Rain Warning for Montreal, Vaudreuil, Lachute, Laurentians and Lanuadiere.

An unsettled but fairly mild weather week lies ahead for southern Quebec. A warm front will approach the region this afternoon, along with a swath of rainfall. Some locations north of the St. Lawrence River will be at or just below the freezing point when the precipitation arrives, therefore Environment Canada has issued a freezing rain warning for Montreal, the Laurentians, Lachute and points north and east. Generally 2 to 5mm of freezing rain is expected, with local amounts approaching 10mm, especially in the Ottawa Valley. I think most of the precipitation will fall as plain rain in Montreal, however the ground is still cold enough from our recent chill, so icy spots are definitely possible, especially in suburban neighbourhoods. Temperatures today will reach 3C (38F) in Montreal, but should remain near 0C north of the city.

Precipitation will taper off to light snow this evening as slightly colder air filters into southern Quebec. The overnight low will be near -1C (30F).  We get to do it all over again on Tuesday, as the cold front stalls just south of Montreal, and weak low pressure moves along it. A mix of rain and snow is possible late Tuesday into the overnight hours. More unsettled weather is forecast to end the week.

 The good news as we take a brief look deeper into March, is that no arctic air is on the horizon. Dare I say we may be looking at a quick end to the winter that wasn't. I will take a more detailed look at winter 2019-2020 in a later post, but we can all honestly say, it was an easy winter. As February draws to a close, it was really the worst month of the season, with 67.6cm of snow measured at Trudeau Airport. Despite all the snow, we still managed above normal temperatures, with a daily average of -6.2C (20.8F). The long-term normal for the month is -7.7 (18.1F).

Thursday, February 27, 2020

Snowfall warning for Montreal

Expect highly variable travel conditions across southern Quebec today, with heavy snow north and west of Montreal, and rain along the US border.
Precipitation has been fairly light so far in Montreal, with just a centimetre of snow overnight. Radar shows heavy precipitation moving in form the south early Thursday morning. Look for a mix of wet snow and rain in Montreal for the morning commute.

Strong low pressure will move from upstate New York into the St. Lawrence Valley today. Heavy wet snow is falling west of Montreal in the Ottawa Valley, while a rain/snow mix persists in southern Quebec. All regions should change to snow by the middle morning hours, with the exception of regions along the US border and in the Eastern Townships.

Snowfall amounts will be highly variable with this storm, ranging from less than 5cm along the US border to upwards of 30cm across the Ottawa Valley, the Laurentians and into the Quebec City region. The wind will become a major factor later this morning, gusting up to 70km/h in the Montreal region, and as high as 100km/h along the north shore of Lake Ontario, and in the Quebec City region. Expect widespread blowing snow in regions where snow is falling. The winds should diminish this evening and overnight as the storm moves to the east of Montreal.

Temperatures will be very mild this morning in Montreal, up to 3C (38F). They should begin to drop by mid-morning, reaching -4C (25F) by the end of the day.

In the wake of the storm, heavy lake effect snow is forecast to develop around the Great Lakes. If you have any travel in this region through Friday, expect very poor driving conditions. Blizzard warnings are in effect for western New York, including the Interstate 81 corridor for those travelling south for spring break. Some of the stronger squalls may even reach as far as southern Quebec on Friday, but they should be light in nature.

Wednesday, February 26, 2020

Complex winter storm to impact Quebec & Ontario

A strengthening winter storm will move from the Ohio Valley towards eastern Ontario over the next 36 hours. Heavy snow mixed with rain is forecast to develop in Montreal late Wednesday. (AccuWeather.com)
Snowfall Warning for metro Montreal and the St. Lawrence Valley including eastern Ontario as well as Toronto and southern Ontario.
Winter Storm Warning for Quebec City, Ottawa and the Laurentians

Travel will become extremely difficult tonight and Thursday as heavy precipitation and strong winds sweep southern Quebec and Ontario. Widespread weather warning are in effect.

Low pressure developing over the Ohio Valley early Wednesday, is forecast to deepen and move towards Lake Ontario and the St. Lawrence Valley on Thursday. A warm front extending from the low, will lift northward towards southern Quebec overnight tonight. A very complex forecast is setting up, with temperatures just marginally cold enough for snow.

The low will split the region in half, with heavy wet snow north of the St. Lawrence River, into Laval, the Laurentians and Ottawa Valley. South of the storm track, likely including portions of metro Montreal, a mix of wet snow and rain will occur. Powerful winds will develop early Thursday morning with the precipitation, gusting up to 70km/h in Montreal and 100km/h in the Quebec City region. The strong winds will produce blowing snow in many regions, especially north and east of Montreal.

In terms of accumulations, amount will range from just a few slushy centimetres near the US border, to 15cm or more in Montreal, 25cm in Ottawa and as much as 35-40cm in the Laurntians and Quebec City. Even Toronto is in on the action this time, with up to 25cm forecast for parts of the GTA.

Temperatures throughout the storm will be either side of 0C (32F). As the low pressure moves off to the east late Thursday, much colder air will be drawn in on the back side of the system. Temperatures will drop into down to -8C by Friday morning. Precipitation will taper off to flurries on Friday.

Monday, February 24, 2020

Early taste of spring to be followed by another winter storm for Montreal

Our first taste of spring in Montreal this year, will be followed by a winter storm late Wednesday and Thursday. Between 15 and 25cm of snow is likely in southern Quebec, along with blowing snow. (AccuWeather.com)
Special Weather Statement in effect for southern Quebec and Ontario.

As I write this, the temperature just hit 10C (50F) at my home on Ile Perrot late Monday afternoon. Spring is in the air, with plenty of sunshine and lots of melting snow. Most regions across southern Quebec are reporting daytime highs between 5C and 9C (41F - 48F) today, well above the long term average of -2C (28F). Skies will trend party cloudy overnight, as a weak cold front slips south of the St. Lawrence Valley. The front will be dry, with no precipitation, but temperatures will drop, back below freezing by morning, at -1C (30F). On Tuesday, expect partly cloudy skies, still mild, but not as warm as Monday, with a high of 4C (39F).

That ends the good news in the weather department. Complex low pressure if forecast to develop over the southern US on Tuesday and move northeast towards the Ohio Valley by Wednesday. The strengthening storm system will then move across southern Ontario and into Quebec. Secondary low pressure may develop along the east coast, complicating the forecast. At this time, a mix of rain and snow is forecast for Montreal.

Precipitation will start Wednesday across southern Ontario and during the evening hours in southern Quebec. Light rain will develop in Montreal and mix with snow after midnight. Precipitation will change to heavy wet snow by early Thursday morning. At this time, we are looking at 10-15cm for Montreal, with the bulk falling during the Thursday morning commute. More snow is forecast north of the city into the Laurentians and Ottawa Valley, where up to 25cm is possible. Precipitation will be accompanied by gusty winds, up to 60km/h. Travel is likely to be impacted from late Wednesday afternoon into early Friday morning.

Temperatures will start the day mild on Wednesday, but drop below freezing by evening. The high on Thursday will be near 0C (32F) in Montreal. Much colder weather will return for Friday and the upcoming weekend, with temperatures dropping back below normal.

Thursday, February 20, 2020

A well deserved period of calm weather for Montreal

The carnage left behind after blowing snow resulted in a 140 vehicle pile-up on Highway 15 in South Shore La Prairie. Sadly 2 fatalities occurred along with over 30 injuries, some critical. (CTV News)
High pressure is cresting over southern Quebec early Thursday morning, along with clear skies and cold temperatures. The high for Montreal will be around -10C (14F) Thursday, dropping to -19C (-2F) overnight into Friday morning. On Friday, warmer air will begin to stream into the region, with a few clouds around and daytime highs of -2C (28F). This weekend into early next week will feature calm weather, with lots of cloud cover, but very mild temperatures as we go above freezing each day from Saturday through Tuesday. Look for highs in the plus 2C to 5C range (35 to 41F) and lows just below freezing, between -1C and -4C (25 to 30F). The next change for precipitation will arrive by late Tuesday in the form a light rain or snow.

The forecast comes as a relief to many after what has been a conveyor belt of storms this month. Since February 1st, Montreal has recorded 60.4cm of snow, over 2 feet. Other regions in southern Quebec have had even more, as much as 70cm on Ile Perrot for example. Our most recent snowfall came along a strong arctic cold front early Wednesday morning. The front produced scattered snow squalls, some which were quite potent in southern Quebec, dropping 2-5cm of snow in a very short period of time during the Wednesday morning commute. The front was followed by rapid clearing but also very strong winds and dropping temperatures. Wind gusts were reported between 60-70km/h in southern Quebec on Wednesday through the middle portion of the day.

Massive multi-vehicle accident
The wind, combined with all the fresh snow on the ground, produced very dangerous blowing snow conditions across area highways, especially south of Montreal. During the early afternoon on Wednesday, a small accident during a white-out on Highway 15 in La Prairie, became a massive 140 vehicle pile-up within minutes. The accident resulted in 2 fatalities and over 30 injuries, some critical. The Surete du Quebec continue their investigation, but indicate that poor visibility and speed were the likely culprits.

The highway was reopened at 1:15am Thursday morning after a lengthy cleanup.  This stretch of road is notorious for major accidents from blowing snow. The winds blow the snow onto the highway from the frozen La Prairie basin along the St. Lawrence Seaway. Wednesdays weather shows you just how dangerous and changeable winter driving can be, even on what appears to have been a sunny February afternoon. We simply drive too fast for the conditions.

Monday, February 17, 2020

Snow expected for the Tuesday morning commute in Montreal

Another round of accumulating snow is forecast for the Tuesday morning commute in Montreal. Allow extra time on Tuesday morning, with 5 to 10cm expected for the city.
Snowfall Warning in effect for the Laurentians, Lachute, St Jerome and Quebec City
Winter Weather Advisory for the Ottawa and St. Lawrence Valley

The temperature roller coaster ride will persist this week, as it has all winter long. High pressure has been in control of our weather Monday, with abundant sunshine and seasonable temperatures. Clear skies will prevail into the evening hours, with temperatures dropping quickly after sunset to early lows of -13C (9F) in Montreal.

Clouds will be on the increase after midnight as developing low pressure moves from the southern plains into the Great Lakes. A warm front will lift north with the storm system, producing and area of light to moderate snowfall. The snow will move into Ontario overnight and unfortunately approach Montreal in time for the morning commute. Accumulations of 5 to 10cm are likely along the St. Lawrence River, with 15-20cm north of Laval into the lower Laurentians. These regions are under snowfall warnings. A weather advisory is in effect for the St. Lawrence Valley in Ontario.

The timing of the snow will result in another slow morning commute in southern Quebec. Look for snow covered roads and reduced visibility. Precipitation should taper off in the the afternoon, as temperatures rise to the freezing point. Winds are expected to pick up as well on Tuesday afternoon, gusting between 40 and 60km/h in Montreal.

The temperature will briefly rise above freezing up to 3C (38F) during the evening hours, as the warm front lifts north of the valley. A few isolated showers are possible, changing back to flurries as the  temperatures drops once again below freezing, down to -5C (23F) by Wednesday morning.

Wednesday, February 12, 2020

More snow followed by arctic air for Montreal

The mounds of snow are growing across the suburbs of Montreal. Crews have been hard at work carting away the snow from three separate storms over the last week. More is on the way Thursday, with 5 to 10cm expected over southern Quebec. (ValleyWeather Photo)
Another shot of snow is on the way for southern Quebec, adding to the 45 to 55cm that has fallen since last Thursday. Low pressure over the Ohio Valley will rapidly move across central New England on Thursday and out into the Atlantic. The storm will be quickly followed by a surge of arctic air late in the day.

Snow will spread into Montreal before the morning commute Thursday, and taper off to flurries in the afternoon. Environment Canada is aiming low for Montreal, calling for 2-4cm total accumulation. I feel it will be more in the order of 5 to 10cm in southern Quebec and eastern Ontario, with up to 15cm along the US border. The snow may be enhanced briefly during the morning hours as an arctic cold front cuts across the region. Winds will increase out of the northwest and temperatures will plummet in the afternoon and evening hours. The high Thursday will be reached early in the morning in Montreal, at -1C (30F). The temperatures will fall into the -20s by Friday morning across our region. Most of central Quebec is under extreme cold warnings, for windchill readings near -40C. Montreal can expect windchill values well into the -20s.

Friday will be blustery and cold, with daytime highs struggling to reach -12C (10F). The weekend will be milder once again, but unsettled with plenty of clouds and flurries around. As we head into next week, another winter storm may impact Montreal by Tuesday with measurable snow.

Saturday, February 08, 2020

Schools closed - hundreds of accidents from largest winter storm of the season

A major multi-vehicle accident forced the closure of Highway 73 south of Levis, Quebec. (Photo by Jean-Philippe Veilleux via Facebook)
Students were given a rare snow day in Montreal and across most of southern Quebec on Friday, as the biggest snowstorm of the season hit the region. Strong low pressure raced from northern Virginia across interior southern New England and into New Brunswick by days end. The system spread heavy snow across the St. Lawrence Valley, with a storm total of 35cm in Montreal. Elsewhere in the province up to 50cm of snow fell. In Ontario, 25-35cm fell from Ottawa south into the Seaway. A record low barometric pressure for February of 970.2mb, was recorded in the center of the storm over Connecticut. Montreal's lowest pressure was an impressive 979.8mb at 2pm on Friday. The storm could have been even worse, but moved rather quickly across our region.

Conditions were less than ideal within the city limits as well, with rapidly accumulating snow making driving and parking difficult. (ValleyWeather Photo)
Strong winds occurred with the snow, gusting to 61km/h in Montreal and as high as 95km/h in the Quebec City area. The winds produced widespread blowing snow, enough to create white-out conditions, closing several highways in and around Quebec City. Visibility was under 1km for most of the day in Montreal. Provincial Police reported over 1200 separate accidents across the province as a result of the storm, including two multi-vehicle collisions. One occurred on Highway 20 at the Ontario border, forcing the closure of the road and long delays. The other was near Levis involving as many as 35 vehicles. Another major accident occurred on Highway 40 in Vaudreuil during the afternoon commute.

Keeping the streets clear during the storm in Sainte-Anne-de-Bellevue. 
(Photo - Ville de Sainte Anne de Bellevue)
Air travel was hit hard by the storm, with hundreds of delays and cancellations reported at Trudeau Airport. The airport in Burlington, Vermont closed Friday for the first time in 20 years. Inter-city buses as well as those within metro Montreal faced long delays.

The storm was far reaching, spreading heavy snow from Texas to Newfoundland. On the warm side of the system, severe weather, tornadoes and flooding stretched from Louisiana to Pennsylvania.

Friday, February 07, 2020

Major snowstorm today for Montreal and southern Quebec

Heavy snow across eastern Ontario and southern Quebec will make travel very difficult today. Since early Thursday, 14cm has fallen at Trudeau Airport, with another 20-30cm possible today. (ValleyWeather Photo)
Winter Storm Warning in effect for metro Montreal.

Light snow is falling early Friday morning across the region. The snow has been mixed at times with freezing drizzle overnight, but that will end soon, if it has not already. Radar is showing very heavy snow to our south and west, with rates of 1-2cm per hour expected for Montreal this morning into early afternoon. As of 5am Friday, Montreal had already received 14cm of fresh snow.

Rapidly strengthening low pressure will move from Virginia across southern New England today and into Atlantic Canada tonight. A swath of heavy snow is expected to develop over the St. Lawrence Valley early Friday morning, and persist into the late afternoon. Near blizzard conditions are possible across southern Quebec as increasing northeast winds up to 60km/h develop today. The combination of heavy snow and blowing snow will make travel difficult today across all our regions. For that reason, most major school boards in metro Montreal and across southern Quebec, have cancelled classes for the day. Some flight cancellations have been reported at Trudeau Airport, so check you flight status before heading out to the airport.

A major snowstorm will impact the St. Lawrence Valley today as well as southern Quebec, New England, and Atlantic Canada. (AccuWeather.com)
The snow will taper off to flurries after midnight tonight, with total storm accumulations of 30 to 50cm expected. The high temperature of -5C has been reached already, with temperatures steady or falling today to an overnight low of -15C, with windchill readings in the -20s.

Wednesday, February 05, 2020

Extended winter storm for southern Quebec

Deepening low pressure is forecast to move across New England late Thursday and Friday, with 15 to 25cm of snow possible across southern Quebec. (AccuWeather.com)
Special Weather Statement in effect for Montreal.
Winter Storm Watch posted for Sherbrooke and the Townships.
Winter Storm Warning in effect for northern New York and Vermont.

Much colder air settled across the St. Lawrence Valley on Thursday after several days of above normal temperatures. The high on Thursday was -2C here on L'Ile Perrot, reached at midnight. The mercury has been falling all day to our current temperature of -9.6C. Temperatures should level off  by midnight as clouds thicken up in advance of our next winter storm.

Overnight an elongated warm front will lift northward towards southern Ontario and Quebec. Precipitation should begin overspreading the region by daybreak from the US border into Montreal. Snow will be steady during the morning hours with 5 to 10cm expected by late afternoon in Montreal. The snow will likely impact both the morning and evening commute in the region. Spotty freezing rain may mix in along the US border, but it should be light.

Strengthening low pressure will move from the southern US into New England on Friday with additional snowfall expected. Montreal will get a brief break in precipitation Thursday evening, before more snow, heavy at times arrives overnight into Friday morning. The second batch of snow will be intense at times, with an additional 10-15cm possible for Montreal. Storm totals may exceed 30cm over the Eastern Townships, and 40cm over northern New York and Vermont. Lesser amounts of 10-20cm are expected across eastern Ontario.

As the low pressure deepens and moves northeast into Atlantic Canada, wind speeds will increase across southern Quebec, up to 50km/h at times. Gusty winds will persist into Friday, with areas of blowing snow possible. Temperatures throughout this storm will remain below freezing in Montreal. The special weather statement currently in effect for Montreal may be upgraded to a weather warning by Thursday morning.

Thursday, January 30, 2020

A quiet end to a warm January in Montreal

The Niagara region during the epic Blizzard of 1977. This week marks the 43rd anniversary of that storm, back when winter had bite. In stark contrast, Montreal is about to finish one of the warmest Januaries on record.
High pressure is cresting over southern Quebec on Thursday, with clear and seasonable weather expected for Montreal. January 2020 is just about done, and it was a warm one to say the least. The average temperature through January 29, was -5.5C (22.1F), well above the normal of -9.7C (14.5F). We have recorded 13 days above the freezing point, remarkable for Montreal in January, and nearly double the long-term average. Officially at Trudeau Airport, there were no overnight lows below -20C (-4F). The long-term average from 1981-2010 is 7.6 days.

Our weekend storm is no more. The low in question will travel well offshore, sparing southern Quebec. A decent storm is likely in Atlantic Canada and Newfoundland. A western system may bring a dusting of snow to Ontario and Quebec on Sunday. (AccuWeather.com)
As far as precipitation is concerned, snowfall was relatively normal, with 50 to 60cm falling across metro Montreal, the normal is 49.5cm. The snow was scattered in nature, with no real large snowstorms. Rainfall was well above the normal of 27.3mm, with 50.0mm falling. The record-breaking rainstorm of January 11 was responsible for 44mm of that total. The mild weather has stretched across most of eastern Canada and the US. The Great Lakes are nearly ice-free, with only 6.6% of the surface frozen. Lake Erie and Ontario are virtually ice-free, with less than 2% coverage. The St. Lawrence River has very little ice as well, and what there is, is thin and dangerous.

Looking ahead to February, more of the same can be expected to start the month at least. Temperatures will be above normal, with just a slight chance for some flurries Saturday and late Sunday. No major storms are on the horizon at this time. The coastal low we were anticipating may affect Montreal earlier in the week, will remain offshore, impacting Atlantic Canada.

As the sun begins to strengthen in February and the days get longer, winter begins the epic battle to hold off spring. There is still plenty of winter to go, with February and March historically producing our biggest storms in Montreal. There are indications that the February will eventually turn colder, but that was the same scenario we were looking at for January, and it never materialized. Let's see what the groundhog has to say this Sunday, he may have better luck than me!

Friday, January 24, 2020

Complicated weekend storm for Montreal and Ottawa

Another weekend, another messy winter storm for southern Quebec. A special weather statement is in effect for Montreal, for a mix of rain, wet snow and freezing rain through Sunday.
This has not been an easy winter to predict for both professional and amateur meteorologists alike. For instance, I was convinced that once January turned colder, that frigid air was with us well into February. Now here we sit Friday afternoon with the temperature at 1C (34F), the third consecutive day above freezing. It seems that cold air this winter has been fleeting at best, the bulk of the arctic air trapped across northern Canada, with just an intrusion or two into the western provinces.

For this reason, the storm systems have been extremely challenging to forecast, especially the precipitation type. This weekends winter storm is no different. Right up to this mornings computer model runs, the various forecast scenarios have been all over the place, this with less than 24 hours to go before the storms arrival. So here goes my best effort at breaking down the weekend weather.

Precipitation should change to snow late Saturday, with 10cm expected in metro Montreal by Sunday morning. (AccuWeather.com)
A complex area of low pressure will move across the central Great Lakes and just south of Montreal on Sunday, while a second low develops off the southern New England coast. Clouds will increase early Saturday morning, followed by some scattered light rain or freezing rain into the early evening hours. Temperatures will be marginal at best for frozen precipitation in Montreal, with the mercury close to 2C (36F). Overnight Saturday into Sunday, slightly colder air should be pulled into the region, with precipitation becoming predominately snow for Montreal and points north and west including Ottawa. Precipitation may remain liquid south of Montreal. On Sunday, look for a mix or wet snow and perhaps some rain. If the precipitation remains as snow, most areas will receive between 10 and 20cm. Any region that mixes in with rain or freezing rain, will see less accumulation.

The temperatures will remain either side of 0C (32F), from late Saturday into Sunday. By no means is this forecast set in stone. I expect we will see fluctuations in the type and quantity of precipitation forecast. A change in the temperature of a degree or two either way, or any alteration in the storms track, will result in very different weather here in the St. Lawrence Valley. Skies will clear out on Monday, with temperatures remaining above normal.

Monday, January 20, 2020

Historic Newfoundland blizzard was meteorologically epic

A typical scene in St. John's, Newfoundland after a fierce coastal storm dumped 76.2cm of snow in 24 hours on the city. (CBC)
By now most of you are aware of the monster storm that hammered eastern Newfoundland on Friday and Saturday. The powerful ocean storm drew off the warm waters of the Gulf Stream, while Arctic air fuelled the system from the northwest. The storm had humble beginnings, bringing 5 to 10cm of snow to parts of Ontario and Quebec last Wednesday, before moving off the Maine coast on Thursday. It then blossomed into a major Atlantic winter storm, a white hurricane if you will, deepening to a remarkable 954mb low. That barometric pressure is comparable to a category 3 hurricane.

Above: Transportation and Works Newfoundland plows having a difficult time on Pitts Memorial Drive, Saturday, January 18. The four lane highway was covered in snowdrifts reaching over 15 feet high (Transportation and Works Newfoundland Photo)
Many of you have likely viewed the photos on news and social media of the mountains of snow in St John's, up to the rooftops in many cases. The amount of snow was incredible, 76.2cm in 24 hours in St. John's. That smashed the cities record of 68.4cm set on April 5, 1999. Even more fell in other parts of the Avalon Peninsula, including 93cm at Mount Pearl. That was just one part of this ferocious storm, the other was the relentless wind. We may never know just how strong it was in St. John's, because the anemometer failed at the airport. Before it did however, winds gusted up to 134km/h (83mph). Forecasters estimate the wind may have exceeded 150km/h in St. John's. The wind was remarkable across the Avalon, reaching 171km/h (106mph) at Green Island and Fortune Bay. In St John's, wind gusts exceeded 100km/h for 15 consecutive hours.

A spectacular NOAA satellite image of the storm exploding off the Newfoundland coast on Friday, January 17, 2020.
The storm also produced wave heights along the Atlantic coast of over 15 feet. The combination of wind and snow produced blizzard conditions for almost 21 hours. Visibility at best was few metres and near zero most of the time. A state of emergency was declared across the Avalon, and remains in effect for many locations including St. John's on Monday. Roads, the airport, businesses and schools remain closed. The Telegram Newspaper in St. John's has halted printing and distribution until the state of emergency is lifted.

Firefighters battle near-zero visibility in St. John's on Friday, January 17, 2020
Close to 300 Canadian Armed Forces personal are on the ground Monday, helping weary first responders and public works employees deal with the aftermath of the storm. In some cases, 15 foot (4.5 metre) drifts are blocking roadways, delaying in the efforts to restore power. Thousands of customers were in the dark as a result of the storm.

More snow fell late Sunday, before the temperature nudged above the freezing mark. Windy and colder weather is forecast this week, but thankfully a break in the parade of storms the region has had this winter. To date, St. John's has recorded an amazing 248cm of snow this winter. By comparison, Montreal has received 110cm.

Friday, January 17, 2020

Snowy weekend for Montreal

The Thursday morning commute in Montreal was a slow one, with 5cm of snow falling in the city. Closer to 10cm occurred south of Montreal. Numerous accidents were reported by provincial police, especially off-island to the south and west. (Valley Weather Photo)
After a rather mild December and early January, winter weather has started to spread across the country in earnest. Early Friday morning, temperatures are around -20C (-4F) across southern Quebec, along with a gusty northwest wind. Windchill values are as cold as -30C. The cold air poured into the region behind low pressure, that produced 5 to 10cm of fluffy snow across southern Quebec on Thursday.

High pressure will dominate the day in Montreal, with abundant sunshine, but cold temperatures, the high will be -14C (7F). Friday night will be mostly clear and cold once again, with overnight lows of -20C. On Saturday, clouds will increase rapidly as strengthening low pressure travels down the St. Lawrence Valley. Expect snow to spread across eastern Ontario and southern Quebec during the afternoon and evening hours. The snow could be heavy at times overnight into Sunday morning. At this time, amounts will remain below warning levels for Montreal, but could approach them in Ottawa. A general 10 to 15cm is possible across southern Quebec, with as much as 25cm in eastern Ontario. Winds will be rather gusty throughout the storm, up to 50km/h. Expect areas of blowing and drifting snow. Travel will be impacted across the region. The snow should taper to flurries on Sunday. Temperatures will remain cold throughout the period and into next week.

The cold is just a small sample of what western Canada has been experiencing over the last week. Overnight lows have been in the -30s and -40s across Alberta and Saskatchewan, with windchill values as cold as the -50s. The cold has even seeped in coastal regions of British Columbia, where Vancouver has received more snow in January, 34.5cm, than Montreal 23.6cm.

It appears the colder weather is with us for a little while now, certainly to close out January and even into the early portions of February. This is in stark contrast to the above normal temperatures that have dominated Montreal weather since the start of December.

Sunday, January 12, 2020

58,000 without power in Quebec from wind and ice

While we were prepared for the worst, I was pleased to see mostly sleet (ice pellets) had fallen on Ile Perrot overnight, with very little ice accretion. Freezing rain is falling this morning, mixed with snow and ice pellets. Precipitation should taper of this afternoon. (ValleyWeather)
Over 58,000 Quebec homes and businesses are without power this morning after a night of freezing rain and strong winds. Most of the outages are in the Monteregie south of Montreal. The island of Montreal is in decent shape so far. We caught a huge break on Saturday, as mild air held on a few hours longer producing more liquid rather than frozen precipitation. Since the changeover around 10pm Saturday evening, most of the freezing rain has been mixed with ice pellets,which does not stick to trees or power lines. The wind has been gusting to 60km/h at times from the northeast.

Hydro Quebec has more than 100 teams on the road Sunday morning to restore power as quickly as possible. Power outages have also been reported in central and eastern Ontario. The precipitation is expected to continue through the middle portion of the day in Montreal, with another 10 to 15mm of freezing rain possible, especially south of the city. Some sleet and light snow will mix in as well. Conditions should start to improve later this afternoon. Winds will diminish as well by this evening. The temperature will remain nearly steady near -5C (23F) today in Montreal, dropping to -11 (12F) by Monday morning. 

The massive winter storm creating the heavy rain and ice in Quebec, stretched from Texas to Atlantic Canada. The system not only produced flooding rains in Ontario and Quebec, but heavy snow to the north and west of the track and deadly tornadoes to the south. Along the US east coast on Saturday, a surge of warm air generated by the same storm, resulted in over 60 record highs, some dating back to the 1890's.

The heavy rain Saturday produced plenty of localized flooding across the region. Montreal received a record breaking 44.2mm at Trudeau Airport, crushing the previous daily record of 18.6mm set in 2008. All that rainfall is now ice, with a current temperature of -6C (21F) in Montreal, down from Saturday's high of 7C (45F). If you head today be extremely careful as all surfaces are covered in snow and ice.

Saturday, January 11, 2020

Major freezing rain event for southern Quebec and eastern Ontario

The heaviest freezing rain will occur Saturday night in a narrow band across central Ontario and extreme southern Quebec. Within this zone up to 25mm (1 inch) of ice is possible. (AccuWeather.com) 
Freezing Rain Warning in effect for southern Quebec and eastern Ontario.
Ice Storm Warning for the St. Lawrence Valley, northern New York and Vermont

Travel not recommended tonight in southern Quebec and Ontario. Plan for power outages.

A frontal boundary lies just north of Montreal early Saturday morning, the dividing line between very warm air to our south and arctic air to the north. Strong low pressure will ride along the front over the next 12 to 24 hours, spreading heavy rain and eventually freezing rain across the region.

Radar early Saturday morning is showing heavier rainfall moving into southwestern Quebec. Rainfall will continue all day, with as much as 25mm in Montreal. The rain will lead to isolated flooding and ponding of water on roadways. Temperatures today will be very mild, reaching up to 10C (50F).

The frontal boundary will begin to shift south early this evening across southern Quebec, ushering in much colder air at the surface, while the warm air remains aloft. This will set the stage for several hours of heavy freezing rain. Exactly where the boundary sets up, will establish who receives the most ice accretion. At this time is appears the heaviest frozen precipitation will occur across the southern portions of metro Montreal south to the US border, and along the St. Lawrence Valley towards Brockville and Kingston. Some locations within this band will receive up to 30mm of freezing rain. This is more than enough to take down tree branches and power lines.

Regions further north of this zone, including Laval, will cool off very quickly and switch over to ice pellets (sleet) or snow. The temperature will fall quickly down to -7C (19F) overnight in Montreal, and remain fairly steady Sunday. Winds will pick up as well overnight and Sunday, gusting as high as 70km/h in southern Quebec. The wind could take down ice covered branches and power lines on Sunday.

The weather will improve late Sunday and Monday, with just a few flurries forecast along with seasonable highs of -6C. Much colder air arrives late next week, remaining for the balance of January.

Friday, January 10, 2020

Dangerous freezing rain event for Montreal and Ottawa

A narrow band of heavy freezing rain will set up along a frontal boundary Saturday into Sunday. Montreal has the potential to receive a significant amount of frozen precipitation. (AccuWeather.com)
Special Weather Statement: Montreal and Ottawa.
Winter Storm Watch: St. Lawrence Valley

A period of heavy freezing rain is forecast for the St. Lawrence Valley including Montreal late Saturday into Sunday.

A very dangerous weather situation is setting up for the upcoming weekend across a portion of Ontario and southern Quebec. A warm front is lifting north of Montreal Friday morning, with temperatures expected to rise rapidly today up to 5C (41F). A few flurries or spotty showers are expected today. Heavy rain changing to freezing rain is likely Saturday.

Ice Storm
On Saturday the aforementioned front will begin to settle south once again, with arctic air located just to the north and a surge of record breaking tropical air to the south or Montreal. Along the front, low pressure will lift north, accompanied by abundant moisture. Heavy rain will develop across the region, with as much as 25mm (1 inch) expected. Saturday evening, cold air is expected to bleed back into the St. Lawrence and Ottawa Valley as well as extreme northern Vermont and New York, with rain changing to freezing rain. Ice accumulations may be significant, with more than 25mm possible by Sunday morning. This amount of ice accretion will result in tree and power line damage. Expect power outages. Strong winds are also expected on Sunday, up to 70km/h in Montreal, which will only add to the damage potential. The precipitation will taper off Sunday afternoon.

The temperatures will be wild this weekend, possibly reaching a record high 10C (50F) in Montreal on Saturday. The previous record was 9.4C (49F) set in 1975. However the mercury will fall just a quickly Saturday night once the cold front slips south of Montreal, down to -7C (19F). The temperature range will be very dramatic across a very small region Saturday evening. Travel will become extremely difficult

Now is the time to plan for power outages. Charge your devices, prepare your home and make sure you have a full tank of gas. There is still some uncertainty in the path of the storm and where the freezing rain will set up. Hopefully Montreal ends up with more liquid precipitation or sleet, but at the moment, it is looking like freezing rain.

I will update the forecast and any warnings throughout the event.

Wednesday, January 08, 2020

Significant winter storm possible for Montreal this weekend

Significant amounts of rain, freezing rain and snow are possible this weekend in Ontario and Quebec.
Expect a temperature roller coaster ride over the next few days, with a significant winter storm likely by the weekend for parts of southern Ontario and Quebec.

A cold front has crossed southern Quebec early Wednesday morning, setting the stage for a frosty 24 hours. Gusty winds up to 50km/h will accompany dropping temperatures into Thursday morning, with lows round -15C (5F) expected in Montreal. Thursday will see increasing clouds as a very complex winter storm begins to take shape across the central portion of the US.

Montreal will see increasing temperatures on Thursday as a warm front lifts across the St. Lawrence Valley. The low will be reached early in the evening, with the mercury climbing through Friday morning, all the way up to 7C (45F). Arctic high pressure will retreat just to our north, setting up a very tight temperature gradient across southern Quebec and Ontario. This will set the stage for a wide variety of precipitation this weekend.

A cold front will lie very close to Montreal early Saturday morning, with strong low pressure expected to ride along the front late in the day. This system will have abundant Gulf of Mexico moisture accompanying it, with as much as 75mm (3 inches) of precipitation possible in some locations across southern Ontario and Quebec. The forecast difficulty lies in the exact temperature when the influx of moisture arrives.

At this time rain is forecast on Saturday in Montreal, changing to freezing rain or snow late in the day. Temperatures will drop rapidly once the front settles south of the city. Gusty winds are also forecast with this storm. Some locations in the Montreal region may receive significant amounts of freezing rain or snow.

As the exact placement of the front becomes more clear, weather watches and warnings will likely be issued. If you have any travel plans this weekend, pay close attention to the latest forecasts.