Spring snowstorm on the way for southern Quebec

You may want to wait just a few more days before removing your winter tires. Montreal has enjoyed a very easy end to winter so far, with only 2.2cm of snow measured at Trudeau Airport during the month of March. That is about to change as a potent cold front and developing east coast storm are forecast to bring steady wet snow to southern Quebec on Thursday.

Despite sunshine and temperatures in the middle teens Tuesday afternoon in Montreal, we are looking at a spring snowstorm starting late Wednesday and persisting into Thursday. Before then, we can expect fair skies and mild temperatures through Wednesday afternoon. A potent cold front is forecast to approach from the west Wednesday afternoon, passing across southern Quebec in the early evening. Rain is forecast to develop across southwestern Quebec along with dropping temperatures throughout the evening. 

A special weather statement has been issued for southern Quebec including Montreal for up to 10cm of snow on Thursday. In northern New York and Vermont, a winter storm watch is now in effect, with 10-25cm possible. (AccuWeather.com Image)

High temperatures on Wednesday will reach a mild 14C (56F) by midday before the arrival of precipitation. Afterwards expect a steady fall to the freezing point by midnight, with rain changing to snow. The front will become stalled across eastern New England, as low pressure develops over Delaware and moves northeast towards Maine. Steady wet snow is expected in the St. Lawrence Valley through the day Thursday, with early estimates of 10-15cm for the region. Across portions of the Townships and Adirondacks of New York, 15-25cm is possible. Travel will be difficult on Thursday. 

The snow will taper off to flurries late Thursday in Montreal, with partly cloudy skies and cold temperatures expected during the overnight period and Friday. Lows will be down to -10C (14F) by Friday morning. The snowy, cold weather will be short-lived, as sunshine and mild temperatures return for the weekend.

The strong cold front expected to sweep Ontario and Quebec is part of the same storm system that hammered parts of southern Alberta and Saskatchewan on Monday with hurricane force winds and heavy snow. A peak wind gust of 159km/h (98 mph) was observed on Nakiska Ridgetop just west of the Kananaskis Village in Alberta. In Saskatchewan, winds reached 120km/h (75 mph) at Swift Current. Parts of the Trans Canada Highway were closed for hours as the wind and heavy snow made for near-zero visibility. The sudden cold was in stark contrast to the record highs that occurred just a few hours earlier on Sunday afternoon.

Unsettled weather week ahead for southern Quebec

Strong west winds of 50 to 80km/h are forecast for Montreal Sunday night into Monday, along with rain changing to snow showers after midnight.

March and April can be volatile months as the seasons battle it out. We have already witnessed very active and highly variable weather in southern Quebec over the last week, and this trend will continue. Strong low pressure is lifting northwest of Montreal Sunday afternoon, accompanied by another round of heavy rain and strong winds. After the 20 to 30mm of rain that fell on the city Friday, we can expect another 10 to 20mm through Sunday evening.

Another round of steady rain is expected Sunday afternoon into the evening hours along with very strong winds. The rain may end as a period of light snow after midnight in Montreal.

The big weather story for the St. Lawrence Valley with the current storm, will be the strong winds that develop late this evening. A cold front will sweep across southern Quebec by midnight, ushering in the strong winds along with much colder temperatures. Winds will increase out of the west and northwest, between 50 and 80km/h. The gusty winds will persist into Monday, along with any leftover rain, changing to snow. The temperature will fall from 10C (50F) Sunday afternoon down to -2C (28F) by Monday morning.

Monday will be very windy and cold, with flurries and high temperatures struggling to reach plus 3 or 4C (37 to 40F). The cold air will be short-lived as temperatures are forecast to rebound by Tuesday, with highs up to 13C (55F) under fair skies.

Spring Snow

As we look ahead, another very strong cold front is forecast to cross the region late Wednesday evening. Low pressure is also expected to develop in southeast New England. The combination of deep Atlantic moisture and colder temperatures may bring us a period of rain changing to snow Wednesday night. There is a possibility of accumulating snow into Thursday morning for parts of southern Quebec and eastern Ontario. The evolution of this system will have to be closely monitored.

A very rare March tornado damaged this home in Middlebury, Vermont on Friday afternoon. The EF-1 rated tornado cut a swath of damage a mile long. On average the state only reports one tornado each year usually during the summer months. An EF-1 tornado is capable of winds up to 177 km/h. (WPTZ Photo)

Severe Weather & Tornadoes

We are not the only region with stormy weather. On Friday, severe thunderstorms across Vermont produced a very rare March tornado. The EF1 rated storm cut a swath of damage 1 mile long near Middlebury in the west-central portion of the state, approximately 200km south of Montreal. Several homes were damaged with at least two injuries reported.

Meanwhile the southern US has been experiencing severe weather, with dozens of tornadoes and flash flooding. Tornadoes on Thursday and Friday were responsible for several fatalities in Alabama. While strong thunderstorms put down over 125mm (5 inches) of rain in Nashville on Saturday. The heavy rain produced widespread flash flooding with at least 4 fatalities reported. Hundreds needed to be rescued from their vehicles and homes as a result of the flooding in Nashville and across Tennessee.

Overnight thunderstorms rattle the Montreal region

The first thunderstorms of the season rumbled across southern Quebec overnight, waking up many in the Montreal region. More isolated storms are possible tonight and Friday, especially south of Montreal. 

Heavy rain warning for Montreal

As written Wednesday afternoon on this very blog, we had some bone-rattling thunderstorms overnight. One particular lightning strike at 3:25am seemed to wake up the entire West Island as well as off-island communities. Social media lit up immediately with theories as to what the loud sound was. It certainly rattled the windows on Ile Perrot, shook the entire house and set off car alarms, but it was not an earthquake or aliens. It was simply a rare March nocturnal thunderstorm.

A warm front lifting across southern Quebec was the culprit. The cold dense air at the surface was being overridden by very warm air higher in the atmosphere. The thunderstorms were not that intense in nature, with very little wind and only 5mm of rainfall on Ile Perrot. What the storms did have was some pretty intense lightning and thunder. The thunder was capped by the warm air aloft and reverberated back to the surface making the rumble seem much louder and longer than usual. With the cold air at the surface and warm air above it, the warm air will act like a ceiling, or insulator to things like sound waves. The sound from the thunder will hit the bottom of the warm layer and bounce back to the ground. This was not your typical warm, humid summer afternoon storm. So if anybody asks you what that was, you definitely have the answer.

We will have a very warm and windy day in Montreal, with winds increasing to 50km/h out of the southwest. We can expect a record high of 21C (70F). A strong spring storm arrives on Friday, with heavy rain and gusty winds. Rainfall warnings are in effect for Montreal and southern Quebec, with up to 40mm possible. North of Montreal freezing rain and even wet snow is forecast. Temperatures will cool off considerably from Thursday, with highs struggling to reach 10C (50F) in Montreal, and dropping to the freezing point into Saturday. The weekend will be even colder, with flurries possible.

You have to love March in Montreal, never boring.

Weather whiplash - from record spring warmth to snow

A warm front may produce some scattered thunderstorms across southern Ontario and Quebec late Thursday and early Friday morning. Record warm air will then surge into Montreal on Thursday.

Montreal managed to sneak in a record high on Tuesday afternoon, reaching 19C (66F), surpassing the previous mark of 18.6C (65F) set in 1979. It was our second record high this month, with a third likely on Thursday in Montreal as temperatures are expected in the upper teens and even low 20s. The record to beat for March 25 is 16.7C (61F) set in 1996. Before then, a warm front will lift across southwestern Quebec Wednesday evening and overnight. We can expect some much need showers and even a few scattered thunderstorms. Thursday will be partly sunny, breezy and very warm, with gusty southwest winds pulling in the warmth from the deep southern US. Enjoy Thursday, as the weather will turn stormy into Friday. 

The first of two strong low pressure systems will move across southern Ontario and Quebec on Friday, accompanied by much cooler temperatures, strong winds and heavy rainfall. There may even be some wet snow in some locations. The second storm on Sunday may bring more snow to the region.

SPRING SNOW

I really thought we would end the month quietly, but it appears it may go out like a lion. We have a pair of storms forecast to impact southwestern Quebec starting Friday, along with much colder temperatures. The first system will deliver a steady rain and strong winds Friday, with as much as 35mm of rainfall. The high will drop down to 9C (48F), with overnight lows Saturday morning near the freezing point. Even with the heavy rainfall, I am not expecting any flooding at this time as it has been a very dry month to date. Only 9.8mm of precipitation has fallen at Trudeau Airport. The rain will taper off to a few showers or perhaps even some flurries by Saturday morning. We will have a brief break Saturday afternoon before the second system arrives.

A second potent storm will move across the Great Lakes and close to Montreal late Sunday into Monday. Computer models have been having a difficult time with the exact track of this storm. The European model is even hinting at a decent snowstorm for parts of our region. At this time, I am leaning towards a warmer solution, with mostly rain for the city. We are expecting another 15-20mm of rain, however that may change depending on the actual storm track.

We can expect some wet snow as well at the onset of the precipitation. Parts of southern Quebec, especially north of Montreal, may see a significant wet snow event. Temperatures will be much colder Sunday, with a high of 4C (39F) expected. Overnight lows will likely drop to near the freezing point.

Conditions should begin to improve late Monday, with temperatures closer to normal.

It looks like a tranquil end to winter in Montreal

A massive winter storm dumped nearly 70cm (27 inches) of snow on Denver, Colorado last weekend. It was the fourth largest storm in that cities history. The snow closed the airport and numerous highways across the state and into neighbouring Wyoming and Nebraska. The storm was expected to being some snow to our region, but will now pass well south of Quebec on Friday. (Colorado State Patrol)

Astronomical spring officially arrives at 5:37AM Saturday morning, along with very mild weather. March has been a tame month all around, and it appears it will remain that way right to the end. I am not saying it is not possible to get a sneaky snowfall or two between now the end of April, it usually happens, but for now no major storms are on the horizon. Dare I say winter may be over! March to date has been extremely dry, with only 7.4mm of rain and 2.2cm of snow. The long-term average is 29.7mm of rain and 36.2cm of snow for the entire month.

Skies are clearing Thursday afternoon, as high pressure moves into southern Quebec. It is expected to remain in place through at least next Wednesday. A strong late winter storm, responsible for several feet of snow in the US Rockies last weekend, is sliding well south of Quebec today and Friday. As mentioned the storm produced record snowfall, and at least two dozen tornadoes Wednesday across portions of the central and southern US. The low will move off the east coast Friday, brushing parts of eastern Nova Scotia and Newfoundland, with snow and blowing snow.

As high pressure arrives in Montreal, we can expect breezy conditions and cold temperatures on Friday. Lows will be around -13C (9F) in the city, with daytime highs around -1C (30F). Gusty northwest winds up to 40km/h will make it feel even colder. The cold weather will be short-lived. Temperatures will warm quickly on Saturday, with a high of 8C (48F). Looking ahead, Sunday through next Tuesday will be mainly sunny and very mild in Montreal, with highs into the double digits reaching 15C (59F). 

SPRING FLOODING?

With very light precipitation this month as mentioned, and the relatively slow thaw we have been experiencing, water levels around southern Quebec are stable at the moment. There is no immediate threat of flooding. However that could change as river ice melts or if we have significant precipitation. So for the time being have your flood plan ready, and remain vigilant. The Quebec Government has an excellent resource page HERE. It is also advised at this time that you remain off any ice, as the spring thaw is well underway across southern Quebec.

A return to colder weather for Montreal

With spring a little over a week away, area waterways are becoming increasingly dangerous. The warm weather this week has allowed the ice to slowly begin the break-up process and become unstable in places. The water is icy cold and  flowing fast. Be vigilant along the shore and stay off the ice.

Our preview to spring is just about over in eastern Canada. The high in Montreal on Wednesday was 9C (49F), just shy of the record high for the date. We have a much better chance of reaching the record today, 11.2C (52F) set back in 2012. The forecast is for a high of 10C (50F), however there is a good chance we will surpass that. As I write, St Anicet, 70 kilometres southwest of Montreal is already at 14C (58F), while Ile Perrot is 7C (45F), so the warm air is close by. Partly cloudy skies are forecast, with just the chance of an isolated sprinkle or shower.

A strong cold front will usher in arctic air and gusty northwest winds Friday. The cold weather will persist this weekend before temperatures rebound next week. (AccuWeather)

Both Toronto and Ottawa are very mild as well, with record warmth expected in both cities today. Ottawa should reach 14C, easily surpassing the record of 10.5C set in 1977, while Toronto is already 15C, expected to reach 19C (66F) today, surpassing their record high of 17.7C set in 2012. The warm air has also broke numerous records across New England, the Ohio Valley and Northeastern US.

As with every spring season since the dawn of time, the warmth won't last. A rather strong cold front will cross the region Friday afternoon, ushering in an arctic airmass. The high on Friday will be reached just after midnight, with temperatures dropping through the day and into the evening hours. The low by Saturday morning will be near -10C (14F). Accompanying the cold front will be scattered showers, changing to flurries, but precipitation should be light. Gusty winds are also expected on Friday and Saturday, in the 30-60km/h range. The wind will make it feel very cold, especially after our current temperatures.

The mild weather this week has very slowly started melting away the deep snow and ice in Montreal. Keep this in mind if you are near any body of water. The ice is already becoming unstable and dangerous.

Milder weather is expected by the middle of next week, but we are also watching a potential storm by the end of the week. Stay tuned, I believe winter is not done just yet.