Feeling a little more like fall

September has been absolutely spectacular in Montreal. The fall colours are now beginning to pop as well around the region.

Our streak of 20C September days came to an end Sunday, after a record-breaking 24 straight, we reached only 19.9C (68F) at Trudeau Airport. However the weather was still spectacular this past weekend, with any hint of precipitation remaining well to our east, and the upper level low staying put over the Great Lakes.

The end result was dry weather over southwestern Quebec, with just an isolated sprinkle or two over eastern Ontario. The heavier rain fell over New Brunswick and Maine, with 70mm in Edmunston and 55mm at the Gaspé Airport on Sunday. 

That aforementioned upper level low will slowly drift over our region early this week, with more clouds than sun and isolated showers finally arriving with it. Precipitation amounts will be on the light side for Montreal. Temperatures will remain mild for late September, rising into the high teens Monday. Overnight lows will remain above normal as well, in the 11C to 13C (52 to 55F) range.

High pressure will become reestablished over the region by Wednesday, with dry weather forecast into next weekend. Temperatures will become more seasonable, with highs between 17C and 19C (63 to 66F) and overnight lows between 7C and 9C (45 to 49F). 

The five day forecast track for hurricane Sam, keeps the storm well offshore of the eastern seaboard. The storm may impact Bermuda later this week, and perhaps Newfoundland by the end of next weekend.  (NHC)

Hurricane Sam

The tropics have been very active this September, with multiple named storms forming. Thankfully, most have remained in the open waters of the Atlantic. Sam is a powerful category 4 hurricane Monday morning, located 1290km east southeast of the Leeward Islands. The storm is moving northwest at 13km/h, with 215km/h winds. Sam is forecast to remain a strong storm for the next day or so before some weakening occurs. At this time, Sam is no threat to land, but the system may impact the coastal waters southeast of Newfoundland by next weekend, with perhaps some weather affecting the Avalon region by late Sunday or early next week.

Perfect Saturday weather - showery Sunday for Montreal

The sharp break in the clouds marks the western edge of a stubborn cold front that has been moving across Ontario and Quebec since Wednesday. The front cleared Montreal early Friday morning after dumping 30 to 40mm of rain overnight. (ValleyWeather Photo)

That had to be one of the slowest moving frontal boundaries I have witnessed in my 40 plus years of weather watching. The front took the better part of three days to move from central Ontario into eastern Quebec. Before the front arrived in Montreal, we were treated to a summer-like day Thursday, with a high of 29C (85F), one degree below the record set back in 1961. The low of 20.3C Thursday morning was the warmest minimum recorded for the date.

The cold front produced a steady north south stream of tropical moisture that dumped very heavy rain over parts of Ontario and Quebec. Flooding was reported in several regions of Ontario, with over 150mm (6 inches) of rain reported at Petrolia. Amounts ranged from 50 to 152mm in Ontario, and 30 to 140mm in Quebec. Windsor reported 99mm, Toronto 62mm and Ottawa 48mm. In Quebec, Gatineau measured 90 to 130mm, the Laurentians 90 to 140mm and Montreal 30 to 40mm.

The rain is over, replaced by a breezy, pleasant Friday afternoon. High pressure will nose into the region overnight resulting in clear skies and low of 13C (55F). Saturday will be a spectacular day, featuring light winds, fair skies and a high of 21C (70F). Make that your day for any outdoor activities, as an upper level low is expected to arrive Sunday and control our weather through the first part of next week. The weather will be showery and cooler, with daytime highs in the middle teens.

Our unseasonable warm September continues, with a high of 21C (70F), Friday marks the 23rd consecutive September day over 20C, adding to the record established earlier this week. The previous record was 19 days, set between September 9 and 27, 2007.

Heavy rain expected to remain west of Montreal

Montreal lies between two weather systems on Wednesday afternoon, high pressure over Atlantic Canada and a strong upper level low over the Great Lakes. Heavy rain is forecast across Ontario along a slow moving cold front, while Southwestern Quebec will remain relatively dry and very mild for late September.

Summer weather persists across southern Quebec Wednesday afternoon, despite the arrival of fall just a few minutes ago. A slow-moving cold front remains well to our west over central Ontario. That front is the focus for torrential rain and thunderstorms. Widespread rainfall warnings are in effect from the Windsor - Toronto corridor into the Ottawa Valley. Some locations are expecting in excess of 100mm (4 inches) of rain over the next 24 to 36 hours, with flash flooding possible

Meanwhile southern Quebec remains on the east side of the system, with a mild southerly flow, and temperatures well-above normal into the middle 20s. The weather has been exceptionally warm this September, with every daytime high over 20C at Trudeau Airport through Wednesday. This is the first time this has occurred since weather records began in Montreal. The average daytime high through Tuesday has been  22.9C (73F), the normal value should be only 20.6C (69F). We have one more warm day to go before the aforementioned cold front arrives.

The front should begin producing rain and scattered thunderstorms late Thursday into Friday in Montreal. Less rain is expected in southern Quebec as the front will be moving at a faster pace across our region. Expect up to 25mm through Friday morning.

The weekend at this time appears a little more fall-like, with cooler high temperatures expected in the upper teens. A few showers are likely as well by Sunday.

Near-perfect late summer weather

The harvest moon will light up the evening sky on election day Monday, rising at 7:55pm in Montreal The Autumnal Equinox occurs Tuesday at 3:20pm. eastern time, heralding the end to summer 2021. The weather will be as perfect as it can possibly be for late September in southern Quebec and Ontario.

Fall officially arrives on Wednesday afternoon at 3:20pm eastern time, and with the exception a few high clouds, summer will end with near-perfect weather. There really is not much to add, strong high pressure is in control of the weather across eastern Ontario and southern Quebec and into Atlantic Canada. Expect clear, warm days, with increasing warmth and gusty winds as the week moves along.

A weak front settled across the region early Saturday morning, but as with just about every cold front this summer, it moved across Montreal with little fanfare, just a drop or two of moisture. Skies quickly cleared out leaving us with a beautiful day, and a high temperature of 24C (76F). 

As a matter of fact, 24C looks like the magic number this week. Expect sunshine through Wednesday and perhaps even into Thursday, with high temperatures either side of 24C. Overnight lows will start off fairly cool, in the upper single digits for some locations, as I write the current temperature is 11C (52F) here on Ile Perrot. By the middle of the week, overnight lows will be very mild under southerly winds, in the upper teens. The normal high/low for late September in Montreal, is 18C (65F) and 8C (48F).

Last Wednesday morning, a line of strong thunderstorms put down a quick 10 to 20mm of rain across the city. However conditions remain rather dry, with only 38.2mm of rain falling this month at Trudeau Airport. The normal for the entire month should be 89mm. The longer nights does mean there is dew present most mornings, which is helping a little.

The next chance for precipitation will arrive by Thursday as a frontal boundary and upper level low move across the Great Lakes and into Quebec. We can only hope this system brings some real rainfall.

Hurricane Larry racing towards Newfoundland

A NOAA satellite image of hurricane Larry located southeast of Nova Scotia and south of Newfoundland Friday afternoon. (NOAA)

Hurricane Larry is expected to make landfall across southeastern Newfoundland late Friday evening. The once category 4 hurricane has been roaming the open waters of the Atlantic for over a week. Larry, now a category 1 hurricane with 130km/h winds, was located 750km southwest of Cape Race, Newfoundland at 2pm Friday afternoon. Larry was racing north, northeast at 60 km/h.

A hurricane warning is in effect for the entire Avalon Peninsula through Saturday morning. Tropical storm warnings are in effect across the Clarenville, Burin and Bonavista regions. Larry is a large hurricane, with hurricane force winds extending outward up to 150km from the center. Forecasters expect the worst of the weather in southeast Newfoundland, including St John's around midnight, lasting through 5AM Saturday morning. Wind speeds are expected in the 110km/h range with gusts up to 140km/h along coastal regions. Winds this strong are capable of knocking down trees and power lines, along with some structural damages. Residents are being urged to prepare for a strong storm through the overnight hours and expect widespread power outages.

Hurricane Larry will rapidly approach the Avalon Peninsula Friday evening while transitioning into a powerful post-tropical cyclone. The center will move towards Greenland on Saturday. (NHC)

Storm surge flooding is possible as well, with large waves accompanying Larry as it races northeast into the north Atlantic. Swells from Larry are already impacting coastal regions from North Carolina to Atlantic Canada. Rainfall from Larry will not be as significant as originally expected due to the rapid movement of the storm, with 30 to 50mm forecast.

Larry is expected to remain a hurricane through landfall tonight and then begin the transition into a strong post-tropical cyclone over the Labrador Sea on Saturday.

Much needed rainfall across southern Quebec

While recent rainfall is helping, water levels remain very low along the St. Lawrence River. This photo was taken last Thursday in Lachine showing just how low the levels are. The lack of rainfall this summer has created difficult and at times dangerous boating conditions in the rivers and lakes around Montreal. (ValleyWeather)

Since September 1st, approximately 25mm (1 inch) of rain has fallen at Trudeau Airport including just under 4mm today. That amount would not be news-worthy, except for the fact that only 36mm fell on the city during the entire month of August. The rain has been a blessing, helping to green things up a little and increase water levels just a touch on area rivers and lakes.

An absolutely spectacular photograph of a waterspout moving inland near Port Albert, Ontario. The photo was taken by storm chaser Mary Ann Williams on Tuesday afternoon. Widespread severe weather impacted southern Ontario along a cold front. @Stormymaryann

A slow-moving cold front is crossing southern Quebec Wednesday afternoon, accompanied by showers and a rumble or two of thunder. That same front produced widespread severe weather in the Huron-Perth and Grey-Bruce regions of Ontario on Tuesday afternoon. There were numerous reports of waterspouts on Lake Huron, as well as tornadoes and hail from Port Elgin to Saugeen Shores. Significant damage was reported to several homes, as well as numerous trees felled and widespread power outages. The front will once again kick up some strong thunderstorms Wednesday afternoon, but only south and east of Montreal across the Eastern Townships and into Vermont. 

We have an unsettled pattern ahead of us in southern Quebec, with a mix of clouds and sunshine Thursday and Friday and the risk of isolated showers or thunderstorms. Friday will be much cooler and dare I say fall-like, with high temperature struggling to reach 18C (65F). Saturday looks pleasant, with a high of 23C (73F) under sunny skies. Clouds and showers return for Sunday.

The forecast track of hurricane Larry will take the center near or over the Avalon Peninsula of southeast Newfoundland late Friday, with winds in excess of 120km/h. (CHC)

Hurricane Larry

Hurricane Larry was located 855km southeast of Bermuda early Wednesday afternoon, moving northwest at 20km/h, with 175km/h winds. Larry is expected to transition into a powerful post-tropical cyclone as the centre nears the Avalon Peninsula of Newfoundland late Friday afternoon. At this time the center is expected to pass near or over southeast Newfoundland, with a period of strong winds, heavy tropical rain and storm surge. Wave heights may reach as much as 15 metres in the Grand Banks. Swells from Larry are already impacting the US eastern seaboard and will arrive in Atlantic Canada over the next 24 hours. The swells and surge are creating very dangerous surf conditions along coastal beaches.

The Canadian Hurricane Centre continues to monitor the progress of Larry, and will likely issue warnings sometime Thursday for portions of southeastern Newfoundland.

Historic flooding sweeps northeast US

Historic tropical rain fell on portions of the northeast Wednesday night, including New York City where widespread flash flooding occurred. Central Park set a new record, with 75mm (3.15 inches) of rainfall in just one hour. The previous record was set just last week during tropical storm Henri. (Anthony Behar/CNN)

After devastating the Louisiana Gulf Coast, what was left of hurricane Ida swept across the northeastern US on Wednesday, with historic flash flooding and tornadoes. The severe weather was responsible for at least 8 deaths in the metropolitan New York region and  neighbouring New Jersey. The water came fast and furious, with 125 to 225mm (5-9 inches) of rain falling in just a few hours.

The record setting tropical downpour had nowhere to go, with neighbourhoods flooded and homes swamped. Highways flooded rapidly and the New York City subway came to a halt in partially submerged tunnels trapping commuters. First responders were forced to make numerous rescues. A state of emergency has been declared in both New York and New Jersey.

Earlier in the day powerful thunderstorms produced large tornadoes over portions of Maryland and southern New Jersey. Numerous communities were impacted, with several homes destroyed. The death toll from Ida sits at 16. 

What is left of the system is located near Cape Cod early Thursday morning, moving northeast towards Nova Scotia. Rainfall warnings are in effect for portions of Atlantic Canada, with 40-60mm forecast along with embedded thunderstorms and gusty winds.

Welcome to meteorological fall

A NOAA satellite image taken Wednesday showing the remains tropical depression Ida over the northeastern US. With the exception of a few high clouds, most of the sensible weather will remain well south of Montreal and Quebec. Ida will likely spread rain into Atlantic Canada by Friday. After devastating the Louisiana Gulf Coast, Ida has produced flash flooding and tornadoes along the storms entire path through the Tennessee and Ohio Valleys. (NOAA)

Fall, at least according to meteorologists, has arrived. September 1st marks the the first day of meteorological fall, the celestial equivalent will arrive on Wednesday, September 22. So statistically speaking, the warmest three months of the year are behind us. It was an odd summer for sure, a rather coolish July, bookended by two scorching dry months and very little thunderstorm activity in Montreal.

Taking a brief look at August, it was hot and dry in Montreal. The average temperature was 23.6C (74.5F), well above the normal of 20.1C (68.2F). Total rainfall was 36.1mm, which is significantly below the long-term average of 94.1mm. For the year, Montreal has received 476.7mm of precipitation, which is 73% of normal to August 31. We managed two distinct heatwaves resulting in 13 days over 30C (86F). Dozens of new temperature, dew point and humidity records were established in August at Trudeau Airport.

We are off to an average start in September, with partly sunny skies and high temperatures expected in the low to middle 20s through Saturday. The dry weather will persist, with no precipitation expected until Sunday at the earliest.

A National Guard convoy rolls through the New Orleans suburb of LaPlace on Monday looking for victims of the fierce hurricane. (NOLA.com)

Hurricane Ida

The remains of Hurricane Ida, now a depression with 30 mph winds, are moving through the northeast US today and Thursday. All the weather associated with Ida will remain well south of Montreal, with partly cloudy skies expected this afternoon from the northern edge of the cloud shield associated with Ida. Ida is expected to produce heavy rain and flash flooding across portions of the northeast and southern New England, including metropolitan New York City. 

In Louisiana, the clean up is underway after Ida produced catastrophic wind damage and widespread flooding. Damage is estimated in the billions, with many homes destroyed and no running water available in many locations. This is especially true in the Parishes south of New Orleans towards the Gulf of Mexico. Over 1 million homes remain without power, with crews from 22 states arriving to assist in the restoration. The National Guard and FEMA are on the ground helping residents. All this is taking place as temperatures soar over 90F (32C), with heat index values over 100F (37C).