Major flooding in southwest Ontario and Michigan

A state of emergency has been declared in Essex County, Ontario after two days of torrential rain. (Windsor Star)

A stubborn upper-level low stalled over the Ohio Valley continues to pump deep moisture off the Great Lakes, across southwest Ontario and Michigan. On Thursday, more heavy rain fell across the area, with nearly 160mm in Tecumseh, south of Windsor. Officially, 85mm fell at Windsor Airport, with over 120mm in nearby Detroit. The normal rainfall for the entire month of September is 91mm in Windsor. The rain produced widespread flooding on roadways and in basements. Rivers are on the rise as well, with many exceeding flood stage. A state of emergency has been declared in Essex County, Ontario. More rain is forecast today, with another 50-75mm possible. Across the river in Detroit, the situation was much the same, with major highways closed and water rescues underway. The storm causing the rain will slowly drift southeast before lifting north again this weekend. Cloudy skies and showers are forecast across the Northeast, New England, southern Quebec and Ontario. The heaviest rain will remain south and west of Montreal.

Hurricane Matthew
Matthew strengthened into a hurricane on Thursday, with the center located 535 miles southeast of Kingston, Jamaica Friday morning at 5:00 a.m. Matthew is moving west at 14mph, with 100mph winds. Additional strengthening is expected today, and Matthew could become a major hurricane. The forecast track will take the system west for the next 36 hours before turning north towards Jamaica and Cuba by late Sunday. By the middle portion of next week, Matthew is forecast to be near the Bahamas. The storm may then threaten the east coast of the US and Canada, but it is too soon to determine where and to what extent. Additionally, the possibility does exist that the storm could be swept out to sea, missing the east coast.

September warmth to continue into October

A slow-moving upper-level low pressure area will persist across our region through the weekend. Montreal will remain on the edge of the system with frequent clouds and showers, but also some breaks.

According to the National Oceanic and Atmospheric Administration (NOAA), August was the 16th consecutive month with temperatures above average globally. This has not occurred over the last 137 years; basically, it has been exceptionally warm. August was 1.66F above the 20th Century average, eclipsing the record set just last year. The average temperature for 2016 to date is 1.82F above the long-term average. In Montreal, we experienced the second-warmest June-to-August period on record. The warmth continued into September. So far, the monthly average is 17.8C, above the normal of 15.5C. It has been extremely dry once again, with only 31.2mm of rain this month, compared to the normal of 83.1mm.

For the short term through the start of October, we are expecting temperatures to remain slightly above average. Stubborn low pressure will very slowly move from the central Great Lakes southeast towards southern New York. The system will then lift north again into eastern Ontario. Southern Quebec should remain on the periphery of the moisture, with showers forecast Saturday and Sunday, but not a washout. Gusty northeast winds will prevail through the end of the week as well, making it feel a little cooler than the advertised highs. Several mornings this week have featured a marine layer of clouds and fog generated by the northeast winds channeling down the St. Lawrence Valley.

Tropical Storm Matthew
Tropical storm Matthew has formed in the Atlantic Basin, 40km southwest of St. Lucia. Matthew is moving west at 20mph (31km/h), with 60mph (100km/h) winds. This storm is forecast to strengthen and become a hurricane by Friday. Forecasters then expect Matthew to turn to the north and impact Jamaica. Beyond then, there is the potential the storm could affect the Gulf Coast or even the eastern seaboard.

Summer snow for Lake Louise, warm in Montreal

Heavy wet snow greeted visitors to Lake Louise, Alberta on the last full day of summer. (Lake Louise Ski Resort Photo)

The last full day of summer was spectacular across southern Quebec and Ontario. Plentiful sunshine, gusty southwest winds and warm temperatures prevailed, with highs reaching 27C (80F) or better in many locations across southwestern Quebec. Humidity levels were elevated, making it feel more like mid-summer. Montreal should be around 20C (68F) for late September. While we were enjoying August-like weather here in the east, an upper-level low and cold northerly flow produced a widespread summer-snowfall across the foothills of Alberta. As much as 32cm fell across the higher elevations near Banff, with over 30cm at Sundre. A cold rain fell east of the foothills towards Calgary.

The coolest air so far this September will invade southern Quebec this weekend. (AccuWeather Graphic)

First Day of Autumn
Fall officially arrives at 10:21 a.m. Thursday morning, with cooler weather and clouds forecast to greet the season. Today will still feature above-normal temperatures in Montreal, just not as warm as it has been. Expect high temperatures in the low to middle 20s. A cold front will move from north to south across southern Quebec tonight and into New England on Friday. Expect a period of steady rain along the front, followed by gusty north winds and much colder temperatures. Highs on Friday will only be in the upper teens. High pressure will settle into Quebec Saturday and remain through Monday. The forecast will be cooler than normal for the first time this month. Highs on Saturday and Sunday will only be around 15C (59F), with lows down to 7C (45F) in the city, but much colder in outlying regions. Some locations may even see scattered frost early Sunday and Monday morning. Briefly looking ahead to next week, warmer weather will return, with temperatures once again surging above normal in Montreal.

Warm September continues across southern Quebec

Warm, muggy weather will dominate the east coast and southern Quebec once more this week. (AccuWeather)

The hot and dry summer across southern Quebec has stretched right into September. With two thirds of the month in the record books, the average high temperature has been a sweltering 24.3C (76F), the normal should be 20.6C (69F). To date 18 of the 19 days in September have featured above normal temperatures. This trend continues Monday morning, with Montreal at 9 a.m. reporting 21C (70F), the warmest location in the country. Partly sunny skies and humid conditions are forecast today through Wednesday, with high temperatures well above normal at 26C (79F). The normal high for September 19, should be 18C (65F) for Montreal. With the exception of a couple of nights, the overnight lows have been very mild as well, averaging 13.5C (55F), the normal should be 10.3C (50F).

There has been a slight improvement in the drought conditions in southern Quebec after the rainfall of late August. September however has been very dry once again, with only 23.4mm of precipitation so far. Montreal normally receives 83.1mm of rainfall for September. We have plenty of catching up to do. Showers and thunderstorms over the weekend missed Montreal, with only 3 or 4mm falling in the city. The next chance for rain will come along a cold front Thursday. Cooler, more seasonable weather is expected to arrive by next weekend. However it will be short lived, as the much warmer than normal Great Lakes continue to modify the cooler fall air as it moves southeast from northern Canada.

Spectacular Harvest Moon Friday night in Montreal

The full Harvest Moon rises over the St. Lawrence Seaway in September 2015. (ValleyWeather Photo)

Another chilly morning greeted early risers on Friday, as temperatures settled into the middle single digits across southern Quebec, 6C (43F) here on L'Ile Perrot. Some locations across the Adirondacks and Laurentians dropped very close to the freezing point, with scattered frost reported. We can expect another sunny day, with seasonable temperatures of 22C (72F) here in Montreal. The weekend is looking unsettled, as a moisture-laden frontal system approaches Quebec form the Great Lakes. We can expect increasing clouds Saturday, followed by showers and thunderstorms through Sunday. Temperatures will be rather mild, with highs in the middle 20s and lows in the teens. Winds will be gusty both days this weekend.

HARVEST MOON
The Harvest Moon is the full moon closest to the Autumnal Equinox. Fall arrives on September 22 at 10:21a.m. ET, making Friday night's full moon this years harvest moon. The Harvest Moon has always been the biggest, brightest and earliest-rising full moon in the sky all year long, appearing shortly after sunset. Through the year's, farmers have relied on that moonlight to lengthen the short work days of late summer and early fall, allowing them to continue with the harvest late into the night.

This year, some will be treated to an additional celestial show. The full Harvest Moon will also feature a Penumbral Lunar Eclipse. While not as spectacular as the full lunar eclipse in September 2015, it should still be a sight to see. The moon will take on a spooky glazed look as it passes through the Earth's shadow. While conditions will be clear in eastern Canada, the eclipse happens early in the day and will not be visible here in Montreal. The full moon rises at 7:12 p.m. in Montreal. The eclipse will be visible across Europe, Africa, Asia, Australia and the Western Pacific. It will last 3 hours and 59 minutes, reaching its peak at 18:54 UTC (2:54 p.m. in Montreal).

A touch of fall in the air for Ontario and Quebec

A tree crushes a car in north end Montreal early Sunday morning. (CTV News Montreal)

Monday morning Southern Quebec awoke to a fresh air mass and the coldest temperatures since last May, 9C (48F) here on L'Ile Perrot. This comes after an active weather weekend across eastern Canada. Saturday was extremely humid, with summer-like temperatures rising into the high 20s and, in some cases, over 30C. Combined with the humidity, the atmosphere was juiced as a strong cold front arrived overnight into Sunday. The front generated widespread severe thunderstorms that swept across the St. Lawrence Valley from Kingston to Montreal and northeast towards the Saguenay. Winds gusted in excess of 70km/h in Kingston and Brockville, with a 69km/h gust reported at Trudeau Airport in Montreal. The wind toppled numerous trees onto cars and homes. Power lines were also damaged, with 60,000 Hydro Quebec customers across the province without power at the height of the storm. Over 150 crews and contractors worked through Sunday restoring power. As a result less than 1000 customers remain in the dark as of Monday morning. The thunderstorms also produced spectacular lightning in and around Montreal through the wee hours of Sunday morning, with over 30 strikes per minute in some cases. Funnel clouds were observed in southeastern Ontario, prompting a tornado watch.

A spectacular shot, taken by Kingston Police, of  lightning accompanying one of the storms Saturday night in Kingston, Ontario.

The front ushered in the first real fall-feeling air mass of the season. Temperatures remained in the teens on Sunday here in Montreal, along with a brisk northwest wind. This morning, skies are clear and it is fresh to say the least. The temperature dropped to 11C (52F) at Trudeau Airport, 9C (49F) here in Vaudreuil/Dorion, but as cold as 3C (39F) across the Laurentians and Adirondacks. The start of the week will be perfect, with lots of sunshine, low humidity and temperatures in the middle 20s. Clouds, along with showers and thunderstorms, arrive Wednesday, before conditions improve Thursday. Temperatures will cool once again to end the week.

Late-summer eastern heatwave

Tropical depression Hermine continues to dissipate off the east coast, while warm and humid air flows north into eastern Canada. (AccuWeather Map)

It feels like mid-August this morning in southern Quebec, with the current temperature already higher than our normal daytime high for early September. Montreal is currently 22C (72F), on our way to a high of 28C (83F). The overnight low was 21C (70F), over 10 degrees Celsius above normal. It is very muggy out after 4.2mm of rain overnight. Wednesday was sunny and hot across most of eastern Canada, from Ontario to Newfoundland. Montreal was nearly 30C (86F), while Toronto set a new high temperature record for the date at 35C (95F). The previous record dates back to 1960 at 33.9C (94F). New high temperature records were also established right across Atlantic Canada, including Newfoundland. Badger, Newfoundland recorded a new record high of 27.4C (81F). In Grand Manan, New Brunswick, the mercury hit 25.3C (78F) to tie the record for the date. Data at that location dates back to 1883, so this is significant warmth we are experiencing for September.

The webcam at Sunshine Village near Banff, Alberta, shows an early-season snowfall on Wednesday. (skibanff.com)

For those looking for cooler fall weather, you may have to wait another week or so, or travel to western Canada. Low pressure and a cold front will give Montreal a breezy, muggy day today, with showers and thunderstorms. Skies will clear briefly on Friday, but the weather will remain warm and a little humid. Another round of showers and thunderstorms is likely Saturday afternoon into Sunday, before high pressure returns. Sunshine will prevail to start next week. Temperatures in Montreal next week should remain well above the normal high of 21C (70F) and normal low of 10C (50F). The current heatwave covers most of the eastern United States as well, with high temperatures in the upper 80s and 90s and heat index values above 100F (37C) from the deep south into New England.

Meanwhile it is much cooler out west. Snow fell on Wednesday at Sunshine Village near Banff, as the temperature was just above the freezing point. More snow is possible next week, as a strong cold front is forecast to sweep the region.

Hermine blasts the Outer Banks - spares Jersey Shore

Major flooding was reported on Hatteras Island, North Carolina this past weekend from tropical storm Hermine. (TWC)

After hammering the Outer Banks of North Carolina through Sunday morning, Hermine is drifting slowly north this morning, 305 miles southeast of Long Island, New York. The Jersey Shore is breathing a cautious sigh of relief on this Labour Day Monday, having been spared so far. The storm continues to show signs of strengthening, currently with 70mph winds. Tropical storm warnings are posted for the Long Island coast, as well as eastern Massachusetts. High surf advisories are posted northwards into New Hampshire and Maine. Interests in Nova Scotia and coastal New Brunswick should continue to monitor Hermine.

Highway 12 on Hatteras Island, North Carolina, under water on Saturday, September 3. (AP Photo)

This storm has been difficult to forecast since day one. Hermine is expected to meander off the east coast through at least Wednesday, before moving northeast, south of Atlantic Canada, and out to sea. The threat for heavy surf continues today for the northeast US coastline from Delaware to Maine, but little inland effects are expected at this time. The catastrophic flooding forecast for the Jersey Shore has not materialized at this time. However there is still a risk of high surf and flooding at each high tide through mid-week from New Jersey northward. Residents are urged to continue to monitor this fickle storm.

Hermine is blamed for at least two deaths, one in Florida and a second on the Outer Banks. The storm blasted the Outer Banks on Saturday, with winds in excess of 80mph and severe flooding. Water was 5 feet deep in several villages on Hatteras Island after the Pamlico Sound spilled onto the island on the back side of Hermine. Roads were submerged and homes and businesses took on water. Conditions are slowly improving on the Outer Banks today, as crews begin yet another major clean-up of coastal Highway 12. Further north, dunes were destroyed in Nags Head and Kitty Hawk, with severe beach erosion reported.

Montreal
Meanwhile, the weather is perfect here in southern Quebec. What you see is basically what you can expect through mid-week. Strong high pressure is keeping Hermine off the coast, providing spectacular sunshine and warm temperatures in the upper 20s. This is followed by cool, crisp nights, with lows in the lower teens.

Hermine expected to batter US east coast for days

Hurricane Hermine caused major damage along the Florida Gulf Coast Friday morning before moving north into the Carolinas. (TWC/Getty Images)

Tropical Storm Hermine is going to be kept at bay to our south this weekend, by strong high pressure centered over Quebec. That high pressure will provide sunny, tranquil weather for southern Quebec and northern New England. Further south along the southern New England and Mid-Atlantic coasts, it will be a very different story.

This morning, Hermine is located 60 miles west northwest of Hatteras, North Carolina. The Outer Banks took a beating overnight, with heavy rain, in excess of 125mm (5 inches), as well as 60 mph winds and pounding surf. A tornado was reported on Hatteras Island, damaging a campground with minor injuries reported. From Florida to Virginia, hundreds of thousands are without power. So far one fatality has been reported from Hermine. Tropical storm Hermine is expected to move off the coast back into the open waters of the Atlantic later today. The storm will undergo some rather technical transformations over the next 24 hours, however she will remain a very dangerous storm. With the lessons learned from Hurricane Sandy, the National Hurricane Center will continue to provide updates on the storm, regardless of whether she is tropical, post-tropical or extra-tropical.

The projected track of Hermine has her stalling off the Jersey Shore this weekend. (NHC)

Call her what you want, the coast from Delaware to Long Island will be hammered for days during successive high tide cycles. The fear is for Sandy-like damage to coastal infrastructure in many locations. This holds especially true for the Jersey Shore. The storm will meander off the coast through at least Tuesday and perhaps longer before being swept out to sea.

 I will provide frequent updates on Hermine throughout the holiday weekend via twitter @valleyweather2 and this blog. Stay safe.