Friday, October 31, 2014

Happy Halloween - dry for metro Montreal

Schultz image
It looks like the weather will be decent for trick or treating in Montreal. Low pressure developing over the Great Lakes will produce light rain and snow for portions of Ontario today including Toronto. While it will be a cloudy, cool day in the St. Lawrence Valley, any shower activity should stay away from metro Montreal until after midnight. Temperatures are chilly today, at 0C (32F) right now here on L'Ile Perrot. Look for a high near 7C (45F) with temperatures around 5C (41F) during the trick or treating.

The Great Lakes low will move south of Montreal and off the Atlantic seaboard by Saturday where it will combine with another disturbance and develop a potent Nor'Easter. This storm system will guarantee a windy, chilly and gray weekend for Montreal, but no snow expected at this time as it remains well offshore. The snow will be confined to the Gaspe region of Quebec as well as interior Maine and New Brunswick. A stray snowflake or two may develop over the Townships late Saturday.

Have a safe and Happy Halloween!

Thursday, October 30, 2014

Potential storm to pass south and east of Montreal

The stalls were full and customer traffic was steady all day Wednesday at Gordons in N.D.G. The annual rush to get snow tires on and have the car tuned before the snow flies is well underway. Customers were lined up before the 7am opening on Wednesday morning and it will be the same for the next month. (ValleyWX Photo)
It looks like our first shot at snow for the 2014-2015 season will just miss Montreal. A cold upper level low will dive south from the Great Lakes into the Ohio Valley on Friday before moving off the middle Atlantic coast Saturday. This system will then develop into a strong Nor'Easter and move towards Atlantic Canada by Sunday. The path of the low will keep it well offshore, far enough to spare Montreal from any significant weather. However, if you have friends or family in interior New Brunswick, they may see a decent snowstorm on Saturday night with rain changing to wet snow. The same is possible across eastern interior New England depending on the track of the low.

At this time the weather looks grey and cool in Montreal with perhaps a stray shower for trick or treating on Halloween night. Temperatures will be around 5C (41F), so dress the ghosts and goblins up well. Until then expect mostly cloudy skies, typical October weather, with a cool gusty wind. The high temperature today will be near 8C (47F). The weekend forecast will feature clouds on Saturday with a cold north wind gusting to 40km/h and perhaps a few showers or a stray snowflake in the mountains, highs only near 5C (41F). Sunday will be partly sunny and cold with highs near 4C (39F). Overnight lows this weekend will range from 0 to -3C (26-32F), so frost and a freeze will occur.

Monday, October 27, 2014

First snowflakes may fly in Montreal by Halloween night

Say it ain't so! The first snowflakes of the season for the St. Lawrence Valley may be in the air as early as Halloween night or Saturday morning. Before then we can expect a mild but unsettled week as low pressure forms over the Great Lakes and moves northeast towards Hudson Bay. It will lift a warm front across southwest Quebec this evening followed by the cold front late Tuesday. Showers will develop this evening and again late Tuesday. In between we can expect some sunny breaks along with a mild push of air on gusty southwest winds. That should help temperatures to rise to 12C (54F) today and up to 16 to 18C (60-65F) on Tuesday. Overnigh lows will be around 6C (43F).

Enjoy the mild weather as the coldest air of the season is forecast to arrive by Friday night. An upper level low will help pull down the cold air by late in the week with rain showers on Friday changing to flurries or snow showers late Halloween night and tapering off Saturday. Some areas may see a coating of snow, especially across the Laurentians and Townships. We will have to monitor the systems development as the week moves along. Temperatures will only be 6C (43F) for a high Friday with a low dropping into the minus 3C (26F) range by Saturday morning. Frost or a hard freeze is likely this weekend everywhere. In any event the last week of October is always the time I head over to Gordons Service in N.D.G. to get the winter tires on and this year is no different. Time to put the winter preparations into to full gear, once we are on the other side of Halloween, we are at the mercy of the seasons.

Wednesday, October 22, 2014

The 60th Anniversary of Hurricane Hazel in Toronto

It is another chilly, raw morning in Montreal and the St. Lawrence Valley. The current temperature is 7C (45F) but with a gusty northeast wind over 40km/h it feels much colder. A developing Nor'Easter, yes it is that time of year again, will push Atlantic moisture into southern Quebec on Thursday. It will be a very windy, rainy and raw day with the high around 8C (47F). No sunshine is expected before Sunday.

This past October 18 was the 60th anniversary of the arrival of Hurricane Hazel in southern Ontario. Hazel developed in what was already a very busy hurricane season that summer/fall of 1954. 1954 was the first season that forecasters at the National Hurricane Center were using names to identify storms. The "H" storm formed in the open waters of the eastern Atlantic 50 miles east of Grenada on October 5 and began a two week journey into the Carolinas and eventually Ontario. The storm made landfall as a powerful category 4 hurricane along the North and South Carolina border with a devastating storm surge and 150mph winds. Hazel would kill 92 in the US as well as over 1000 in Haiti. But it was the unexpected ferocity with which she arrived in southern Ontario around midnight on October 18 that captured Canadians' attention from coast to coast. October 1954 was very wet in and around the GTA, and as they say in meteorology, timing is everything. And so it was with Hazel. Within 12 hours, the storm morphed from a tropical system to a rather intense post-tropical cyclone. Hazel arrived on already soaked ground with a deep intensifying atmospheric trough colliding with the storm. The result was torrents of rain along and around the Humber and Don River watersheds. The Highland Creek, Credit River, Humber, Don, Etobicoke and 16 mile creek would all overflow their banks by midnight on October 18. The forecast for Hazel put an emphasis on the wind, when in reality most of the strong gusts occurred across eastern Ontario and western Quebec. Instead heavy rain fell on the western GTA with 183mm at Toronto City, 127mm at Islington, 107mm in 12 hours at Malton (now Pearson Airport). An incredible 214mm fell in Snelgrove and Brampton including 90mm from 9pm to midnight on October 17, 1954. The result was absolutely catastrophic with a torrent of water racing down the Don and Humber Rivers washing away everything in sight, houses, cars, people. The Humber River from Brampton down to Lake Ontario rose over 10 feet in hours and flowed at an astonishing 1416 cubic metres per second. Hard hit Raymore Drive along the Humber River was washed away with 31 lives lost and over 40% of the street destroyed.

Swift and deadly flash flooding took 31 lives on Raymore Drive alone during Hazel in 1954. (Toronto Star)
The tragedy changed both the way we look at tropical systems in Canada and more importantly for the GTA, the way rivers and stream are monitored and how closely we build residential areas to them. The Toronto and Region Conservation Authority was established shortly after Hazel to help monitor that. Additionally the Dominion Weather Office, (predecessor to Environment Canada) took criticism for how the forecast was handled. In reality Fred Turnball, Head of the Dominion Weather Office at Macton, had predicted that morning  the rain from Hazel could very likely be the heaviest on record for Toronto. He was right, his message was just not delivered properly to the public. Even at that, it might not have made any difference for those who were sleeping in the wee hours of October 18, 1954 when the water came rushing through with such speed and ferocity. In the end 81 people would die as a result of Hazel in Canada, including 5 firefighters from Etobicoke whose rig was washed away by the Humber River. Nearly 1900 were left homeless, and damages would exceed 125 million. You can read about the firefighters and other personal accounts at this link HAZEL.

Monday, October 20, 2014

Cool & wet weather week ahead for Montreal

It most definitely feels like fall this morning as temperatures have dropped from highs in the upper teens on Saturday to 0C (32F) this morning, here on L'Ile Perrot. Despite it being cold, it is a dry morning and should remain that way for today. That however is the extent of the good news for this week. All I can say is that it will be a typical week for middle October. After a high of 10C (50F) today with partly cloudy skies, we can expect clouds to thicken tonight. Low pressure will move from the Ohio Valley to New York City and become nearly stationary. An easterly flow of moist Atlantic air will almost guarantee cloud cover along with periods of rain through Thursday. Temperatures will not fluctuate much from lows to highs, generally in the 8 to 11C (48-52F) range. Rainfall may be significant in some locations especially closer to the US border with forecast amounts between 25-75mm (1-3 inches) by the end of the week.
Heavy rain from Gonzalo in St. John's, Newfoundland on Sunday morning. (Canadian Press Photo)
Post tropical storm Gonzalo is on the way to the United Kingdom this morning, moving rapidly across the north Atlantic, as a strong ocean storm. The once category 4 hurricane brushed by the southeast coast of Newfoundland in the wee hours of Sunday morning. A short period of very heavy rain dumped between 50-75mm (1-3 inches) on the eastern portion of the province with 69.1mm at Mount Pearl and 51.6mm  at St John's. Winds were very strong, especially offshore with a gust to 158km/h reported on a Hibernia Rig (Ocean VEP 717) on the Laurentian Fan. That wind elevated seas to over 10 metres (30 feet) offshore with some large waves crashing against the coast. A top wind speed of 74km/h was observed at St John's Airport with 100km/h at Cape Race. Minor flooding was reported but not much in the way of damage. The storm was over in just a few hours.

A spectacular shot of Cape Race after Gonzalo on Sunday morning. (Twitter @StormhunterTWN)

Saturday, October 18, 2014

Hurricane Gonzalo heads for Newfoundland

An incredible radar image from the Bermuda Weather Office of the eye of Gonzalo swallowing the tiny island of Bermuda last evening.
The big weather story this morning will be the arrival of Hurricane Gonzalo very close to the southeast coast of Newfoundland by early Sunday. A tropical storm watch is now in effect for the coastal regions of southeast Newfoundland. Gonzalo this morning is about 1450km south, southwest of Cape Race, Newfoundland moving north, northeast at 22km/h. The storm has winds of 100mph with a central pressure of 958mb according to the National Hurricane Center. Environment Canada has Gonzalo passing within a radius of 150km of the coast early Sunday morning. The storm will be transitioning into a post tropical storm at the time but still capable of 10 metre (30 foot) seas along the coast and winds up to 100km/h (60mph). Rainfall will be intense but fairly limited due to the rapid speed of the storm. Still, heavy rain bands could produce up to 25mm (1 inch) per hour for a few hours along the Avalon. In the shipping lanes of the Laurentian Fan into the southern Grand Banks the storm will have an intense impact. Hurricane force winds will whip seas as high as 16 to 18 metres (50-60 feet) according to the Canadian Hurricane Centre.

Crews respond to the thousands without power on Bermuda after Hurricane Gonzalo made a direct hit. (The Royal Gazette)
Meanwhile crews are out removing thousands of downed trees and restoring power to over 32,000 homes on Bermuda. Gonzalo made a direct hit on the tiny island nation of 64,900 in the vast Atlantic Ocean last evening with winds in excess of 100mph. Flooding and a coastal storm surge was also reported. Roads are blocked across the island. Structural damage to several buildings including a hospital was reported. No reports yet of casualties from Gonzalo.

Friday, October 17, 2014

Hurricane Gonzalo heads for Bermuda - flooding in GTA

Bermuda weather radar showing the eye of Gonzalo nearing the tiny island (plus sign) this afternoon.
 There is plenty to talk about this morning, so I am putting the Hurricane Hazel column off for a few hours. Lets start in Ontario and Quebec where very warm and moist air produced lots of heavy rain on Thursday. The rain along with tons of falling leaves clogged sewers across Toronto producing lots of flooding. The flooding disrupted the evening commute in what is becoming an all too familiar occurrence. Underpasses were flooded with motorists stranded. In addition several subway stations took on water as well. Pearson Airport recorded only 5.2mm on Thursday but other locations in the GTA had between 50 and 100mm (2-4 inches) of rain in just a few hours. It was the same in southern Quebec with Trudeau Airport recording 8mm of rain, but I managed 15mm here on L'Ile Perrot and amounts ranged over 25mm (1 inch) in other parts of the region as thunderstorms occurred.

Flooding from heavy rain in portions of the GTA late Thursday. (Toronto Star)
Showers will continue today and into the weekend in Montreal as it turn sharply colder. Temperatures were in the low 20's again on Thursday but will drop to the teens today (17C) and single digits by Sunday when the high will only be 8C (47F).

The latest National Hurricane Center forecast has Gonzalo coming very close to eastern Newfoundland early Sunday.
Gonzalo remains a major hurricane this morning with winds up to 130mph and a pressure of 946mb. The storm is located 240 miles (385km) south southwest of Bermuda while moving north northeast at 15mph. On this present course the hurricane will arrive very close to Bermuda late today. Winds at 7:30 were already over 60km/h (38mph) on the island. Heavy rain, in excess of 150mm (6 inches) along with dangerous winds and a powerful storm surge will arrive shortly. Once the storm moves past Bermuda it will begin to slowly weaken and transition into a powerful post-tropical storm. Winds and rain will begin to affect Atlantic Canada coastal waters by Saturday afternoon. It is still early to pinpoint the exact impact on Newfoundland, but heavy rain is likely along the southeast coast along with heavy surf. High surf is also forecast for Nova Scotia. Strong winds may impact the Avalon Peninsula if Gonzalo makes landfall in Newfoundland. The current NHC track has the storm remaining offshore.