Heat warning remains in effect for Montreal

A spectacular photo of the intense lightning taken by Quebec Vortex last night on the South Shore in La Prairie.
More on Quebec Vortex at this link. 

Our longest and hottest heatwave of the summer is moving into its 5th day in Montreal with temperatures expected to reach 32C (90F) today. If it does, it will set a record high for the date, the previous being 31.7C (89F) in 1960. Yesterday Trudeau Airport had a poorly timed shower around 4pm, enough to drop the temperature down a degree or two, preventing us from a record high by a few tenths of a degree. The official high was 31C (88F) but most other reporting stations around the island including here on L'Ile Perrot, reached 33C (91F).

The airport is typically cooler as the breeze off Lac St. Louis can knock the temperature down a couple of degrees. It remained very warm and muggy overnight with lows in the middle 20's. Last evening a spectacular thunderstorm with lots of vivid lightning moved from the South Shore across the downtown area around 10pm. The storm dumped only 2mm of rain here on L'Ile Perrot but 5mm at the airport in Dorval and 20mm downtown at the McTavish station.

High pressure off the US east coast will continue to pump warm and humid air north into southern Quebec today. The heat advisory remains in effect as humidex values are forecast to exceed 40C (104F) this afternoon. As with Tuesday, there remains a risk of thunderstorms this afternoon and evening. Tonight will be muggy again with warm overnight lows of 24C (76F) in the city. On Thursday a cold front will approach eastern Ontario and western Quebec with showers and thunderstorms by late in the day. It will be warm again with a forecast high of 30C (86F). Cooler air with lower humidity arrives by the weekend.

Heat warning in effect for Montreal

Warm and humid air streaming north into southern Quebec will make it feel close to 40C in Montreal. (AccuWeather.com)

Some of the warmest air this summer is streaming north into southern Ontario and Quebec. It has been hot right across the country with temperatures well into the 30's and even pushing 40C (104F) in western Canada. Montreal officially managed 29C (85F) at Trudeau Airport on Sunday but it was well over 30C in most other locations away from the typically cooler airport. The high temperature reached 31.5C (88F) at my home on L'Ile Perrot, as well as in St Anicet, Ottawa and Cornwall.

As the heat and humidity continues to build in the east, heat warnings have been issued across Ontario and southwest Quebec. Typically they are posted when a combination of the warm temperatures and elevated humidity make it feel warmer than 40C. It will be that way to start the week for Montreal, Ottawa and Toronto. Hazy sunshine will dominate the weather with perhaps some scattered thunderstorms by Wednesday. High temperatures will range from 30 to 35C (86 to 95F) across the region. Overnight lows will remain warm near 21C (70F). We can expect these conditions through Thursday.

A massive wildfire burning out of control near Oliver, B.C has forced hundreds of evacuations.
(Photo via twitter @stucktweet)

B.C. Wildfires
In British Columbia, the hot and bone dry weather has been accompanied by sporadic lightning. Numerous major wildfires have developed over the last week including the Rock Creek fire near Oliver, B.C. This fire, which may have been started by a single cigarette, has consumed more than 3,750 hectares and is 0 percent contained. The fire has forced the evacuations of more than 600 residents and destroyed 30 homes. Since April over 1600 fires have been reported in tinder dry B.C., most of those in the southern interior and Okanogan Valley. The fires have burned over 290 square kilometers. Fires are also burning in neighbouring Washington Sate. Some relief in the weather is expected this week with cooler temperatures and lighter winds as well as less lightning.

Hot weather returns to Montreal this weekend

The heat and humidity will build as we head into this weekend with highs reaching 30C in Montreal. (AccuWeather)

It has been a rather soggy start to August across southern Quebec. I recorded nearly 36.6mm of rain at my home on Tuesday alone, with 47mm at Trudeau airport. The heavy rainfall of the last 48 hours has brought the monthly total at Trudeau Airport to 87mm. This is well above normal for August and nearly a full months rain in just the first 12 days. The long term average for Montreal is 94mm for the entire month of August. The forecast for the next couple of days will see a chance for more showers and thunderstorms, especially Friday afternoon. Afterwards we will begin to see an increase in temperatures as we head into the upcoming weekend. Sunshine both Saturday and Sunday will push the mercury up to 30C (86F) across southern Quebec. By Monday we may even see a few low 30's for highs, close to 90F from southern Ontario into Quebec and New Engalnd.

WESTERN HEATWAVE
The heat is already building across western Canada. On Wednesday, Lytton, BC had a record high of 40.2C (104F) surpassing the old high of 39.7C. Estevan, Saskatchewan was 36.7C (98F), and Regina 32.9C (91F). The heat will remain into Saturday for the west with highs reaching well into the upper 30's with perhaps an isolated 40C. A strong cold front will bring an end to the heatwave out west by Sunday as it races across the Prairies and into Ontario and Quebec by next Tuesday. Strong to severe thunderstorms are likely with this front as it marches east across southern Canada.

Heavy rain forecast for southern Quebec

Low pressure will move across southern Quebec Tuesday with heavy rain forecast. (AccuWeather)

It was not a terrible weather weekend across southern Quebec, but still far from perfect. There was more sunshine than I expected on Saturday and far more cloud cover on Sunday. Both days featured spectacular starts to the day, but in that unseasonably fall like atmosphere we seem to have lately, clouds and even fog developed by mid-morning and remained in one form or another the rest of the day. Sunday afternoon was the best period, at least here on L'Ile Perrot, as skies cleared and we hit 29C (85F).

The sunset Saturday night in Vaudreuil resembled a painters canvas. Plenty of moisture in the atmosphere lately has created some very busy skies during the day, with rapid clearing at sunset. (ValleyWeather Photo)

As we start another work week, Montreal can expect a mostly sunny day (fingers crossed), along with warm high temperatures near 28C (83F). Enjoy today because the rest of the week looks rather unsettled and at times dismal. Developing low pressure over the US Midwest will move from Lake Erie down the St. Lawrence Valley on Tuesday. Rain will develop overnight in Montreal and persist all day Tuesday. Amounts will range from 20-30mm along the St. Lawrence Valley to as much as 60mm in the Laurentians and north of Quebec City. Environment Canada has posted heavy rainfall warnings for the region north of the St. Lawrence River. The rain will be accompanied by the occasional rumble of thunder as well as gusty winds. With the rain, temperatures will remain below normal with a low of 18C (65F) tonight but only up to 21C (70F) on Tuesday. The remainder of the week looks unsettled with slightly below normal temperatures and the ever present risk of showers or thunderstorms.

Feeling like September in Montreal

Despite high pressure trying to nudge into southern Quebec, it remains partly cloudy and cool today. Cold air aloft has generated cloud cover this afternoon in Montreal, as well as a few showers. The temperature is cool for early August, sitting at 22C (72F). Skies will clear out after sunset tonight with cool overnight lows in the low to middle teens (50 to 60F). On Friday we should finally break away from the stubborn low in northern Quebec and see more sun than clouds. Temperatures will warm up to 25C (77F). At this time the weekend looks nearly perfect with abundant sunshine and high temperatures from 25 to 28C (77-83F). Overnight lows will range form 12 to 14C (52-56F) under clear skies with just some patchy fog possible.  A strong fall-like low pressure system is forecast to develop along the southeast coast of the US and move northeast affecting Atlantic Canada. At this time is is expected to remain well east of our area. With the exception of this upcoming Sunday when we may hit 28C (83F), the early September feel to the weather will persist well into next week. More rain is forecast next week as a surge of moisture moves north from the Gulf of Mexico.

SEVERE WEATHER
Thunderstorms in southern Quebec on Wednesday afternoon developed north of Montreal and passed to our east. Large hail was reported along Highway 40 east of Repentigny as well as heavy rain. The bulk of the severe weather affected mainly the Townships and Beauce for the third day in a row.

Massive thunderstorms dropped tons of hail on Calgary late Tuesday afternoon. Widespread damage was reported.
(CBC News)

In western Canada fierce thunderstorms swept through southern Alberta late on Tuesday, August 4th. In a matter of minutes the storms dumped heavy rain and hail on Calgary, knocking out power to over 35,000 customers and producing flash floods. Numerous roads were impassable and the ground was covered in a thick blanket of hail. The hail pounded trees, cars and gardens causing widespread damage and stranding motorists. Strong winds toppled trees, power line and utility poles. Another round of severe weather hit Calgary on Wednesday causing more flooding.

Unsettled weather week ahead for Montreal

A Hydro Quebec crew restores power in St Georges in the Beauce region after strong thunderstorms Monday afternoon. (Twitter@hydroquebec)

As has been the rule most of this summer, the main area of thunderstorms developed north and then southeast of Montreal on Monday, missing the city. This resulted in a decent day for Montreal. The morning was cloudy and almost September-like, but the afternoon had sunshine and temperatures responded with a high near 26C (80F). Today will be very similar to Monday, with more showers and thunderstorms developing by afternoon but also a good amount of sunshine. High temperatures will range from 24 to 27C (75 to 80F) across the entire area. A stubborn upper-level low over Hudson Bay with a cool pool of air aloft continues to spin off these areas of energy across Quebec and New England. Any thunderstorm activity that does occur today has the potential for small hail and heavy rain. This weather will persist through Wednesday before skies clear out and temperatures cool down Thursday.

On Monday, strong storms developed across northern Vermont and moved into the Eastern Townships and Beauce region of Quebec. Heavy rain caused some minor flooding along with reports of hail. According to Hydro Quebec, power outages were numerous in the region, but most customers have been restored as of this morning.

EF-2 Tornado
Environment Canada has confirmed an EF-2 tornado struck Teviotdale, Ontario late Sunday. The 9pm storm was part of a large area of fierce thunderstorms that cut power to over 50,000 homes in Ontario. Major damage was reported along a 7 kilometre by 200 metre path. EF-2 tornadoes are capable of winds up to 177km/h. Elsewhere in the province wind damage was widespread, with many regions reporting gusts in excess of 100km/h with the thunderstorms.

Strong thunderstorms possible today for southern Quebec

Strong thunderstorms are possible today from Montreal south and east into the Townships, New York and Vermont. (AccuWeather)

A potent cold front will slide southeast across southern Quebec later this morning and this afternoon. The front has a history of generating strong to locally severe thunderstorms along it. On Sunday strong storms swept Michigan and southwest Ontario. Power was knocked out to thousands along with reports of damage including fallen trees and power lines. Hail and heavy rain were also observed. Isolated tornadoes also occurred from Iowa into extreme southwest Ontario. The biggest threat for severe weather across metro Montreal will occur from 11am onward towards sunset. Isolated strong storms will produce gusty winds, heavy rain and hail. A severe thunderstorm watch is in effect this morning for the border regions south and east of Montreal and may be extended later this morning.

A tree crushed this VW on Grace Street in Toronto Sunday afternoon. This was just one of numerous trees and power lines brought down across southwestern Ontario from strong thunderstorms. PHOTO: (Twitter @NEWSneil)

Early this morning scattered showers are occurring along a warm front in Montreal. It is a rather humid morning with current temperatures around 21C (70F) across the region. Highs today will range from 25 to 30C (77-86F) region wide, depending on how much sunshine you get before the cold front arrives. As the front clears the region later tonight, skies will become partly cloudy with lows in the middle teens. More unsettled weather is likely on Tuesday with showers and thunderstorms lingering. Temperatures will trend slightly cooler than normal through the middle part of the week.