Strong storms bring relief from heatwave - produce power outages

Lightning illuminates the night sky over Ile Perrot. Strong thunderstorms Tuesday afternoon and evening brought an end to our record-breaking heatwave. (ValleyWeather Photo)

Our remarkable seven day heatwave is over in Montreal. We manged six consecutive days of temperatures over 32C (90F) at Trudeau Airport. This was an extremely rare event for the city, and a first for the month of June. The heatwave ended Tuesday evening as strong thunderstorms developed well in advance of a cold front. Before that however, we managed to set yet another record high, the third in a week. The mercury soared to 33.1C (91.5F) by 1pm, surpassing the old record of 32.7C (91F) set in 1989. On Monday, the high was 34.8C (95F), also a record, the previous was 32.2C (90F) set in 1957. That mark of 34.8C was just two tenths of a degree below the all-time June record of 35C (95F) set in 1964. Montreal averages 9 days a year of temperatures in excess of 30C (86F), Tuesday was our 12th day already in 2020.

STRONG STORMS
The end of the heatwave did not come quietly, as strong thunderstorms swept across the city from south to north. The first batch affected areas off-island to the west around 1pm, with heavy rain and strong winds. The second pulse of storms was much stronger, sweeping across the Monteregie, Island of Montreal, Laval and the North Shore, knocking out power to over 70,000 Hydro-Quebec customers, and uprooting several trees. A wind gust to 96 km/h (59 mph) was recorded at Trudeau Airport at 6:50pm. The number of outages in the province is down to 229 Wednesday morning, affecting 21,000 customers.

Much need rainfall accompanied the storms, with 26.7mm falling here on Ile Perrot. Less fell at Trudeau Airport, with 13.6mm recorded. While the rainfall was greatly appreciated, conditions remain very dry in many parts of the province. At this time, numerous water restrictions remain in effect, check with your municipality for exact details. The normal rainfall for May is 81.2mm and June 87mm. To date we have only received 27.8mm at Trudeau Airport for June. May was dry as well, with only 34.2mm of rain falling along with a trace of snow.

Cooler, windy weather is expected for Wednesday, with a high of 25C (77F) and gusty southwest winds to 50km/h. Enjoy the relief over the next few days, hot and humid weather is expected to return by early next week, with perhaps another significant heatwave on tap to start July.

Quebec heatwave to persist through Tuesday

The first day of summer in Montreal was a hot one. Trudeau Airport reached a record breaking 33.4C (92F) as the heatwave stretched into a 4th day. No relief is in sight until Wednesday at the earliest.

Some of the warmest temperatures in North America are occurring right here across southern and eastern Quebec into New Brunswick. Over three dozen record highs occurred on Friday, followed by more record heat on Saturday. Montreal reached 33.9C (93F) Saturday afternoon, surpassing the previous high of 32.7C set in 2012. It was the fifth 32C (90F) day already this year and the fourth day of our current heatwave. The previous highs in Montreal have fallen just below the records, reaching 33.5C (92F) Thursday, and 32.9C (91F) Friday. That makes this an official heatwave, the first of the summer. Arguably, many locations had a heatwave back in late May, but Montreal fell short by one tenth of a degree!

The hot weather is expected to continue through at least Tuesday as strong high pressure remains anchored over the region. The air mass has become increasingly humid and stale to say the least, and a smog warning has been added to the heat advisory already in effect. Forest fire smoke is adding to the poor air quality. We need a soaking rain to scrub the atmosphere and save our lawns. A watering ban remains in effect in many southern Quebec municipalities, including here on Ile Perrot. Sadly many of my neigbours have lush green lawns and are ignoring the ban.

WATERING BAN
Any rain that has occurred has been spotty at best. A few scattered showers and thunderstorms developed over the Adirondacks on Friday and Saturday, drifting into extreme southern Quebec. The same is expected today and Monday, with perhaps a cell or two reaching metro Montreal. The real threat for widespread thunderstorms, some strong, will occur by Wednesday afternoon, as a cold front brings some relief from the heat. Until then, expect daytime highs in the low 30s and overnight lows in the low 20s. Humidex values will reach nearly 40C (104F) during the daylight hours.

SUMMER SOLSTICE
Spring came to an end on Saturday, with the summer solstice occurring at 5:43PM EDT. The spring season in Montreal and across many parts of North America was bizarre to say the least as winter and summer waged an epic battle. Montreal's spring featured record heat, record cold, severe thunderstorms, windstorms, May snow, widespread drought conditions and early forest fires all wrapped into three months. I can't wait to see what summer 2020 brings.

Heatwave to persist into early next week

Hot weather predicted for the balance of the week, may challenge some southern Quebec temperature records. The heatwave is forecast to persist through the weekend. The forecast high in Montreal of 34C (94F) on Thursday would break the record of 33.9C set in 1994. (AccuWeather.com)

Strong high pressure anchored over southern Quebec, will provide the entire region with a prolonged stretch of very warm and increasingly humid weather. An upper level low is spinning off the Carolina coast, forcing the high pressure to remain nearly stationary over the region. This is a similar set up to earlier late May when Montreal reached 36.6C (98F).

At the moment, we are forecasting daytime highs in excess of 30C from Wednesday through at least Sunday. As the upper level low begins to lift northward along the eastern seaboard, the St. Lawrence Valley will begin to see increasing dewpoints and humidity. The weather will become oppressive by Friday into the upcoming weekend. There is a risk of isolated showers and thunderstorms both Saturday and Sunday, but they will be widely scattered at best.

Conditions remain very dry across many parts of southern Quebec. SOPFEU is fighting a large forest fire in the Saquenay region that remains out of control, having burned over 3400 hectares.

Conditions remain very dry across souther Quebec. According to SOPFEU, the Montreal region is under extreme fire conditions. After only receiving one third the normal rainfall in May, the city has recorded just 14.2mm in June to date. The normal for the month is 87mm. The dry, hot conditions have increased the fire danger across Quebec. Fire bans are being issued once again for several regions of the province, and outdoor burning of any kind is strongly discouraged. Several municipalities including mine here in Notre-Dame-de-L'Ile Perrot, are banning any outdoor water use until further notice. This includes watering the lawn, washing your car and filling pools.

No appreciable rain is in the forecast at this time until perhaps early next week. The rounds of thunderstorms that occurred last week, largely missed the metro Montreal region.