Monday, May 25, 2015

From frost to heat & humidity

In less than 36 hours many locations in southern Quebec and eastern Ontario went from sub-zero overnight lows with frost to high temperatures near 30C on Sunday. Montreal was no different after an overnight low of 2C (36F) early Saturday morning, we managed a sultry high of 27C (81F) Sunday afternoon.

The forecast for the week looks very summery with high pressure moving off the east coast of the US and pumping warm and humid air northward into New England, Quebec and Ontario. A strong warm front will lift northward across the entire region today with scattered showers and thunderstorms. Cloud cover will keep temperatures in check with perhaps 22C (72F) for a high. I don't expect severe weather but any of the storms that do develop today have the potential to produce very heavy rain. Overnight it will remain mild with lows near 20C (68F). Tuesday promises to be quite warm and humid with high temperatures at or even above 30C (86F) in eastern Ontario and southern Quebec. I expect sunshine on Tuesday. The balance of the week looks partly to mostly cloudy and very warm and humid with a chance of showers and thunderstorms each afternoon. Gusty south winds from 20 to 50km/h most days will continue to pump humid air north from the southern US.

The aftermath of strong thunderstorms in Cache Creek, BC. (CBC News)
B.C. Thunderstorms
Meanwhile in the community of Cache Creek, B.C. severe thunderstorms with hail and heavy rain produced major flash flooding early Saturday. Numerous homes were destroyed as a wall of water and mud swept the town north of Merritt. A state of emergency has been declared as the cleanup begins. Many families were trapped in their homes and scores are homeless today.

Unprecedented flooding is occurring in San Marcos, Texas. (City of San Marcos Photo)
TEXAS FLOODING
Record flooding continues this morning across portions of Texas and Oklahoma. Water levels have reached heights never seen before in many communities along the border between the two states. Major flooding has also been rolling down the Blanco and San Marcos Rivers between San Antonio and Austin, Texas. The flood waters have forced massive evacuations and resulted in a heavy loss of property and at least three fatalities. Strong thunderstorms have drenched the region with more rain in the month of May than in the last year combined. Over 20 inches of rain has fallen across north Texas this month alone.

Friday, May 22, 2015

Widespread frost tonight - weekend update

Widespread frost and freezing temperatures are forecast tonight across southern Quebec, eastern Ontario and New England. A cold front is producing sprinkles and clouds today with dropping temperatures. The high in Montreal will remain around 10C (50F), well below the normal of 21C (70F). Unseasonably cold air will settle into the region tonight with lows of plus 2C to -3C (36F to 27F). The coldest readings will be away from Montreal and any bodies of water. Needless to say if you have planted anything, you should cover them up and take precautions to protect your flowers etc. Frost and freeze advisories are in effect across our entire region with the exception of metro Montreal and Grand Island County, Vermont on Lake Champlain.

The good news is that the cold air will be short lived. A much warmer and sunny weekend is forecast with highs of 18C (65F) Saturday and 24C (76F) Sunday. Next week is looking very summer like with a warm and humid air mass enveloping the northeast and southern Quebec and Ontario. Highs will be in the upper 20's with a risk of showers and thunderstorms each day.

Major flooding is occurring in Texas as heavy rain has pushed accumulation to nearly 20 inches in May. The photo above was taken on Thursday in Fort Worth, Texas, no injuries were reported. (CBS Dallas)

Southern US Flooding
The warm and humid air expected in Montreal next week will be streaming northeast from the US Gulf Coast. Much of Texas, Oklahoma, Louisiana and Arkansas is reporting copious amounts of rainfall for May. Some areas are approaching 20 inches of rain for the month. This region, especially Texas, had been in a major drought throughout 2014. Dallas/Forth Worth recorded only 21.32 inches of rain in all of 2014. So far in 2015 they already have had 21.54 inches with much more forest this weekend. Flash flood watches remain in effect.

Wednesday, May 20, 2015

Possible tornado in Quebec - colder weather arrives

A spectacular photo of strong thunderstorms near Drummondville taken by the Quebec Vortex team on Tuesday afternoon. (Twitter@QuebecVortex)
There is definitely a change in the air this morning in Montreal. After a muggy high near 27C (81F) on Tuesday, the temperature is a cold and dry 7C (45F) here on L'Ile Perrot this morning. Adding to the nip in the air is a 40km/h northwest wind and persistent clouds. Conditions will improve today with clearing skies and lighter winds, but it will remain quite chilly with a forecast high of only 16C (61F). Expect clear skies tonight with a cold low of only 4C (39F), as well as a chance of frost in areas away from the city. Sunshine on Thursday and warmer with a high of 21C (70F) but more cold air is forecast to arrive Friday with a high of only 12C (54F). There is an even better chance of frost by early Saturday morning. An advisory may be needed.

The unseasonably cold air arrived behind a potent cold front on Tuesday. That front generated a line of strong to severe thunderstorms Tuesday afternoon from just east of Montreal into the Beauce and Townships. There were numerous reports of heavy rainfall, wind damage and hail as well as a confirmed tornado on the ground near Ste-Majorique south of Drummondville. Environment Canada will be investigating the damage today. The tornado prompted an afternoon of tornado warnings across the Beauce as the cells raced east towards the Maine border.

A dusting of snow occurred in Val D'or on Tuesday. (Meteo Media)
While the summer like weather was occurring here in the south, cold air pouring into central Quebec produced snow in Val D'or and Rouyn-Noranda last evening. The May snow was accompanied by gusty winds and temperatures below freezing.

Tuesday, May 19, 2015

More thunderstorms in Montreal before cool down

Thunderstorms produced flooding in portions of north end Montreal on Monday night. (Twitter@CJAD800)
It was a very warm and humid holiday Monday across southern Quebec with temperatures soaring to around 30C. I recorded 32.4C (90F) here On L'Ile Perrot, while Trudeau Airport reach 29.3C (85F), and St. Anicet hit 31.8C (89F). Strong thunderstorms fired up late in the afternoon over Eastern Ontario and the upper Ottawa Valley. Widespread watches and warnings were posted including a tornado warning for portions of eastern Ontario. Some rotation was observed in several of the storms including one that ripped trees out of the ground near Maniwaki, Quebec. As the storms pressed into southern Quebec small hail, very heavy rain and lots of lightning was observed. I recorded 6.6mm of rain here on L'Ile Perrot, around 0.25" in one of the storms late last evening. The strongest of the thunderstorms missed Montreal moving north and southeast of the city. However the ones that did occur were enough to drop 10mm of rain at the airport and as much as 30-35mm downtown in less than 1 hour causing some flooding.

Strong thunderstorms today
Today a sharp cold front will bring an end to this most recent warm spell as it moves across the St. Lawrence Valley later this afternoon. In advance of the front, gusty southwest winds will reach 60km/h in Montreal with a warm, muggy high of 25C (77F). Thunderstorms will develop by 1pm in southern Quebec as well as New York and Vermont and move northeast across the region. Some of the storms may produce small hail and strong winds up to 100km/h. The weather should clear late tonight or early Wednesday followed by dry but much colder weather for the balance of the week. High temperatures will only be around 15C (59F), with lows of 5C (41F). We may even see a little frost by Friday night in areas away from the city.

Monday, May 18, 2015

Wild spring weather contiues

Strong winds, rain and snow have made for a miserable holiday weekend in Manitoba. (CTV NEWS Manitoba)
May is often one of the most active weather months of the year as what is left of the winter cold in the Northern Hemisphere battles it out with the advancing warm and humid weather from the deep south. This weekend is a perfect example of that battle and the weather is distributes over North America as the atmosphere tries to balance itself. While southern Quebec is enjoying a peaceful, sun filled long holiday weekend with warm highs over 27C (80F) other portions of the country are not so lucky with wind, frost and even snow.

A strong low pressure area has been splitting the country in half as it moves from Colorado towards James Bay. To the west strong winds and heavy rain and wet snow have been reported from eastern Saskatchewan into northwest Ontario. Winnipeg is reporting snow this morning and a temperature of -1C (30F). Widespread frost was reported in Saskatchewan. Winds have been very strong across Manitoba, in excess of 80km/h with numerous reports of trees and power lines down. The same storm has a cold front trailing from it that will eventually cut through Montreal and the St. Lawrence Valley over the next 36 hours. That front produced lots of severe weather from Texas to the Dakotas on Saturday and again Sunday. Numerous tornadoes and large hail were reported with widespread damage. More strong thunderstorms  are forecast from the Great Lakes to the Midwest today.

A spectacular shot of a tornado near Elmer, Oklahoma on Saturday. Storm chasers caught the storm as it came dangerously close to a field of cows. No injuries were reported despite major damage in Oklahoma. (TVN Weather.com)
THUNDERSTORMS & COOLER
Montreal will remain between the Colorado low and a cool marine air mass just to our east on this Victoria Day Monday. We can expect a sunny and warm day with temperatures as warm as 30C (86F) in the southwest St. Lawrence Valley. Highs will be much cooler as you head east and southeast. Tonight the first of two cold fronts will produce showers and thunderstorms with a mild, humid low around 18C (65F). On Tuesday more showers and thunderstorms are forecast as a second cold front moves across Ontario and Quebec. The high Tuesday will be 24C (76F). The balance of the week will see clearing skies but much cooler with daytime highs below normal, only near 17C (63F). Temperatures will begin to warm once again by next weekend.

Thursday, May 14, 2015

A mixed bag of weather for Victoria Day weekend

Gusty thunderstorms on Tuesday produced localized heavy rain (10-20mm) and even small hail as they swept across southern Quebec around 1pm. Winds gusted over 75km/h in Montreal. This storm was moving through St.Laurent (ValeyWX Photo)
After a windy and chilly Wednesday that saw below normal high temperatures of only 15 to 17C (59 to 63F) in southern Quebec, we can expect a much warmer Thursday. High pressure will dominate the weather in southern Quebec through late Friday. It was a chilly start to the day this morning with lows down to 3.8C (38F) here on L'Ile Perrot. A frost advisory was in effect for the St. Lawrence Valley of New York, as well as portions of the Adirondacks, Green Mountains and also eastern Ontario, but there was no frost here at my home on L'Ile Perrot.

The upcoming Victoria Day long weekend is looking just ok. A warm front will produce some showers late Friday into Saturday. Most of Saturday will turn out dry but with plenty of cloud cover. By Sunday warmer and dryer air will be in place. High temperatures will range from 19 to 23C  (66 to 73F) through the remainder of the week. By Sunday we may nudge the temperature up to 24 or 25C (76 to 77F). At this time holiday Monday looks decent, but a rather vigorous cold front will produce showers and perhaps a thunderstorm by late in the day and into the overnight period.

Sunday, May 10, 2015

Thunderstorms, snowstorms & tropical storms

Happy Mother's Day to all the mom's out there!


Thunderstorms develop over L'Ile Perrot on Saturday, May 9, in the first warm and humid air of the season. (ValleyWX Photo)
We have a very active weather day across North America this Sunday as a strong spring storm moves across the central plains of the US. To the east, warm and humid air is firing up thunderstorms from Texas to the Great Lakes, Ontario and southern Quebec. A dangerous outbreak of severe weather with tornadoes is occurring from Texas into parts of Iowa today. Meanwhile to the west, heavy wet snow and strong winds with blizzard conditions are affecting the Dakotas. Travel is not advised in western South Dakota this morning.

Montreal remains on the northern edge of the warm and humid air. We managed to reach 28C (83F) on Saturday before scattered thunderstorms swept the region. As is the fickle nature of thunderstorms, I measured only 0.4mm of rain Saturday on L'Ile Perrot, while Trudeau Airport had 9.8mm. Some areas of the city and Laval has even more as the storms were much stronger in those locations. More storms can be expected today as a frontal system sags south into southern Quebec. Today will be the last really warm day for a week or so as we hit 25C (77F). Cooler air and rain will move in overnight with a raw, chilly and rainy Monday expected with highs only near 10C (50F). On Tuesday more showers and thunderstorms are forecast along a warm front with a high of 23C (73F). Things should clear out by Wednesday.

MAY? A South Dakota DOT camera shows the heavy snow and strong winds over the western Dakotas this morning. Travel is not advised in heavy snow and 50mph winds.
The warmth this week was very sudden and confined mostly to eastern Ontario and southern Quebec as we had some of the warmest temperatures in Canada. On Friday, Montreal recorded a record high of  28.8C (the previous record was 28.7 in 2013), Sherbrooke 28.4C (27.2 in 2007), and St Anicet a scorching 31.2C (29.8 in 2013).

As if all this weather was not enough, an early season tropical storm developed off the South Carolina coast this week and moved into Myrtle Beach early this morning. Tropical storm Ana has 60mph winds as well as 2-4 inches of rainfall to the east of her track. Heavy surf is pounding the North and South Carolina coast this morning as the storm slowly weakens and drifts inland today.