Author: Troy Boone

Quebec

Severe Thunderstorm Risk Pushes East into Quebec

A strong cold front will act as a trigger for isolated severe thunderstorms across the Eastern Townships and Southeastern Quebec Wednesday. Damaging winds, torrential rainfall giving 25-50mm of rain in a short duration, frequent lightning and isolated supercell(s) are risk factors with these storms.

Thunderstorms may track into Northern New Brunswick bringing heavy rainfall and lightning as they begin to weaken and become elevated. 

TECHNICAL ANALYSIS:

A developing area of low-pressure will track out of Northeastern Ontario into Quebec Wednesday, deepening rapidly. An area of height-falls & falling atmospheric pressure will overspread the warm sector, ahead of a seasonably sharp cold front. Temperatures will rise into the mid-20s with dew-points nearing 20c. Pockets of 1500J/kg of CAPE should develop across the warm sector. Largely unfavourable lapse rates will be compensated by a strong tendency for ascent. 65 knot, 500mb flow will overspread the Eastern Townships & Southeastern Quebec – ahead of an amplified, positively tilted trough. A modest low-level jet should be sufficient for moisture transport across the warm sector, and a damaging wind threat. Speed-shear and wind shear will be sufficient enough to sustain long-lived updrafts – well-tilted updrafts capable of rotating. A threat for stronger bowing-linear segments or super-cells exists between 1-5pm. Additional risks, include torrential downpours, frequent lightning and hail in the stronger updrafts.

Timing of the cold front and pre-frontal clearing will be important determining factors considering how severe thunderstorms will be. 

Ontario

Another Round of Severe Weather Targets Southern Ontario &…

Monday will be a pleasant seasonal day, dominated by high pressure and brilliant sunshine – across Southern Ontario & Quebec.

Wet, humid and stormy conditions start the week, with a risk of thunderstorms. Find out when and where.

SYNOPSIS:

Cloud, spotty showers, steady rainfall and humidity will make a return to Southwestern Ontario as early as tonight, with a warm front pushing northwards. Overspreading, the rest of Southern Ontario and Extreme Southern Quebec by Tuesday Morning.

Concurrently, an area of low pressure will strengthen along the Manitoba/Ontario border as it tracks towards Hudson Bay. 15-30mm of rainfall is expected in Northwestern Ontario. With wet snow mixing in across far Northern sections. 

2 WAVES OF PRECIPITATION

The first wave of precipitation will arrive overnight tonight into Tuesday morning across Southern Ontario, moving into Quebec by the morning – ending early afternoon. Some embedded heavy-downpours is expended in a swath from the shores of Lake Erie to Niagara. Elsewhere, expect light to moderate rainfall and predominantly cloudy, warm and humid conditions. Dry slot arrives in the late morning to afternoon.

We will be watching Southwestern Ontario closely Tuesday, as any clearing could further destabilize the atmosphere increasing the risk of evening thunderstorms ahead of the cold front.

SECOND WAVE; RISK OF ISOLATED SEVERE THUNDERSTORMS

Associated with a sharp cold front – along a developing strong area of low-pressure forecast to deepen as it tracks through Northeastern Ontario and Quebec.

SOUTHERN ONTARIO

Thunderstorms will develop ahead of a cold front Tuesday night, persisting into Wednesday morning from East of Georgian Bay through Southwest Ontario. Isolated severe storms are possible. Bringing isolated strong wind gusts and heavy downpours. 

SOUTHEASTERN QUEBEC

A risk of isolated severe thunderstorms develops for Extreme Eastern Ontario and Southeastern Quebec late Wednesday morning or early afternoon, ahead of a sharp cold front. The primary risk will be damaging winds and heavy downpours. Isolated supercell(s) cannot be ruled out in Southeastern Quebec, but the risk will largely depend on timing & clearing.

GUSTY WINDS

Gusty southwesterly winds of 40-60km/h will overspread the risk area Tuesday. Becoming northwesterly through Wednesday. The strongest wind gusts of 60-70km/h will remain draped across Central Quebec and Nova Scotia.

Ontario

Potent System: Severe Thunderstorms & Pattern Change for Ontario…

[UPDATED] A strong fall-like system will track across Ontario and Quebec Friday, bringing a risk of severe thunderstorms. Heavy rainfall, strong winds and a pattern change is expected. Find out where.

Through the day Thursday, an area of low-pressure will deepen as it tracks from the Midwest into Northeastern Ontario, Friday morning. The low will mature as it tracks into Quebec by Friday afternoon.

A warm front, associated with the seasonably-deep low will push north across Ontario and Quebec Thursday morning into Friday. Concurrently, temperatures will soar into the high-20s Friday afternoon across Southern Ontario and Southern Quebec (near the border). Increasing dew-points will lead to muggy conditions feeling into the mid-30s.

Instability, very-strong upper-level winds, wind-shear, and marginal energy will lead to severe thunderstorms Friday. Ahead of a vigorous cold front, and strong upper-level trough where heights will be falling.

RISK & COVERAGE

The greatest risk for severe thunderstorms in Ontario will stretch from Central Ontario to Eastern Ontario. Coverage will be more isolated in Ontario than Quebec. These thunderstorms will be capable of producing strong wind gusts. Upscale growth into a squall-line bringing straight-line winds, heavy downpours and frequent lightning is possible.

In Quebec, atmospheric energy & cooler temperatures will be less favorable than Southern Ontario, but better forcing, shear, and instability will lead to isolated-severe thunderstorms. Risks include damaging winds, frequent lightning and heavy downpours. This will include the risk of supercells. The strongest risk will largely affect rural, unpopulated municipalities.

WIND & HEAVY RAINFALL

Regardless of thunderstorms, synoptic winds will be strong across Southern Ontario and Southern Quebec with this fall-like system. Widespread gusts between 50-80km is expected across a large swath of Ontario and Quebec, preceding the cold front and after its passage.

UPDATE: latest model guidance is suggesting that localized wind gusts of 90-100km will impact Ontario and much of Quebec.

30-50mm of rainfall is expected along a swath East of Lake Superior through Northeastern Ontario.

PATTERN CHANGE INTO FALL

The passage of the cold front will usher is much cooler and drier conditions by Friday night. Temperatures will struggle to get into the mid-teens by the weekend. A hard freeze is looking probable across Northern Quebec and Northern Ontario.

Alberta

Snowflakes Fly in Alberta Wednesday Morning



Environment Canada issues Snowfall Warnings and Special Weather Statements across Central Alberta Wednesday. 

A cold front decended on the province Tuesday into Wednesday morning, sending temperatures near or below the freezing mark.


An area stretching from Slave Lake to Jasper included in Environment Canada’s snowfall warning, which may see 10-15cm of snow. 

Edmonton was awaken to temperatures near the freezing mark. Barrhead saw temperatures drop below-zero with accumulating snow.

 Several wet centimetres can be expected across the region, draped in Special Weather Statements.

https://twitter.com/_shewanders/status/1039881424558481408?s=21
As you can see clearly, there are mixed feelings about the early snowfall shared by this social media user.

Edmonton will not escape the early taste of winter, with a couple wet centimetres possible. Even Calgary, could experience a few wet flakes Wednesday.   



Alberta

Environment Canada Issues Frost Advisories in the Prairies

Environment Canada has issued a frost advisory for much of Southern Saskatchewan and Central Alberta. 

Damage to sensitive crops is possible tonight.

SASKATCHEWAN:

Frost may damage some crops in frost-prone areas.

A ridge of high pressure building over the prairies will bring clear skies and cold overnight lows to Saskatchewan Tuesday night. Overnight lows are expected to be between 0 and -3 Celsius by Wednesday morning.

Special Weather Statement for Saskatchewan

ALBERTA:

Frost may damage some crops in frost-prone areas.

Overnight lows are expected to reach near the freezing mark. Frost is possible overnight.

Take preventative measures to protect frost-sensitive plants and trees.

Frost advisories are issued when temperatures are expected to reach the freezing mark during the growing season, leading to potential damage and destruction to plants and crops.

Special Weather Statement for Alberta

Newfoundland and Labrador

Powerful Storm to Develop Across Newfoundland & Labrador Tuesday

A seasonably-deep low pressure system will develop rapidly Tuesday; impacting Newfoundland & Labrador.

The central pressure is forecast to deepen an incredible 22mb in 24 hours, almost reaching the criteria to be considered a “weatherbomb”.
#NLwx

Far, and largely unpopulated, Northeastern Labrador will see snow mix-in. Accumulating snow is possible in Greenland.

Expect pounding surf of 3-5m and beach erosion in Labrador. As well as, heavy rainfall and strong winds. Strongest winds to 90km/h will remain well off the coast.

Projected Wave Heights

NEWFOUNDLAND:

Western sections will see locally-heavy rainfall with this system. The biggest weather story is focused on a sudden change in weather pattern.

Warm & humid conditions dominating the Province will end, at least temporarily, with the passage of a cold front.

A cooler much-drier airmass will move across the province West to East throughout Tuesday.

 

Ontario

Wet & Stormy Tuesday Across the Lower Great Lakes

Heavy thunderstorms expected Tuesday (August 21st, 2018) across Southern Ontario.

Rain-showers or thunderstorms are expected to begin moving into deep Southwestern Ontario overnight Monday into Tuesday. Convection will spread throughout Southern Ontario throughout the morning and afternoon as a maturing-low approaches from the US. Another round is possible by the mid-evening along the shores of Lake Huron.

BRIEF CLEARING? & HEAVY RAINFALL

There may be some brief clearing stretching from the Golden Horseshoe into Southwestern Ontario. This would add more energy and instability, allowing for some isolated severe thunderstorms capable of very-strong winds and short-lived rotation.

Much of the day however, is expected to be dominated by cloud, showers and passing heavy thunderstorms – perhaps several rounds. This could lead to locally significant rainfall-totals. With the threat of localized flooding. Widespread amounts between 30-50mm is expected.

BENEFICIAL RAIN:

East of Georgian Bay stretching into East of Superior will see a beneficial, soaking rainfall from this system. Which will help alleviate forest fire concerns, plaguing the region this summer.

WIND:

This will be an early fall-like system for the Great Lakes. As we move deeper into August we are beginning to enter a transitional period, where low-pressure systems produce synoptic rain and wind over a larger area. Widespread winds gusting between 50-70km/h are expected between Tuesday late-afternoon, and through the evening.

No need for “the end of sunmer blues” quite yet, temperatures by this weekend will be near 30c feeling closer to 40c with the humdity factored in.

Manitoba

One Man Deceased After a Tornado Strikes the Rural…

 

https://twitter.com/justinhobson85/status/1025576138192515072?s=21

Severe thunderstorms, including a tornadic supercell thunderstorm tracked across rural Western Manitoba, Friday.

Current indications suggest the tornado was on the ground for 30-45 minutes. Social media users also reported golf-ball to tennis-ball-sized hail, creating additional property damage – unrelated to the tornado. 

Alonsa, Manitoba was hit particularly hard. Photos and videos circulating across social media have shown significant structural damage to homes, trees and property. The RCMP has confirmed the death of one Alonsa resident, a 77-year-old man found outside his badly damaged home. 

The tornado tracking through Alonsa around 9pm CDT. Bluff Creek and Margaret Bruce Beach were hit particularly hard. 

This photo posted to twitter shows a flipped camper in Margaret Bruce Beach. Located near Silver Ridge. 

 

Alberta

Tornado & Damaging Hail Threatens the Edmonton Region

A potent severe weather setup is expected today (July 20th 2018) in the Western Prairies. 

Thunderstorm risk map for today. The highest severe threat is highlighted in red – which includes Edmonton in a risk for tennis-ball sized hail and an isolated tornado. 

Environment Canada Discussion (PASPC):

ALBERTA 

A low pressure system developing in Alberta with an associated trough swinging through west-central Saskatchewan in the afternoon will trigger scattered severe thunderstorms. The main threat with these storms will be large hail. In the northwest section, there is a potential for supercells to develop with the potential of producing a tornado. The severe potential will last into the evening but thunderstorms are expected to persist into the overnight.

SASKATCHEWAN 

A low pressure system developing in Alberta with an associated trough swinging through west-central Saskatchewan in the afternoon will trigger scattered severe thunderstorms. The main threat with these storms will be large hail. In the northwest section, there is a potential for supercells to develop with the potential of producing a tornado. The severe potential will last into the evening but thunderstorms are expected to persist into the overnight.

Environment Canada’s Thunderstorm Outlook for today July, 20th 2018. Highlighting an extreme risk for severe thunderstorms in the Capital Region.

TECHNICAL DISCUSSION

A low pressure system will form south of Edmonton today with an associated cold front extending southward along the northern foothills and warm front through east-central Alberta and into Saskatchewan. Severe thunderstorms will trigger along the cold front early in the afternoon. They will likely be isolated in nature at first, before becoming a severe line of thunderstorms. The warm front will track through the area in the morning followed by a trough in the afternoon. Severe thunderstorms are expected to trigger along the trough in the afternoon. There is the potential for the right conditions to align near and to the east of Edmonton for a tornado to form, with the potential extending into west-central Saskatchewan, albeit, less likely than the risk in Alberta. MLCAPE values are between 1500 to 2200 J/kg with 0-6 km shear values around 30 kt with values up to 40 kt in and around the Capital region in Alberta. RDPS prog tephis are indicating idealized veering hodographs, conducive to tornado development, however, tornado formation in this area will be highly dependent on a few factors: There is the potential that the low level shear will be too much for the marginal CAPE in some areas, essentially shearing the storms apart. As well, on the Saskatchewan side, LCLs are progged to be around 1500 – 2000 m, which is a little high for tornado development, whereas, on the Alberta side, LCLs are progged to be 1000 m, which is more favourable for the formation of tornadoes. In addition, models are indicating the formation of a dryline that will bulge out into the southwestern corner of the Lloydminster region which may also be an area to watch for a tornado to develop in the later afternoon hours.

*Please note this maps and discussions are currently experimental and are not currently operational on Environment Canada’s website. 

Please closely monitor Environment Canada alerts today. Take any warnings seriously and seek shelter immediately. 

We will be monitoring the situation attentively. 

British Columbia

British Columbia Prepares for the Wildfire Season

As the sun sets a helicopter prepares to dump water on a blaze near Williams Lake, BC Wednesday, July 12, 2017. Jason Payne – Vancouver Sun

After a devastating forest fire season in 2017, tougher penalties in an effort to reduce wildfire risk, have been made law this year – ahead of the dry season. Read more about new failure to comply measures put into law.

It is common for summer temperatures to peak between 30-35 degrees Celsius during the summer months in the Southern Interior. Coupled with long stretches of dry, sunny weather, and low relative humidity. 

Fire Rating July 17th, 2018. Natural Resources Canada.

Hot and dry weather will be the story through the beginning of this week with the Southern Interior reaching the low 30s. In Kamloops, an air quality statement, together with a heat warning have been issued. A respite from the heat is expected mid-week with the arrival of upper-level trough. 

As early as Thursday & Friday, cooler temperatures will spread across the Interior. A chance of rain and cloudier conditions will be welcomed in some communities – but others who see lightning could see new fires.

Current forest fires burning in British Columbia. 

On Vancouver Island, sunny and pleasant conditions are expected to persistent for many days. Coupled with low-humidity, the Victoria vicinity will see rising fire ratings. 

Unfortunately, high-pressure will return to British Columbia next week. Temperatures will once again soar into the high 20s or 30s. The dry season may persist well into August this year.