Tag: tornado

Alberta

Severe Weather Envelopes the Southwestern Prairies Thursday; Reloads Friday

A potent upper-air pattern will create extreme instability across the Southwestern Prairies Thursday. A surface trough will slice through the summer air offering a trigger for explosive thunderstorm development in the unstable atmosphere.

Winds at the surface out of the southeast and upper-level winds from the southwest suggest a well-sheared warm sector. The strongest surface heating will remain just south of the border. In spite of that, ample moisture delivery, temperatures falling aloft, effective shear, and plenty of energy will provide a breeding grounding for severe thunderstorms Thursday.

Thunderstorms will develop across Southern Alberta and Northern Montana around 2 pm. Trans-versing northeastwards throughout the afternoon and evening, Initial storm develop may feature discrete cells and bowing segments; a threat for large hail, damaging winds, and an isolated tornado is possible. As progression into the evening continues, a powerful nocturnal complex of thunderstorms known as a Mesoscale Convective Complex (MCS), may develop. These convective weather systems are notorious producers of damaging winds, intense frequent lightning, large hail, and localized flooding in torrential downpours. Moreover, these systems are known to persist well into the pre-dawn hours.

click to navigate forecast map.

HAZARDS: 90-110km/h wind gusts, 2-5cm hail, torrential rainfall, frequent lightning, and an isolated tornado.

We will be monitoring the thunderstorms throughout Saskatchewan and Alberta attentively on Thursday. Be sure to closely monitor watches and warnings throughout the afternoon, evening and overnight. We will be issuing another forecast for severe thunderstorm risk in Saskatchewan, Friday. The risk depends greatly on the evolution of thunderstorms Thursday into pre-dawn Friday.

HEAVY RAINFALL CONTINUES WEST OF EDMONTON

Much of the focus is rightfully centered around substantial thunderstorm risk further south, but appreciable rainfall amounts along the Highway 16 & 40 corridor is worth mentioning. This region has already seen very-heavy rainfall over the last several days. Another 50-75mm is on tap between Hinton and Edmonton, through Friday.

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. 

Manitoba

Powerful Supercells for SE Saskatchewan Bring Tornado Risk and…


An associated warm front will set the stage for parameters conducive for strong Tornadoes today for isolated regions in SE Saskatchewan.

Residents in Southeastern Saskatchewan should be extra vigilant to the sky as the current risk leads to a threat for 1 or 2 strong Tornadoes (EF2+), large hail (nickel to ‘ping-pong’ size) and damaging winds (100-120km+).

As the cells form mainly just west of Weyburn, quick evolution and a track E to ENE as LP (low precipitative) supercells will be prevalent. These cells are representative of large hail (in this case, ‘ping-pong size), and a risk for a Tornado a little after their original formation as shear levels drop a slightly.

As the cells continue to track into Manitoba, the cells will become more of a ‘line’ just across the border into Virden, Melita and Brandon – winds up to 120km/h+ are the main threat and the Tornado threat will diminish rapidly.

Elsewhere, isolated severe cells over a large swath of Saskatchewan and Manitoba are possible.

Amongst the most interesting parameter (one among many) is the LCL (lifted condensation level: represents the lowest level in which condensation can occur). Generally, the strongest Tornadoes in history are between 300-600m. LCL levels, in this case, are somewhat conducive to Tornadoes of EF2 or stronger nature.

Remember, summer thunderstorm forecasts  – severe and/or non-severe – represent a plausible scenario based on extensive weather calculations, parameters and up-to-date atmospheric data. Nothing is for certain, but outlines a possible or likely scenario based on the aforementioned points.

Please stay tuned, as we at TCW are monitoring this situation attentively.

Drive safe and always be alert during hazardous conditions.

For hourly and live storm updates around the clock, follow us on Twitter.
https://twitter.com/TransCANWeather

Manitoba

Risk of Damaging Hail and Tornadoes in the Prairies

Severe thunderstorms possible today (June 14th, 2018) in Southeastern Saskatchewan and Southwestern Manitoba. Isolated severe thunderstorm risk continues across Southern Manitoba throughout the evening and overnight.

A disturbance is forecast to move into Saskatchewan today from Alberta. At the same time, a surface low will be moving northwards from the United States. HIGH levels of energy will build south of an associated warm front.

Although this warm front isn’t expected to make it far north of the border (keeping high amounts of energy stateside), moderate energy amounts, and an environment conductive to severe weather is expected. Including discrete cells and supercells capable of producing damaging wind gusts up to 100km/h, toonie to golf-ball sized hail, and a risk for 1 or more tornadoe(s). Damaging hail is currently what we are most concerned about.

Environment Canada (PASPC) has highlighted the risk for 3-5cm hail, 90-100km/h wind, and an isolated tornado in their “moderate” severe risk zone (highlighted in orange). Please note: these maps are still in the experimental stage.

We will be closely watching an area south of a line from Carlyle to Antler to Souris between 5pm-9pm. An isolated severe threat will continue in southern Manitoba through the evening and overnight, as cells become more linear (MCC – Mesoscale Convective Complex) – increasing a chance for damaging winds, torrential rainfall, hail and frequent lightning.

– TCW

Ontario

Severe Thunderstorm Risk Builds in Southern Ontario

Showers and a risk of severe thunderstorms for Southern Ontario. Heavy rainfall from East of Lake Superior to the Quebec border Wednesday (June 13th, 2018).

A strengthening low pressure system will track East of Lake Superior through the Nickel Belt Wednesday, bringing a risk for heavy rainfall for Northern Ontario and a risk of severe thunderstorms in Southern Ontario. 

WHAT’S EXPECTED 

A swath near the low track, from East of Lake Superior to the Quebec border will likely see rainfall amounts of 25-50mm between Wednesday morning to evening. 

Further south, across Southern Ontario – there will be 2 rounds of precipitation. The first, along a warm front as it edges north into Southwestern Ontario, bringing scattered showers Tuesday evening through Wednesday morning. Once the warm front moves north, there will be a clearing allowing for sunny breaks and energy to build ahead of a cold front acting as a trigger for thunderstorms Wednesday afternoon. Some of these thunderstorms may be severe with damaging winds as the primary threat.

A window for a low tornado threat is possible from mid to late afternoon in our red highlighted area. The greatest threat will be along a “triple-point” – between 1pm and 6pm. This region may expand to include municipalities near the Lake Ontario shoreline. 

Environment Canada (OSPC) is calling for a “moderate” risk of severe thunderstorms. The primary threats according to their risk map is damaging winds up to 100km/h. Please note: these maps are still in the experimental stage. 

STRONG WINDS

After the passage of the cold front the low will continue to deepen as it moves into Quebec. Strong wrap around winds will develop Wednesday evening and overnight. Gusts between 60-80km/h are expected across much of Southwestern, and South-central Ontario. Localized gusts to 90km/h are possible in higher elevation South of Georgian Bay, as well as, near the lakeshore.