Tag: coldfront

Ontario

Thunderstorms Threaten Damaging Winds in Southern Ontario

A sudden surge of warm, summer-like air will herald in the risk of thunderstorms across the Lower Great Lakes. These thunderstorms may turn severe; capable of producing damaging winds & hail across portions of Southern Ontario. 

SURGING TEMPERATURES, THUNDERSTORMS & RAIN

An area of low-pressure will transverse through the Midwestern United States towards Ontario, throughout the day Sunday. Ahead of the system, temperatures will surge into the mid-20s and humidity readings into the low-30s. Near the Lake-shore, cooler conditions are expected.

Showers are expected before midnight tonight, lasting into the pre-dawn hours. Persistent rain-showers and embedded thunderstorms are expected for Central Ontario – mainly East of Georgian Bay. Sunny breaks are anticipated through the morning hours, allowing for some instability to build before the arrival of a cold front.

A soaking rainfall and single-digit temperatures North of the warm front. Heavy thunderstorms ahead & along a cold front in the South.

At this point, it appears the setup will feature two potential waves of thunderstorms. The primary wave will consist of a complex of heavy rain showers with embedded thunderstorms impacting Southern Ontario between 4-10 pm. Initiating at approximately 4 pm in Windsor and exiting Eastern Ontario by 11 pm. Risks include: torrential downpours, lighting and isolated damaging winds. A potentially stronger second round of thunderstorms (along an advancing cold front) may happen on Sunday evening/overnight, across Extreme Southwestern Ontario. There is some uncertainty regarding the evolution of thunderstorm development. If thunderstorms do develop, risk factors include: hail and isolated damaging wind gusts.

Across Northern Ontario, a large swath of heavy rainfall is expected. Local rainfall totals nearing 50mm is anticipated.

Alberta

[UPDATED] Severe Thunderstorms Possible in the Prairies

Isolated severe thunderstorms are possible today (Monday June 25th, 2018) and tomorrow (Tuesday June 26th, 2018) in the Prairies.

MONDAY:
A cold front will act as a trigger for severe thunderstorms today in Alberta.

The greatest risk for severe will center itself north of highway 43 and along and west of highway 63. Much of the severe activity looks to be staying south of Fort McMurray.

Environment Canada (PASPC) has placed this region in a “severe” risk on their map. Highlighting the risk for 3-6cm hail. Other threats include damaging winds in excess of 90km/h, and frequent lightning.

Environment Canada forecast map for today – highlighting the severe risk in Alberta. Please note: these maps are still in the experimental stage and are not currently operational.

TUESDAY:
A disturbance and associated cold front will move Eastwards out of Alberta tonight into Saskatchewan. The disturbance is expected to deepen as it centres itself over Central Saskatchewan Tuesday Afternoon.

The cold front will act as a trigger for thunderstorms in Eastern Saskatchewan and Southwestern Manitoba between 2pm and 8pm – West to East.

Some of these storms could turn severe with frequent lightning, large hail, torrential rainfall and strong winds.

Environment Canadas Convective Discussion for Tuesday, June 26th.