Tag: Isolated severe

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.

Ontario

Stormy Evening & Overnight for Northeastern Ontario

Heavy showers & thunderstorms beginning this afternoon in Sudbury and Algoma District. Continuing through the overnight.

An area of low pressure will rapidly intensify as it tracks through Northern Ontario towards James Bay. A sharp cold front will trigger heavy rainfall and thunderstorms today and tonight across Northeastern Ontario.

THREATS

The primary threat will be torrential rainfall leading to minor flooding. Additionally, small hail and locally strong winds are possible in stronger thunderstorms.

NAM model rainfall projection for Wednesday into Thursday.

Rainfall totals in the range of 30-60mm is expected north of Manitoulin Island & East of Lake Superior.

Thunderstorm Outlook from Environment Canada

Ontario

Isolated Severe Storms Slice Humidity in Ontario & Quebec

Scattered thunderstorms are expected across the lower half of Southern Ontario and Southwestern Quebec today (July 2nd, 2018).

A weak cold front will slowly track across Southern ON/SQUE today acting as a trigger for thunderstorms. The frontal passage is not expected to offer much relief from the heat, but will lower humidity to more comfortable levels tonight and Tuesday.

The primary risk with these thunderstorms will be torrential rainfall. Due to slow movement of the frontal passage some thunderstorms may “train” or, regenerate over the same region bringing locally 30-50mm in a short period of time. Additionally, isolated damaging winds are possible – primarily in Eastern Ontario and Southwest Quebec where the greatest risk for severe exists. Small hail between pea and dime size is possible in the more robust updrafts across the entire isolated severe risk zone.

The timing for storm development today, will be between 11am-6pm. We have highlighted localized municipalities – stretching from the Golden Horseshoe into Eastern Ontario in a isolated severe threat.

Like what we do? Consider sharing us with your friends and family.