Tag: Falling Temperature

Ontario

[UPDATED] Freezing Rain & Power Outage Risk Across Portions…

A risk of freezing rain supersedes an early February warm-up. A temperature roller coaster with a risk of freezing rain will be the story this week across Southwestern Ontario.

Rainfall and above seasonal temperatures are the story this evening into the overnight. Rainfall ends before morning, with temperatures falling throughout the day.

Be mindful around streams and creeks Tuesday morning. As well as, on roadways, where standing water could lead to hydroplaning. Rainfall and snow-melt will lead to higher water levels. Stay tuned to your local Conservation Authority for the latest information.

A freezing rain risk develops by Wednesday morning. This may be an extended period of freezing drizzle & freezing rain for locales north of Lake Erie, including the 401/402 corridor. Local freezing rain accretion may approach or exceed 15mm. Ice pellets and patchy freezing drizzle will be the story for the rest of Southwestern and Central Ontario.

Projected Freezing rain between Wednesday & Thursday AM. Freezing rain will also track east of Lake Huron. Hamilton-Brantford will be at risk for 15mm of ice accretion and power outages.

There will be two waves of precipitation. The second translates across the region Thursday along a developing low-pressure system. There is some uncertainty in regards to the evolution of this system. Current model guidance suggests a northerly track, leading to a surge in temperatures (above freezing) across Southern Ontario, Thursday. This would be a big snow maker across Northern Ontario & Quebec.

Projected Power Outages Through Wednesday Evening.

Sporadic power outages are anticipated across portions of Southwestern Ontario. A stiff northeasterly wind (aiding in low-level cold delivery), will be enhanced over Lake Ontario. Bringing wind gusts to 40km/h downwind of the lake. Sporadic power outages will begin throughout the evening. Peaking between 8pm-12am Wednesday. An extended period of freezing drizzle will succeed the initial wave of convective-driven freezing rain. For regions East of the Escarpment, through South Central Ontario & the Northern GTA this will be a primarily ice pellet event. Briefly beginning as snow, especially stretching from the Bruce Peninsula through Northern sections of Central Ontario.

Charge those devices! And stay tuned.

Manitoba

Early Fall Snowfall Strikes Manitoba & Saskatchewan

Tricky driving associated with an early taste of winter across Southern Saskatchewan & Southern Manitoba.

Snow begins today in Saskatchewan and Southwestern Manitoba, persisting into Wednesday across Manitoba and Northwestern Ontario.

SYNOPSIS:

A boundary separating cold and warm air will descend Southwards across Southern Saskatchewan & Southern Manitoba through Tuesday allowing temperatures to dip near the freezing mark. A drop in temperatures near freezing or just below is expected along a narrow band of light-moderate snow developing across the Southern Prairies. Concurrently, an area of low pressure will strengthen through Wednesday, as it tracks out of Montana into the Dakotas. 

A narrow band of snowfall situated across Western Saskatchewan will increase in coverage and intensity throughout the evening, spreading across all of Southern Saskatchewan and Manitoba tonight. Continuing across a narrow corridor of Manitoba and Northwestern Ontario Wednesday.

This will be wet snow event for southwestern Manitoba (including Brandon). Light tree damage due to heavy-wet snow is possible Wednesday. 

EXPECTED ACCUMULATIONS:

5-15cm is expected across a narrow swath from Extreme Southern Saskatchewan through Southern Manitoba.

Winnipeg will see a cold rain, changing over to wet snow. Timing of the changeover to wet snow is leading to uncertainty, regarding accumulation.

Higher elevation in the Parklands Region, may see higher accumulations near, or exceeding 20cm. Including Riding Mountain National Park and the Dauphin area. 

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.