Thunderstorm Outlook Valid for Today and Tomorrow

Thunderstorm Outlook for Day 1 – JUNE 27th 

 

Regional Impacts 

Isolated thunderstorms are expected this afternoon and evening across central and parts of northern New Brunswick. In central NB, a cell or two could approach severe limits today for heavy rainfall of 25-40mm. A few lightning strikes are also possible along an elongated boundary in Labrador. 

 

Convective Discussion 

Today's thunderstorm risk is highly dependent on synoptic cloud location. The moisture is certainly available with >20 degree dew points. The limiting factor could be the daytime heating needed to overcome a weak cap at 700mb. If highs near 30 can be achieved, then heavy rainfall is the main hazard. Low-mid level shear values are more favourable for severe weather on Day 2 (dynamics advecting in from west). 

 

 

 

Thunderstorm Outlook for Day 2 

 

Regional Impacts 

Severe thunderstorms are possible in southern and central New Brunswick. Isolated, non-severe thunderstorms are also possible near the Cobequid pass in Nova Scotia. Hot daytime highs, and dew points remaining near 20 will facilitate this. 

 

Convective Discussion 

800-1200J/kg of sfc based CAPE can be realized, with ample sfc-midlevel moisture, 16-18 degree T diffs from 500-700mb, and 35-40kts of 0-6k shear. Pwats near 50mm make heavy rain, small hail – FL at 11,000ft – and gusty winds the main hazards. Low level helicity does not appear elevated at this time. Check back tomorrow for an updated OUTLOOK. 

 

 

Convective Outlook Valid for Today and Tomorrow

Thunderstorm Outlook for Today

Regional Impacts

Isolated thunderstorms over western Labrador this afternoon and into the evening. the main threat will be brief heavy downpours and high wind gusts.

Convective Discussion

A weak surface cold front extending through northern Quebec will advance towards Labrador this afternoon. Colder air aloft will destabilize the airmass between Shefferville and Wabush, and then around Churchill Falls late in the day. The La Grande sounding was modified with a Ts,Td combination of 23,14 which was enough to generate CAPE values of 250+ J/kg  and Lifted index of -1. The hodograph is showing unidirectional winds through the unstable column and a westerly shear / Jet of 50kt - which would be enough to sustain these isolated pulse thunderstorms a little longer, which could in turn could produce surface gusts of 35kt or more.

   

Thunderstorm Outlook for Sunday

Convective Outlook Valid for Today and Tomorrow

Thunderstorm Outlook for Today

 

Regional Impacts

Slight risk of a non-severe thunderstorm over westernmost NS this evening and after midnight.

 

Convective Discussion

Moisture associated with a weak low pressure area over the Gulf of Maine will continue to advance over the

southern Maritimes during the day. Bands of showers along with an isolated thunderstorm will be moving through

Fundy and Lurcher.

 

 

Thunderstorm Outlook for Saturday

 

For Saturday, Risk of non-severe thunderstorms over western and central Labrador.

 

 

Convective Outlook Valid for Today and Tomorrow

Regional Impacts

Nil.

 

Convective Discussion

No thunderstorms expected in the region today. Some isolated thundershowers over MRTM waters south of NS overnight tonight and into Friday morning.

 

Thunderstorm Outlook for Day 1

 

Thunderstorm Outlook for Day 2

 

Jeremy

Convective Outlook Valid for Today and Tomorrow

Thunderstorm Outlook for Day 1

 

No thunderstorms expected at this time. There is small chance of a lightning strike or two this afternoon over SE Labrador, GNP, and Green Bay-White Bay as the trough passes through.

 

Thunderstorm Outlook for Day 2

 

No convective activity expected for Day 2 at this time.