Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts…

 

Today

NB/Labrador:  Scattered afternoon thunderstorms. A chance of becoming severe over NB.

NS/PEI/NL:  None.

 

Tonight

Labrador:  A chance of thunderstorms late Monday morning.

NB/NS/PEI/NL:  None.

 

Monday

NB/Labrador:  A chance of afternoon thunderstorms.

NS/PEI/NL: None.

 

Convective Discussion…

A trough of low pressure tracking across Labrador will give scattered afternoon thundershowers over portions of Labrador. Cape values are near 500 J/kg so any cells that form are no likely to be severe. Over New Brunswick, surface based thundershowers that could become severe are possible this afternoon. There are no real surface forcing mechanisms but Cape values are 500-1000 J/kg and shear is linear at 40 knots.  There is the potential for heavy rain at times as PWAT values are near 30 mm. There is also a supportive right entrance to an upper level jet to give support.

 

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

Thunderstorm Outlook for Tomorrow

Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts…

 

Today

NB/NS/PEI/NL:  A chance of thunderstorms.

Labrador:  None.

 

Tonight

NB/NS/PEI/NL:  A chance of thunderstorms.

Labrador:  None.

 

Sunday

NB/PEI/Labrador: A chance of thunderstorms. Over New Brunswick, surface based storms will may give severe weather in the afternoon.

NS/NL: None.

 

Convective Discussion…

A trough of low pressure tracking across the Maritimes will give a chance of embedded thundershowers for those areas today. There is the potential for heavy rain at times as PWAT values are 30-50 mm. Surface based thundershowers are possible this afternoon over portions of Newfoundland but the CAPE values are less than 500 J/kg so they should stay non-severe. On Sunday, surface based thundershowers are expected over most of New Brunswick and portions of Labrador. Over Labrador the CAPE values are expected to be less than 500 J/kg so non-severe cells are expected. Over New Brunswick, CAPE values near 1000 J/kg and shear of 30-40 knots will help support possible severe thunderstorms.

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

Thunderstorm Outlook for Tomorrow

Convective Outlook Valid for Today, Tonight and Tomorrow

Regional Impacts

Scattered to widespread thundershowers are expected across NB later today and overnight tonight across Fundy shores. Some storms near Grand Falls and the Trans-Canada Highway over western NB could reach severe limits due to hail and heavy rain (and wind gusts). Severe storms are expected to be quite isolated. The general thundershowers will extend across the Northumberland and Gulf marine regions.

 

Convective Discussion

The frontal analysis today is complex. A trailing cold front across eastern Labrador may spawn a few lightning strikes today. Another cold front currently located over the St. Lawrence river approaching the Gaspe peninsula will act as a trigger this afternoon for storms in NB and western PEI. Storms near the American border will have decent jet support, and 0-6k shear over 35kts. Moderate hail is possible *IF* a discrete cell can form in a clearing of the prevailing cloudy skies. Overnight, this trough-ing will force embedded thunderstorm development along Fundy shores and western NS. On Saturday, this instability becomes quite widespread across Atlantic Canada with rain being the main hazard. Sunday brings in stabilizing conditions throughout the day.

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

Thunderstorm Outlook for Tomorrow

 

Thunderstorm Outlook for Sunday

 

Forecaster: Tirone.

Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts

Scattered thunderstorms this afternoon and evening across western and possibly northern LAB. Gusty winds, small hail and brief downpours are likely.

 

Isolated thunderstorms possible for central NB Friday afternoon.

 

Convective Discussion

Warm frontal trough crossing LAB today will be followed by an approaching cold which will likely give scattered thunderstorms across the west, and possibly the north coast later in the day. The LA Grande TEP has about 30-35 knots of shear, and also a fairly decent LLJ so some cells could get close to being severe. But the instability is not that great, and CAPE is nothing to write home about (in the vicinity of 500 J/KG – based on lifting from a surface temperature of 22 or so).  Lastly there are not too many breaks in the SC deck upstream so unless things break open soon it might be difficult getting deeper cells. For now, a compromise of gusts to 70 km/h or so and small hail seems to be legit.

 

On Friday a weak surface boundary and short wave trough could give some isolated afternoon storms for a portion of central NB. Locally heavy downpours seems to be the main threat.

 

A side note: there is some indication of isolated convection tonight and early Friday morning for parts of the island portion of NL associated with a weak short wave, but confidence is pretty low on that scenario.

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

Thunderstorm Outlook for Tomorrow

 

Jeremy

Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts

Slight chance of an afternoon thunderstorm for a portion of the north Labrador coast.

On Thursday a better chance for thunderstorms for western areas of Labrador.

 

Convective Discussion

The frontal trough that gave some scattered thunderstorms to a good chunk of the Big Land Tuesday is still hanging on near the coast so a slight chance for the north coast (Nain area) this afternoon. Further south there will likely be some TCUs inland from Norman Bay down to Mary’s harbour/Lodge Bay area with just the very slight chance of a rumble or 2 of thunder. Upstream TEPs have decent lapse rates in the low/mid levels but a strong cap around 600 mb will limit CAPE vales to about 200 J/KG or so.

 

Thursday afternoon has a decent potential for thunderstorms across western areas of LAB in the wake of a warm front and ahead of an advancing cold front. Strong wind gusts, small hail and brief downpours seem possible at this time.

 

Meanwhile the Island portion of the province, as well as the Maritimes, remain quiet.

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

Thunderstorm Outlook for Tomorrow

 

Jeremy