Convective Outlook Valid for Today, Tonight and Tomorrow

Regional Impacts

NS/NB/PEI/NFLD/LAB: None.

Convective Discussion…

A quiet couple of days are in store for Atlantic Canada as a ridge of high pressure settles over the region. Some weak troughing exists over central Labrador this morning, however dry low levels and a lack of instability should prevent any thundershowers from developing this afternoon as the trough slowly drifts south.

Some isolated thundershowers are possible east of Sable Island today around a weak vorticity center, but will remain well offshore.

Thunderstorm Outlook for Today

Thunderstorm Outlook for Tonight

Thunderstorm Outlook for Tomorrow

Forecaster: Copp

Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts

NB, PEI and NS: Scattered showers with a risk of thunderstorms. 15-20mm of rain possible in thunderstorms.

Newfoundland and Labrador: Thunderstorms not expected.

Convective Discussion

Scattered showers and thunderstorms will move slowly across southern New Brunswick into Nova Scotia and possibly PEI today. While updraft strength will be limited, weak upper-level support associated with a jet streak and a 500 hPa trough may aid development. Low freezing levels could allow for small hail. No significant impacts are expected.

Conditions improve tomorrow as fair weather returns.

Thunderstorm Outlook for Today

Thunderstorm Outlook for Tonight

Thunderstorm Outlook for Tomorrow

 

Mel lemmon

Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts

Newfoundland and Labrador: No thunderstorms expected.

Nova Scotia and PEI: No thunderstorms expected today, tomorrow scattered weak thunderstorms possibly giving 10 to 20mm of rain.

New Brunswick: Weak thunderstorms over northern areas today, spreading southward tomorrow with 15 to 20mm of rain possible in heaviest showers.

Convective Discussion

This is the first official thunderstorm outlook of the season, and it’s starting off relatively quiet. A weak surface trough moving slowly across the Maritimes will bring a low chance of thunderstorms to northern New Brunswick today.

Tomorrow, that surface trough will align with a weak upper-level trough, leading to a slightly increased potential for showers and thunderstorms overall. Southern New Brunswick, northern Nova Scotia, and possibly PEI could receive upwards of 15–20 mm of rainfall, although there remains some uncertainty as to whether those amounts will be realized.

The exact location and intensity of precipitation may shift as the upper low evolves tomorrow.

Thunderstorm Outlook for Today

Thunderstorm Outlook for Tonight

Thunderstorm Outlook for Tomorrow

Convective Outlook Valid for Today, Tonight and Tomorrow

Regional Impacts

Today: Slight chance of an isolated thundershower along the Maine/New Brunswick border this afternoon.

Tonight: Risk of some isolated thundershowers over western New Brunswick before noon tomorrow.

Tomorrow: Chance for some scattered thundershowers across New Brunswick tomorrow. Locally heavy downpours are the main risk.

Convective Discussion…

Today, an upper low over southern Quebec will slowly move east as another intensifying low pressure system tracks off the Atlantic coast. Between these two systems, some convection has already fired over southern Maine under the left exit of the upper jet. This area will slowly move north and east through the day, likely triggering more convection through central Maine this afternoon. Due to the slow moving nature of the upper low, most of the thunderstorm activity today will remain west of the border, though a few cells may potentially cross into New Brunswick later this afternoon. Persistent low level cloud cover over southwestern New Brunswick should keep this risk fairly low, with MLCAPE values expected to remain well below 500 J/kg. Slightly better CAPE is expected in central Maine today, where cloud cover is more sparse allowing surface temperatures to rise. Although adequate bulk shear is in place, minimal instability and fairly weak lapse rates over New Brunswick should keep any storms from becoming severe.

Tonight, the upper low will continue to meander towards New Brunswick, crossing the province tomorrow. A similar environment to what is over Maine today will be in place over central New Brunswick tomorrow, bringing a slightly higher chance for some scattered thundershowers that may bring some locally heavy downpours.

Thunderstorm Outlook for Today

Thunderstorm Outlook for Tonight

Thunderstorm Outlook for Tomorrow

Forecaster: Copp

Convective Outlook Valid for Today, Tonight and Tomorrow

Regional Impacts

Today: Risk of some isolated thundershowers in Newfoundland this afternoon. Locally heavy downpours are the main risk.

Tonight: No thunderstorms forecast.

Tomorrow: Slight chance of an isolated thundershower over western New Brunswick in the afternoon.

Convective Discussion…

As a ridge of high pressure dominates the Maritimes today, a weak shortwave will cross Newfoundland bringing the risk for some isolated thundershowers. Meager MLCAPE values (<500 J/kg) and weak bulk shear (15-20 knots) will keep any storms from becoming severe this afternoon, but a few locally heavy downpours are possible. An additional risk area exists in southwest Labrador, associated with a broad trough extending from western Labrador to southern Ontario, but there is a less conducive environment here.

Tomorrow, the above mentioned trough will slowly move east reaching western New Brunswick late in the day. This will bring the slight risk of some isolated thundershowers to extreme western New Brunswick late tomorrow. Most of the activity is expected to remain west of the Maine/New Brunswick border due to the timing of the trough.

Thunderstorm Outlook for Today

Thunderstorm Outlook for Tonight

Thunderstorm Outlook for Tomorrow

Forecaster: Copp