Convective Outlook valid for Today, and Tomorrow

ECCC Thunderstorm Outlook valid for July 16^th, 2022.

 

Regional Impacts

Isolated non-severe thundershowers are possible in northern NB, and western Labrador as a disturbance in Quebec affects the region.

 

Convective Discussion

With a warm frontal approach, a few showers may spark lightning across the northern tier of New Brunswick and western Labrador this afternoon. Moisture in this airmass is far less than yesterday across the Maritimes, and ML CAPE at best is only near 300 J/kg. Storms do not have good upper dynamics so they are expected to be short lived in nature. With the return of the Maniwaki sounding, confidence in model initialization has increased.

 

Thunderstorm Outlook for Day 1 - SATURDAY

 

Thunderstorm Outlook for Day 2 - SUNDAY

*broad risk of thunderstorms across most areas as an upper trof can trigger convection in a growingly humid airmass. If heat warning criteria is reached, a few cells in the Annapolis valley could push severe limits briefly.  

 

Forecaster: TIRONE

Convective Outlook valid for Today, and Tomorrow

ECCC Thunderstorm Outlook valid for July 15^th, 2022.

 

Regional Impacts

Broadly, scattered non-severe thunderstorms are possible over many regions of Atlantic Canada this afternoon and evening. Additionally, isolated severe thunderstorms are possible in areas of Nova Scotia and eastern portions of New Brunswick.

 

Convective Discussion

As sticky humidity continues across the Maritimes today, the risk for thunderstorms follows suit. With dew points expected to remain near 17C, and some good pockets of direct solar heating, things should fire off this afternoon. Upper features are in place to sustain storms today especially near Truro and Bathurst to severe limits. Hail, gusty winds, and heavy rainfall can all be expected under a strong cell. Lapse rates of 500-700mb are similar to yesterday across Maine and NB (16-18). ML CAPE values are a bit better than yesterday near 1200J/kg, and 0-6k shear is 35-40Kts. Development of storms will be monitored closely and watches may be required. Storm motion today is expected to be E-ly at 15kts. A supercell will head SE at similar speeds should it develop. Additionally, the sweeping cold trof from the decaying Labrador low will spark a few thundershowers in marine waters and some areas of Newfoundland. The dynamics at play in these regions are much weaker.

 

Thunderstorm Outlook for Day 1

 

Thunderstorm Outlook for Day 2

*slight risk of thundershowers across northern tier of NB, and extreme western Labrador as upper trof continues to affect central Quebec.

 

Forecaster: TIRONE

Convective Outlook valid for Today, and Tomorrow

Thunderstorm Outlook valid for July 14^th, 2022.

 

Regional Impacts

Isolated non-severe thunderstorms are forecast today for areas in Labrador, western New Brunswick, and offshore over the slope waters.

 

Convective Discussion

Thundershowers are possible near the low centre in the Labrador sea and over the Big Land. In NB, thundershowers are also possible north of Fredericton this afternoon in an area of clearing already apparent on satellite. Dew points are moist enough to trigger surface convection, with CAPE values 500-700J/kg. The second part of the story is tonight as a shortwave trof swings into the humid airmass from the west near midnight. This is the dynamic feature that will cause nocturnal thunderstorms over the province, and parts of PEI. Pwats are near 30mm, and 0-6k shear values near 30kTs. The biggest hazard is pockets of heavy rain and lightning.

 

Thunderstorm Outlook for Day 1

 

Thunderstorm Outlook for Night 1

 

Thunderstorm Outlook for Day 2

*Thundershowers still possible along broad frontal feature stemming from Labrador low.

 

Forecaster: TIRONE

Convective Outlook Valid for Today and Tomorrow

Regional Impacts

For Nova Scotia… there is a low likelihood that thunderstorms will occur however thunderstorms that do develop have the potential to produce small hail, heavy downpours and strong wind gusts. Primarily over central and eastern parts of the province.

For Labrador… some embedded thunderstorms are possible.

 

Convective Discussion

 

Once again the favourable dynamics will be the primary driver of organised thunderstorm activity today. Overall Cape will be modest with values between 500 and 1000 j/kg but wind shear values are fairly significant with over 50 knots of deep shear. The initiation of thunderstorms will depend largely on the timing of the cooling at 850 and depth of the moisture available near the surface. Thunderstorms are most likely to develop along the spine of NS and track northeastward, affecting areas of central through to eastern and possibly northern NS. These storms, should they develop are likely produce small to moderate hail and heavy downpours. Given the dry mid levels and significant DCAPES there is a good chance for strong surface wind gusts with these thunderstorms. Watches may be issued if some convective initiation triggers deep convection.

 

ML

 

Thunderstorm Outlook for Day 1

 

Convective Outlook Valid for Today, Tonight and Tomorrow

Regional Impacts

For Labrador… some embedded thunderstorms could lead to locally heavier rainfall this evening.

For New Brunswick… potentially severe thunderstorms could affect northern New Brunswick late this afternoon. Small hail with strong wind gusts and potentially heavy downpours can be expected.

 

Convective Discussion

We are looking at very favourable dynamics for the development of severe thunderstorms later this afternoon. Aloft the 250 mb jet will be in a good position for enhanced vertical motion later today with the exit region over northern New Brunswick. The windshear through to mid-levels is favourable for the development of supercells or possibly bow echoes, but it is still possible that a QLCS( Quasi Linear Convective System) could form west and move over New Brunswick later today. One remaining concern if the amount of available low level moisture and CAPE, but with the approaching upper trough the atmosphere will destabilize at some point today. Needless to say a large variety of possible outcomes, but in all likelihood severe winds will be the main concern should thunderstorms develop. Watches may be issued a little later today once we have some stronger indication of the clouds dissipating and more insolation occurring upstream of our area of concern.

 

ML

 

 

Thunderstorm Outlook for Day 1

 

 

Thunderstorm Outlook for Tonight

 

Thunderstorm Outlook for Day 2