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Thursday, July 23, 2026

Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts

Today

Lab: Risk of a thundershower.

NS/NL: Risk of a thundershower near the Atlantic Coast.

NB/PEI: Nil

Tonight

NS/NB/PEI/NL/LAB : Nil

Tomorrow

NS/NB/PEI/NL/LAB : Nil

Convective Discussion

The frontal system from yesterday is currently over Northern Quebec. Based on a combination of Water Vapour imagery and observation analysis, the frontal system is beginning to decay, which is progressing it toward a closed-off low-pressure system. As a result, enough remnant forcing remains over Labrador to give rise to isolated thundershowers today, specifically along the Northeastern coast. For the remaining parts of the Maritimes and Newfoundland, the decaying frontal wave is allowing moisture to flow in from the US, likely due to spillover from TS Betha and a building ridge over the Northeast USA. Because of this setup, the plume of moisture and its convective properties can shift with the position of the ridge axis, as well as with how the synoptic setup progresses. Within this plume of moisture, models are indicating CAPE values over 1,500 J/Kg with effective shear values of 30-40KT. One thing to note, however, is that it was intentional to leave the grey region over the Atlantic predominantly off the coast; high-resolution guidance indicates a struggle to push convection inland, while the regional model indicates that convection could move inland. Based on the synoptic setup, it was a conscious effort to go with the high-resolution guidance. 

Thunderstorm Outlook for Today

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Thunderstorm Outlook for Tonight

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Thunderstorm Outlook for Tomorrow

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Forecaster: Lambert