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Saturday, May 30, 2020

Convective Outlook Valid for Today and Tomorrow

Day 1 Thunderstorm Outlook

 

Regional Impacts

For New Brunswick...

There is a slight chance that severe thunderstorms could develop giving strong wind gusts and potentially heavy downpours.

Elsewhere..

A slight chance of embedded thunderstorms giving locally heavier rainfall.

 

Convective Discussion

Overall there is not of lot of instability in the airmass but with cold air advection aloft and some daytime heating surface based CAPE’s should exceed 500 j/kg by this afternoon over New Brunswick. In terms of the dynamics, conditions are very favorable ahead of the approach cold front that will pass over New Brunswick today, with about 50 knots of deep shear to support supercell development. In addition there will be convergence and enhanced low level vorticity along the front. It is possible that supercells could develop with the potential to produce bowing segments leading to strong surface winds. Watches may be required should organized storms begin to develop.

 

Threat Table for reference

Threat

Rainfall Amount

Wind Gusts

Hail Diameter

Tornado Probability

Minor

< 25 mm

< 70 km/h

< 2 cm

Unlikely

Moderate

25 – 50 mm

70 –89 km/h

2 – 4 cm

Low

Severe

50– 100 mm

90– 119 km/h

4 – 6 cm

Moderate

Extreme

100 mm or more

120 km/h or greater

6.0 cm or greater

Elevated

Risk of Thunderstorms: Thunderstorms that develop in this area will be less organized and will not likely meet warning criteria. Severe Thunderstorm Watches will not likely be required.

Slight Risk of Severe Thunderstorms: There is a low probability that weakly organized thunderstorms will develop, these thunderstorms may reach warning criteria. Severe Thunderstorm Watches may be required

Moderate Risk of Severe Thunderstorms: There is a moderate probability that organized thunderstorms will develop, thunderstorms are likely to reach warning criteria. Severe Thunderstorm Watches will likely be issued.

High Risk of Severe Thunderstorms: There is a high probability that well organized thunderstorms will develop, these thunderstorms are likely to meet or exceed warning criteria. Severe Thunderstorms Watches will be issued.

 

Day 2 Thunderstorm Outlook