“Nocturnal T-Storms” = Metro Flood Watch Thursday AM

After a nice dry stretch of weather, get ready for the next batch of heavy thunderstorms in southern Minnesota.

Another major storm complex, possibly an MCS, is expected to develop Wednesday night into Thursday morning. This time, locally heavy (and potentially flooding) rainfall could be the primary feature of the storms.

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Twin Cities NWS posts a flood watch overnight Wednesday into Thursday morning.

The system:

As the hot dome of high pressure nudges back north into Minnesota Thursday, an upper air disturbance will ride along the periphery of the expanding heat dome into southern Minnesota.

The system will likely trigger a developing MCS with torrential rains overnight.

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NAM model develops heavy storms Wednesday night into early Thursday.

Slow movement may produce multiple inch rainfalls in some areas of central & southern Minnesota by Thursday noon. Some 1″ to 3″+ rainfall totals are quite possible with this system.

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Depending on which model you look at, the heaviest rainfall may be focused in central Minnesota near St. Cloud & Brainerd, and/or near the Twin Cities.

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GFS cranking out 3.5″ of rain for the metro early Thursday!

“Nocturnal” Thunderstorm Season Ahead:

Wednesday night’s storms may be the opening salvo in what meteorologists sometimes call the “nocturnal thunderstorm season.”

Some info about nocturnal thunderstorms:

-They tend to develop and strengthen at night

-They tend to develop and favor warm fronts at the surface

-They tend to roam around the northern periphery of hot high pressure domes.

-They are climatologically favored in late July & August.

Nocturnal storms can produce copious flash flooding rains. Be alert for possible flash flooding in the wee hours of Thursday morning!

PH

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