SPC Mesoscale Discussion

SPC MD 1366

MD 1366 Image

Mesoscale Discussion 1366
NWS Storm Prediction Center Norman OK
0336 PM CDT Tue Jul 27 2021

Areas affected...Eastern NY...Southern New England

Concerning...Severe Thunderstorm Watch 395...396...

Valid 272036Z - 272200Z

The severe weather threat for Severe Thunderstorm Watch 395, 396

SUMMARY...Severe potential continues across eastern NY and adjacent
southern New England. Current trends suggest some severe potential
may extend into far southeast NY, far northern NJ, and southern CT.
A watch may need to be considered.

DISCUSSION...Recent radar and satellite imagery show that the main
convective line extends from about 20 miles west of ALB
southwestward into far northeast PA (about 25 miles northeast of
IPT). Updraft strength and duration has varied within the this line,
likely as a result of somewhat modest instability. Estimated storm
motion within the southern end of the line is southeastward around
31 kt, which places it at the southern edge of Severe Thunderstorm
Watch 396 near 22Z. Given the current storm trends and the warm and
moist downstream air mass, some isolated severe threat may persist
into far southern NY and southern CT. Northern portion of the line
continues to move more eastward, with an estimated storm motion
closer to 35 kt. As with areas southwestward, the downstream air
mass is warm, moist, and modestly buoyant, suggesting severe
potential will continue downstream.

In addition to the convective line, some more discrete development
has occurred on the southern edge of a previously decayed cluster of
showers and thunderstorm. More discrete storm character has allowed
for stronger updrafts and a relatively greater chance for a strong

..Mosier.. 07/27/2021

...Please see www.spc.noaa.gov for graphic product...


LAT...LON   43077442 43247395 43487267 43177131 42577081 41857096
            41377178 40757358 40887475 41727660 42497521 43077442 

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