ZCZC SPCSWOMCD ALL
ACUS11 KWNS 122138 
SPC MCD 122138 
CTZ000-MAZ000-NYZ000-NJZ000-PAZ000-DEZ000-MDZ000-122345-

Mesoscale Discussion 1970
NWS Storm Prediction Center Norman OK
0438 PM CDT Sat Aug 12 2023

Areas affected...parts of eastern PA...northern NJ and far southern
NY State

Concerning...Severe potential...Watch possible 

Valid 122138Z - 122345Z

Probability of Watch Issuance...40 percent

SUMMARY...Isolated severe storms with the potential for damaging
gusts, hail and perhaps a tornado are possible this afternoon
through the early evening. Uncertainty on the severe risk is high,
but a weather watch is being considered.

DISCUSSION...As of 2130 UTC, regional radar analysis showed isolated
thunderstorms ongoing across parts of far eastern PA, NJ and
southern NY State. Thus far, these storms have remained isolated in
coverage ahead of a large cluster of more robust storms over western
PA and northeast OH. Despite limited synoptic forcing for ascent
from the lagging upper trough, the environment ahead of these
isolated storms appears favorable to support some risk for severe
weather this evening. Surface temps in the low to mid 80s are
supporting ~1500 J/kg of MLCAPE with area VADs showing 40-50 kt of
effective shear. With a CAPE/shear parameter space favorable for
supercells, damaging gusts, hail and perhaps a brief tornado appear
possible if storms are able to maintain intensity.

The primary uncertainty with regards to the severe threat is the
expected storm coverage. Broad-scale ascent is weak and thus far
storms have been only marginally organized, likely from lingering
inhibition evident on the 20z ALY sounding. However, recent HRRR
runs suggests additional storm development/organization is possible
through the early evening with a focus across far southern NY state
into portions of northern NJ and far eastern PA. While confidence in
storm evolution and the severe threat is low, conditions will be
monitored for a possible watch.

..Lyons/Thompson.. 08/12/2023

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

ATTN...WFO...OKX...ALY...PHI...BGM...CTP...LWX...

LAT...LON   40177641 40687634 41157528 41377481 41857451 42157433
            42287362 42077335 41707327 41227345 40827370 40397411
            39927446 39657481 39507502 39467533 39527569 39627604
            39677617 40177641 

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