ACUS11 KWNS 092044
SWOMCD
SPC MCD 092043=20
NJZ000-PAZ000-MDZ000-DEZ000-VAZ000-092245-

Mesoscale Discussion 1620
NWS Storm Prediction Center Norman OK
0343 PM CDT Wed Jul 09 2025

Areas affected...Portions of
Maryland...Delaware...Pennsylvania...and New Jersey

Concerning...Severe Thunderstorm Watch 497...

Valid 092043Z - 092245Z

The severe weather threat for Severe Thunderstorm Watch 497
continues.

SUMMARY...Convective trends are being monitored for the need for
downstream watch issuance across parts of Maryland, Delaware,
Pennsylvania, and New Jersey as storms spread east through early
evening.

DISCUSSION...Regional radar mosaics continue to show a slow, but
steady, increase in convective coverage across southern PA and parts
of northern MD as lift associated with a mid-level impulse continues
to migrate east and overspreads a moderately buoyant air mass.
Regional VWPs continue to sample 30-40 knot mid-level flow
associated with the upper feature, but the nebulous forcing for
ascent and modest mid-level lapse rates appear to be modulating
convective intensity and longevity of more discrete cells across
PA/MD. While the convective parameter space is supportive of
organized/severe convection, it remains unclear how intense
convection will become over the next few hours.=20

Further south into eastern MD and DE, confidence is higher in a
severe wind threat later this evening. A squall line is slowly
organizing across central VA and is expected to continue
intensifying over the next few hours (see recently issued MCD #1619
for additional details). Recent surface observations and MLCAPE
analyses show a plume of rich low-level moisture/buoyancy extending
into southern DE/southeast MD, which should maintain the convective
line as it spreads east into the evening hours. Slow storm motions
cast some uncertainty on exactly when a downstream watch will be
needed, but recent high-res guidance suggest a damaging wind threat
will begin to materialize between 23-01 UTC.

..Moore.. 07/09/2025

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!6BPqjJ7X8df9vWU7Sv-e-tVdqi52I3sQecuzfZijOEU01bidp7bDFLAitauzXHyom5BPxP03t= roYWtw9LNkM3DnsCZ8$ for graphic product...

ATTN...WFO...PHI...AKQ...CTP...LWX...

LAT...LON 39057445 38737476 38387493 38137505 37887521 37787541
37867579 38117608 38547620 39057635 39297654 39487691
39717717 39927727 40127722 40397661 40527587 40457514
40247461 40057432 39787409 39477417 39057445=20

MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN


=3D =3D =3D
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