Mesoscale Discussion 1628
NWS Storm Prediction Center Norman OK
1205 PM CDT Sat Aug 28 2021
Areas affected...South-Central Pennsylvania...Western
Maryland...Eastern West Virginia...and Northern Virginia
Concerning...Severe potential...Watch unlikely
Valid 281705Z - 281900Z
Probability of Watch Issuance...5 percent
SUMMARY...Isolated damaging wind gusts possible with the strongest
storms this afternoon.
DISCUSSION...Visible satellite shows strong insolation this morning
has given way to scattered convective development over the northern
part of region. Surface temperatures have warmed into the mid 80s F
amid rich low-level moisture (dew point temperatures in the upper
60s and low 70s F). This is yielding around 1000 J/kg of MLCAPE.
With weak convective inhibition and continued
heating/destabilization, additional pulse-like storms are expected
to develop throughout the afternoon and gradually move southeastward
with time. Weak flow throughout the atmosphere will limit storm
organization, however, a few isolated damaging wind gusts will be
possible with the strongest storms given at least marginal low-level
lapse rates near 8 C/km that should develop, particularly over parts
of northern Virginia and vicinity later this afternoon. Given the
expectation for an isolated damaging wind threat, watch issuance is
not expected.
..Karstens/Grams.. 08/28/2021