ZCZC SPCSWOMCD ALL
ACUS11 KWNS 301639 
SPC MCD 301639 
PAZ000-MDZ000-VAZ000-DCZ000-WVZ000-301845-

Mesoscale Discussion 1743
NWS Storm Prediction Center Norman OK
1139 AM CDT Tue Jul 30 2024

Areas affected...Pennsylvania...Maryland...and Virginia...including
Washington D.C.

Concerning...Severe potential...Watch unlikely 

Valid 301639Z - 301845Z

Probability of Watch Issuance...20 percent

SUMMARY...Initially isolated thunderstorms should increase in
coverage through the afternoon hours with an accompanying increase
in damaging wind potential. Watch issuance is not anticipated given
a weak kinematic environment.

DISCUSSION...GOES imagery and lightning data over the past 30-60
minutes have shown steadily deepening/intensifying convection along
a residual outflow boundary and weak surface trough from central PA
southward into VA. While ongoing convection currently appears to be
sub-severe based on MRMS hail metrics and regional velocity data,
temperatures warming into the low 80s should promote SBCAPE values
up to 2000 J/kg that will likely result in additional thunderstorm
development as well as some degree of intensification through the
day with an attendant potential for damaging wind gusts. Given weak
deep-layer flow over the region, overall convective intensity will
likely be influenced primarily by low-level heating/destabilization.
This will be modulated by how quickly residual low-level stratus can
clear ahead of developing storms. If stronger diurnal heating can be
achieved (i.e. surface temperatures into the mid/upper 80s) then
higher SBCAPE (possibly up to 3000 J/kg) and steeper low-level lapse
rates will likely favor more intense convection with a relatively
higher damaging wind threat. Regardless, watch issuance is not
anticipated given the meager deep-layer wind shear and uncertainty
regarding the thermodynamic environment.

..Moore/Gleason.. 07/30/2024

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

ATTN...WFO...PHI...BGM...AKQ...CTP...LWX...RNK...

LAT...LON   36907919 36927952 36977980 37067997 37218002 37357993
            37687957 38087919 38417889 38577878 38787862 39147850
            40067834 40797833 41297813 41727787 41937744 41927699
            41767654 41427634 40847619 40437612 39637603 39267590
            38827602 38167648 37607702 37087765 36907803 36807841
            36847881 36907919 

NNNN