Storm Prediction Center Mesoscale Discussion 1489

   Mesoscale Discussion 1489
   NWS Storm Prediction Center Norman OK
   1111 AM CDT Sun Jun 30 2024

   Areas affected...Portions of central/eastern NC/VA...MD...and DE

   Concerning...Severe potential...Severe Thunderstorm Watch likely 

   Valid 301611Z - 301815Z

   Probability of Watch Issuance...80 percent

   SUMMARY...Thunderstorms are expected to develop over the next couple
   of hours, posing a risk for damaging wind gusts. A watch will likely
   be needed for portions of the region withing the next 1-2 hours.

   DISCUSSION...Portions of northern VA into MD/DE continue to
   experience greater cloud cover at midday due to earlier day
   convection. The airmass across this area has been slower to recover
   as heating has been somewhat slower than surrounding areas.
   Instability increases with southward extent, and to the east of a
   surface trough, across southeast VA into northeast NC. With time,
   much of the region should achieve moderate to strong destabilization
   given surface dewpoints in the mid 70s F and temperatures climbing
   into the upper 80s/low 90s F. Vertical shear will be strongest
   (around 25-30 kt effective shear magnitudes) across northern
   VA/MD/DE, while decreasing with southward extent into NC. 

   Convection may first develop in the uncapped and moderately unstable
   airmass near the surface trough across parts of NC into southeast
   VA. As airmass recovery continues across northern portions of the
   MCD area, additional storms are expected to develop over the higher
   terrain of northern VA and shift east through late afternoon/early
   evening. Thunderstorm clusters will mainly pose a risk of damaging
   gusts, with potentially some better organized/more intense bowing
   segments possible further north where better shear overlaps the
   moderately unstable airmass. Regardless, portions of the MCD area
   will likely need severe thunderstorm watch issuance within the next
   1-2 hours.

   ..Leitman/Gleason.. 06/30/2024

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

   ATTN...WFO...PHI...AKQ...MHX...LWX...RAH...RNK...

   LAT...LON   38267896 39487737 39637579 38897528 36947495 35997518
               35347621 35307850 35377947 35828018 36298023 37088010
               37567970 38267896