Storm Prediction Center Mesoscale Discussion 1801

   Mesoscale Discussion 1801
   NWS Storm Prediction Center Norman OK
   1156 AM CDT Sat Aug 03 2024

   Areas affected...portions of the mid Atlantic

   Concerning...Severe potential...Watch likely 

   Valid 031656Z - 031830Z

   Probability of Watch Issuance...80 percent

   SUMMARY...Scattered to widespread thunderstorms will likely pose a
   risk for damaging/severe wind gusts this afternoon and evening.
   Given the potential for organized storms, a WW is likely.

   DISCUSSION...Across the eastern US, a broad positive-tilt mid-level
   tough was observed via early afternoon WV overspreading a warming
   and destabilizing air mass across the Mid Atlantic and central
   Appalachians. Initial thunderstorm development has commenced with
   additional towering cumulus evident over the higher terrain and on
   localized convergence features over much of the Northeast. As
   surface temperatures continue to climb into the upper 80s to low 90s
   F, very moist surface dewpoints in the 70s F will aid in eroding the
   remaining minimal inhibition and continued storm development.
   Moderate to large buoyancy is expected by mid afternoon with MLCAPE
   of 1500-3000 J/kg more than adequate for strong updrafts. Enhanced
   mid-level flow near the upper trough is also supporting 25-35 kt of
   effective shear suggesting some potential for storm organization
   into bands or clusters. While mid-level lapse rates are not overly
   steep, generally 6.5-7 C/km the magnitude of buoyancy and potential
   for more organized multi cells will foster a risk for stronger and
   more sustained downdrafts. High PWATS and water loading will also
   support stronger damaging wind potential with a risk for severe
   gusts from the more organized and persistent cores.

   Early sat/radar trends, coupled with recent HRRR data, suggest
   increasing storm coverage over central PA into northern MD may
   organize into several bands or more persistent multi-cell clusters
   through the early afternoon. As they track east towards the I-95
   corridor and establish stronger surface cold pools, damaging gusts
   are likely. A few of the more persistent or organized linear bands
   may also pose a risk for stronger severe gusts to 65-70 mph. With
   the severe risk increasing through the afternoon, a WW is likely
   needed.

   ..Lyons/Hart.. 08/03/2024

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

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

   LAT...LON   40347691 41617545 42007469 42077411 42017371 41907353
               41307344 40637351 40447392 39527426 39087484 38377679
               38277733 38217749 38007911 38247927 38607899 40267708
               40347691