MESOSCALE DISCUSSION 1318
   NWS STORM PREDICTION CENTER NORMAN OK
   0209 PM CDT MON JUL 18 2016

   AREAS AFFECTED...NRN VA / MD / DE / SRN NJ / FAR SERN PA

   CONCERNING...SEVERE THUNDERSTORM WATCH 396...

   VALID 181909Z - 182015Z

   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 396
   CONTINUES.

   SUMMARY...LOCALIZED POCKETS OF WIND DAMAGE ARE POSSIBLE THIS
   AFTERNOON AS AN APPROACHING SQUALL LINE NEAR THE HIGHER TERRAIN IN
   NWRN VA MOVES EWD TOWARDS THE GREATER D.C. AND BALTIMORE METROS.

   DISCUSSION...RADAR MOSAIC SHOWS A MATURING SQUALL LINE ACROSS THE
   MID-ATLANTIC REGION MOVING EWD AROUND 30 KT.  SURFACE CONDITIONS
   DOWNSTREAM OVER THE POTOMAC RIVER VALLEY/CHESAPEAKE BAY VICINITY ARE
   VERY WARM WITH LOW-MID 90S TEMPS AND DEWPOINTS IN THE LOWER 70S. 
   DESPITE RELATIVELY WEAK WLY FLOW IN THE LOWEST 8 KM...AMPLE PW
   /1.5-1.75 INCHES/ WILL FOSTER SOME LOW-END SEVERE POTENTIAL VIA
   WATER LOADING/WET MICROBURSTS.  ISOLD DAMAGING WINDS WILL BE THE
   THREAT WITH THE STRONGER DOWNDRAFTS.  EXTRAPOLATION OF THE SQUALL
   LINE HAS IT REACHING A BWI TO DCA LINE AROUND 2020-2040Z.

   ..SMITH.. 07/18/2016


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

   LAT...LON   38487855 39787723 39817588 40277502 39907403 38007552
               38077746 38487855