[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 201640
SWOMCD
SPC MCD 201639 
MDZ000-VAZ000-DCZ000-NCZ000-201815-

MESOSCALE DISCUSSION 2239
NWS STORM PREDICTION CENTER NORMAN OK
1139 AM CDT TUE SEP 20 2005

AREAS AFFECTED...SRN MD THROUGH CNTRL VA INTO N-CNTRL NC

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 201639Z - 201815Z

POTENTIAL FOR A FEW SEVERE STORMS CAPABLE OF DAMAGING WINDS AND
LARGE HAIL IS EXPECTED TO INCREASE ACROSS DISCUSSION AREA THIS
AFTERNOON.  CONVECTIVE TRENDS WILL BE MONITORED FOR A POSSIBLE WW
ISSUANCE.

WATER VAPOR IMAGERY AND 12Z UPPER-AIR DATA SHOW SHORTWAVE TROUGH AND
ASSOCIATED 45-50 KT MID-LEVEL WIND MAXIMA TRANSLATING EWD TOWARD THE
CNTRL APPALACHIANS WITH DOWNWIND REGION OF IMPLIED ASCENT BEGINNING
TO SPREAD EWD ACROSS THE PIEDMONT REGION.  RELATIVELY CLOUD FREE
SKIES E OF THE APPALACHIANS HAVE ALLOWED TEMPERATURES TO WARM
THROUGH THE 80S ACROSS THE PIEDMONT AND WHEN COUPLED WITH DEWPOINTS
OF 65-70F...AIR MASS HAS BECOME NEARLY UNCAPPED AND MODERATELY
UNSTABLE /PER MODIFICATION OF 12Z RNK AND IAD SOUNDINGS/.

CONTINUED HEATING/DESTABILIZATION IN CONJUNCTION WITH INCREASING
LARGE-SCALE FORCING FOR ASCENT AHEAD OF SHORTWAVE TROUGH ARE
EXPECTED TO AID IN TSTM DEVELOPMENT OVER HIGHER TERRAIN OF
APPALACHIANS AS WELL AS ALONG WEAK LEE TROUGH. DEVELOPING STEEP
LOW-LEVEL LAPSE RATES AND LARGELY UNIDIRECTIONAL WINDS OBSERVED ON
MORNING RAOBS AND CURRENT VWPS SUGGESTS THE POTENTIAL FOR MAINLY
DAMAGING WINDS WITH MOST INTENSE STORMS.  ISOLATED LARGE HAIL WILL
ALSO BE POSSIBLE.

..MEAD.. 09/20/2005

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...AKQ...LWX...RAH...RNK...

36668010 38007875 38817796 39167744 39127683 38497660
36167878 35997987 36418022 

WWWW