[BNAWX] Severe Storm Outlook Narrative

[EMWIN Server]

ACUS11 KWNS 020439
SWOMCD
SPC MCD 020439
MDZ000-VAZ000-WVZ000-NCZ000-TNZ000-020615-

MESOSCALE DISCUSSION 1360
NWS STORM PREDICTION CENTER NORMAN OK
1139 PM CDT SUN JUL 01 2012

AREAS AFFECTED...PORTIONS WRN NC...NRN THROUGH SWRN VA...WRN/CENTRAL
MD...ERN PANHANDLE OF WV.

CONCERNING...SEVERE THUNDERSTORM WATCH 452...

VALID 020439Z - 020615Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 452
CONTINUES.

SUMMARY...BEST-ORGANIZED WIND-DAMAGE POTENTIAL WILL CONTINUE TO BE
WITH MCS MOVING SEWD ACROSS SPINE OF APPALACHIANS IN SWRN
VA...EXTREME NERN TN AND INTO ADJOINING NWRN NC.  SOME UNCERTAINTY
EXISTS AS TO HOW FAR SE THIS ACTIVITY CAN MAINTAIN SVR GUST
THREAT...GIVEN ITS WELL-DEVELOPED COLD POOL AND ISALLOBARIC
PERTURBATIONS COUNTERACTED BY INCREASINGLY STABLE AIR THAT IT WILL
ENCOUNTER.  OVERALL ENVIRONMENTAL INDICATIONS ARE THAT GEN WEAKENING
TREND SHOULD OCCUR NEAR AND SE OF EXISTING WW EDGE...LOCAL/TEMPORARY
 FLUCTUATIONS ASIDE.  WITH SVR POTENTIAL EXTENDING BEYOND SRN
PORTIONS OF CURRENT WW AREA...HOWEVER...ADDITIONAL/SMALL WW MAY BE
NEEDED.

DISCUSSION...MOST SFC OBSERVATIONS OVER WHICH THIS COMPLEX HAS
PASSED DURING PAST COUPLE HOURS SAMPLED SUB-SVR GUSTS...HOWEVER BKW
AND PSK MEASURED 51 AND 56 KT GUSTS WITHIN PAST HOUR.  GUST FRONT
APPEARS TO BE STAYING SEVERAL MILES AHEAD OF PARENT REFLECTIVITY
CORES OVER SWRN VA AND ADJOINING NC BORDER.  COMPLEX WILL BE MOVING
INTO AIR MASS CHARACTERIZED BY PROGRESSIVELY STRONGER MLCINH AND
WEAKER MLCAPE...BOTH WITH SEWD EXTENT AND WITH TIME...RELATED TO
1. OUTFLOW AIR FROM EARLIER/WELL-ORGANIZED MCS ACTIVITY...AND
2. DIABATIC SFC COOLING THROUGHOUT AREA...AFFECTING BASE OF
RELATIVELY DRY SUBCLOUD LAYER SAMPLED BY 00Z GSO RAOB.
MODIFIED RAOBS AND FCST SOUNDINGS SUGGEST DRY AIR ABOVE COOLING
SKIN-LAYER WILL AID IN DOWNDRAFT ACCELERATION...ESPECIALLY NW OF
DAN-GSO-AVL LINE.  DEEP-LAYER SHEAR WILL REMAIN WEAK...SO ACTIVITY
WILL CONTINUE TO BE DOMINATED BY FORWARD-PROPAGATIONAL INFLUENCES
UNTIL GUST FRONT NO LONGER IS STG/STEEP ENOUGH TO FORCE CONVECTIVE
LIFT OF WEAKLY UNSTABLE AIR MASS.

FARTHER NE...AIR MASS JUST ABOVE SFC OVER CENTRAL/NRN VA IS MORE
MOIST/UNSTABLE THAN FARTHER S...BUT ALSO WILL EXPERIENCE WEAKER LIFT
ALONG LEADING EDGE OF ITS PORTION OF CONVECTIVE PLUME.  SVR THREAT
OVER THIS AREA IS NONZERO BUT MORE CONDITIONAL...AND LIKEWISE SHOULD
DIMINISH WITH TIME DUE TO GRADUAL DIABATIC SFC
COOLING/STABILIZATION.

..EDWARDS.. 07/02/2012

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

ATTN...WFO...AKQ...LWX...RAH...RNK...GSP...MRX...

LAT...LON   36058280 36668140 38127916 39457835 39417687 38977722
            36307917 35278096 35268233 36058280



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