[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 211822
SWOMCD
SPC MCD 211820 
VAZ000-NCZ000-212015-

MESOSCALE DISCUSSION 2070
NWS STORM PREDICTION CENTER NORMAN OK
0120 PM CDT SAT AUG 21 2004

AREAS AFFECTED...S-CENTRAL VA...PORTIONS CENTRAL/WRN NC

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 211820Z - 212015Z

CONVECTION IS INCREASING IN COVERAGE AND INTENSITY ALONG/AHEAD OF
SFC COLD FRONT...FROM DC/BWI AREA SWWD PAST LYH AND INTO
MOUNTAINS/FOOTHILLS OF NC.  AS THIS ACTIVITY MOVES FURTHER INTO VERY
MOIST AND DESTABILIZING AIR MASS OVER VA/NC PIEDMONT...SEVERE
POTENTIAL WILL INCREASE.

SFC ANALYSIS SHOWS COLD FRONT FROM JUST N OF BWI SWWD TO NERN CORNER
OF TN...MOVING EWD 10-15 KT.  PREFRONTAL TROUGH IS EVIDENT FROM
AROUND LYH SSWWD ACROSS CLT AREA.  CONVECTION IS DEVELOPING BETWEEN
FRONT AND TROUGH OVER NC AS WELL AS INVOF FRONT.  AIR MASS OVER
PIEDMONT IS WARMING AGAIN AFTER PASSAGE OF CLOUD BAND MENTIONED IN
MESOSCALE DISCUSSION 2070.  WITH SFC DEW POINTS GENERALLY 70S F
HELPING TO COUNTERACT WEAK MIDLEVEL LAPSE RATES...MLCAPES AROUND
1000-1500 J/KG ARE EXPECTED BY 20Z.
THIS AREA IS ON ERN EDGE OF MOST FAVORABLE DEEP-LAYER SHEAR -- 30-35
KT THROUGH 0-6 KM LAYER...BASED ON VWP AND RUC FCST PROFILES.  LOW
LEVEL HODOGRAPHS ARE NOT AS LARGE AS FARTHER E BECAUSE OF RELATIVELY
VEERED SFC FLOW AND WEAK BOUNDARY LAYER SPEEDS.  SEVERE POTENTIAL
MAY BE MORE LIMITED THAN IN WW 773 DUE TO SMALLER 0-1 KM SHEARS AND
WEAKER BUOYANCY...BUT SOME DAMAGING GUSTS AND HAIL STILL ARE
POSSIBLE...PARTICULARLY IN VA.

..EDWARDS.. 08/21/2004

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

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

37237685 36507746 35867818 35497911 35288121 35758174
37507916 38407779 38127669 37757640 

WWWW