[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 121659
SWOMCD
SPC MCD 121659 
NCZ000-VAZ000-SCZ000-TNZ000-121930-

MESOSCALE DISCUSSION 0838
NWS STORM PREDICTION CENTER NORMAN OK
1159 AM CDT THU MAY 12 2005

AREAS AFFECTED...SRN VA...NC...AND FAR NRN SC

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 121659Z - 121930Z

SCATTERED THUNDERSTORM DEVELOPMENT IS ANTICIPATED THIS AFTERNOON
ACROSS FAR SRN VA...NC...AND FAR NRN SC. STORM ORGANIZATION SHOULD
BE LIMITED BY WEAK DEEP-LAYER SHEAR. HOWEVER...A FEW SEVERE CELLS OR
MULTICELLULAR CLUSTERS WITH LOCALLY DAMAGING WINDS OR ISOLATED LARGE
HAIL ARE POSSIBLE. WW IS NOT ANTICIPATED AT THIS TIME.

MUCH OF SRN VA/NC/NRN SC CONTINUES TO HEAT STRONGLY EARLY THIS
AFTERNOON /TEMPERATURES IN THE LOW TO MID 80S/ WITH GENERALLY CLEAR
SKIES PRESENT. DISCUSSION AREA IS SITUATED ON NERN PERIPHERY OF
MID-LEVEL RIDGE ACROSS THE CENTRAL GULF STATES.
AT THE SURFACE...A WEAK WIND SHIFT/PRE-FRONTAL TROUGH EXTENDS E-W
ACROSS CENTRAL NC. THE SYNOPTIC COLD FRONT WILL CONTINUE TO MOVE SWD
FROM CENTRAL VA AND THE DELMARVA PENINSULA...IN RESPONSE TO STRONG
COLD AIR ADVECTION AND AN UNSEASONABLY STRONG SURFACE ANTICYCLONE
ACROSS ONTARIO CANADA. SURFACE DEWPOINTS INITIALLY IN THE LOW 60S
EARLY THIS AFTERNOON WILL LIKELY MIX DOWN INTO THE MID 50S ACROSS
MOST OF THE REGION AS BOUNDARY LAYER DEEPENS. THIS WILL HELP
ESTABLISH SURFACE DEWPOINT DEPRESSIONS OF 30-35F.

SEVERE THREAT TODAY WILL BE PRIMARILY DRIVEN BY INSTABILITY AND THE
POTENTIAL FOR STRONG CONVECTIVE DOWNDRAFTS WITH STRONGER CORES.
MLCAPE VALUES ARE EXPECTED TO PEAK OUT AROUND 1500 J/KG.
DEEP-LAYER SHEAR IS MARGINAL FOR ORGANIZED STORMS /SFC-6KM SHEAR IS
NWLY AT 20-30KT/. IT IS POSSIBLE THAT MESOSCALE OUTFLOW BOUNDARIES
MAY ALLOW FOR A COUPLE OF SWD OR SEWD MOVING BANDS OF STORMS DURING
THEIR EVOLUTION THROUGH LATE AFTERNOON/EARLY EVENING. THE
PRE-FRONTAL TROUGH AND APPROACHING COLD FRONT SHOULD PROVIDE A FOCUS
FOR LOW-LEVEL CONVERGENCE SUFFICIENT FOR INITIATION DURING THE NEXT
FEW HOURS. SEPARATE TOWERING CU ALONG THE EAST SLOPES OF THE
APPALACHIANS MAY ALSO RESULT IN ISOLATED THUNDERSTORMS THAT TRACK
SEWD. ENVIRONMENT SUGGESTS LOCALIZED DAMAGING WIND POTENTIAL...AS
WELL AS MARGINALLY SEVERE HAIL WITH STRONGER CELLS.

..BANACOS.. 05/12/2005

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

ATTN...WFO...AKQ...MHX...RAH...ILM...RNK...CAE...GSP...MRX...

36747774 36507733 36037707 35557706 34987732 34647765
34567903 34658119 34728271 35008308 35278384 35628319
36078212 36988112 37258054 37317999 36827903 36747828 

WWWW