MESO: Mesoscale Discussion 1292

ACUS11 KWNS 281931
SWOMCD
SPC MCD 281930
NJZ000-PAZ000-DEZ000-MDZ000-DCZ000-VAZ000-WVZ000-OHZ000-282130-

MESOSCALE DISCUSSION 1292
NWS STORM PREDICTION CENTER NORMAN OK
0230 PM CDT FRI JUN 28 2013

AREAS AFFECTED...PORTIONS ERN OH...PA...WV...MD...DC...NRN
VA...DE...NJ.

CONCERNING...SEVERE THUNDERSTORM WATCH 386...387...

VALID 281930Z - 282130Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
386...387...CONTINUES.

SUMMARY...CONTINUE WWS. WW 386 IS BEING EXTENDED SOMEWHAT NWD
ACROSS PORTIONS ERN OH AND WRN PA PER COORD W/WFO PBZ. THOUGH
PORTIONS WW 386 ACROSS SWRN PA AND EXTREME NRN WV HAVE BEEN
STABILIZED FOR NOW BY PRIMARY TSTM BAND...ADDITIONAL CONVECTION OVER
OH MAY POSE AT LEAST MRGL SVR RISK OVER WRN PORTIONS WW AS IT MOVES
INTO MODIFYING AIR MASS. MEANWHILE SVR POTENTIAL WILL CONTINUE WITH
CONVECTION FROM THERE EWD TO ATLC COAST.

DISCUSSION...BAND OF STG-SVR TSTMS ACROSS SWRN PA...GARRETT COUNTY
MD AND NERN WV IS MOVING THROUGH RELATIVE MOISTURE MIN ATTM...BUT
WILL ENCOUNTER SUBSTANTIALLY RICHER THETAE OVER ERN MTNS AND
ADJOINING PIEDMONT. SEVERAL REPORTS OF TOPPLED TREES HAVE BEEN
RECEIVED FROM PASSAGE OF THESE TSTMS. FURTHER INTENSIFICATION OF
THIS ACTIVITY IS POSSIBLE...AS IS CONTINUED SVR THREAT WITH MORE
WIDELY SCATTERED BLEND OF DISCRETE AND CLUSTERED CONVECTIVE MODES
FARTHER E TOWARD DE VALLEY AND CHESAPEAKE BAY REGIONS. UPSCALE
AGGREGATION OF COLD POOLS IS POSSIBLE FROM ANY OF THIS
ACTIVITY...ENHANCING POTENTIAL FOR FORWARD-PROPAGATIONAL DAMAGING
WIND ON MESOBETA SCALE.

SOME SUPERCELL RISK ALSO EXISTS...PRIMARILY FROM EXTREME SRN PA SWD
ACROSS ERN WV PANHANDLE AND MD INTO NRN VA...THEN SHIFTING EWD OVER
DELMARVA/NJ. THAT AREA LIES BENEATH ENHANCED BELT OF MID-UPPER
LEVEL FLOW THAT OFFSETS VEERED BOUNDARY LAYER WINDS ENOUGH TO
GENERATE 40-50 KT EFFECTIVE SHEAR MAGNITUDES. PRECONVECTIVE AIR
MASS SHOULD REMAIN FAVORABLY UNSTABLE FOR NEXT FEW HOURS...WITH SFC
DEW POINTS 70S F IN LOWER ELEVATIONS AND INSOLATION CONTRIBUTING TO
MLCAPE 1500-2500 J/KG E OF BLUE RIDGE. 1000-1500 J/KG MLCAPE IS
EVIDENT OVER HIGHER TERRAIN AND WWD INTO ERN OH.

..EDWARDS.. 06/28/2013

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

ATTN...WFO...PHI...AKQ...CTP...LWX...PBZ...RLX...CLE...

LAT...LON 38437497 38297913 38418179 40498181 40998061 41227941
41167698 40577512 39967405 38957481 38437497

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.