[MCD] SWOMCD

Wed Jul 12 15:56:29 UTC 2006

ACUS11 KWNS 121556
SWOMCD
SPC MCD 121555 
CTZ000-NYZ000-NJZ000-PAZ000-DEZ000-MDZ000-121730-

MESOSCALE DISCUSSION 1483
NWS STORM PREDICTION CENTER NORMAN OK
1055 AM CDT WED JUL 12 2006

AREAS AFFECTED...ERN PA / NJ / SERN NY

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 121555Z - 121730Z

THE POTENTIAL FOR SEVERE TSTMS INCLUDING SUPERCELLS CAPABLE OF A FEW
TORNADOES IS EXPECTED TO INCREASE ACROSS DISCUSSION AREA THIS
AFTERNOON.  CONVECTIVE TRENDS WILL BE MONITORED FOR A WW ISSUANCE.

COMPLEX SURFACE PATTERN EXISTS LATE THIS MORNING OWING TO
ONGOING...WIDESPREAD PRECIPITATION.  MAIN SURFACE LOW OVER SWRN
ONTARIO IS FORECAST TO DEVELOP NEWD ALONG BAROCLINIC ZONE THROUGH
LAKE ONTARIO THIS AFTERNOON.  FARTHER TO THE SE...DIFFERENTIAL
HEATING ZONE/OUTFLOW BOUNDARY ANALYZED FROM NEAR AVP TO S OF POU HAS
STARTED TO LIFT SLOWLY NWD IN RESPONSE TO INCREASING PRESSURE FALLS
OVER UPSTATE NY.  MEANWHILE TO THE S OF THIS BOUNDARY...BREAKS IN
THE CLOUDS HAVE ALLOWED FOR LOCALLY STRONGER DIABATIC HEATING OVER
ERN PA AND NJ WHERE TEMPERATURES HAVE WARMED INTO THE LOWER/MID 80S.
WHEN COUPLED WITH VERY MOIST BOUNDARY LAYER CONDITIONS /70-75 F
DEWPOINTS/ AIR MASS IS ALREADY MODERATELY UNSTABLE WITH SBCAPES OF
1000-2000 J/KG AND LITTLE OR NO CAP.

TSTMS ARE EXPECTED TO BECOME INCREASINGLY NUMEROUS WITHIN THIS
CORRIDOR OF STRONGER INSTABILITY THIS AFTERNOON WITH THE GREATEST
SEVERE WEATHER POTENTIAL APPEARING TO EXIST ALONG RETREATING OUTFLOW
BOUNDARY OVER NERN PA INTO SERN NY.  HERE...LOCALLY STRONGER
LOW-LEVEL SHEAR /0-1 KM SRH OF 100-200 M2/S2/ WILL BE SUPPORTIVE OF
SUPERCELLS CAPABLE OF A FEW TORNADOES GIVEN THE VERY MOIST LOW-LEVEL
ENVIRONMENT.  BOTH DEEP AND LOW-LEVEL SHEAR WILL TEND TO DECREASE
WITH SWD EXTENT OVER ERN PA AND NJ...HOWEVER THE STRONGEST STORMS
WILL REMAIN CAPABLE OF LOCALLY DAMAGING WINDS.

..MEAD.. 07/12/2006

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

ATTN...WFO...OKX...ALY...PHI...BGM...CTP...LWX...

39887722 40877695 41587644 41967596 42117535 41987445
41707376 41057362 39877408 39407482 39297646 

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