Severe Thunderstorm Warning 134, NWS State College, PA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
925 AM EDT THU JUN 15 2000

BIG DIFFERENCE BETWEEN YESTERDAY AND TODAY AS FAR AS CONVECTIVE
INITIATION GOES. WE HAVE A LARGE SCALE DYNAMIC TRIGGER TODAY...THIS
IN THE FORM OF A LIFTING 250 MB JET MAX OVER ONTARIO. MANY
ATMOSPHERIC CHARACTERISTICS ARE NEARLY IDENTICAL TO YESTERDAY
HOWEVER...INCLUDING LOCATION OF STATIONARY BOUNDARY BISECTING OUR FORECAST
AREA OF RESPONSIBILITY AND HIGH INSTABILITY (MODEL CAPES OF 1500 TO
2500 J/KG OVER CENTRAL AND WESTERN PA). RIGHT ENTRANCE REGION OF
THIS JET WILL PROPOGATE ACROSS WESTERN AND NORTHERN SECTIONS BY LATE
MORNING SIGNALLING CONVECTIVE INITIATION. CONVECTIVE TEMPS AROUND
80.

INCREASE IN VERTICAL WIND SHEAR FROM UPPER JET...850 MB WINDS
INCREASING TO AROUND 30 KTS... AND 500 MB WINDS INCREASING TO 45 TO
50 KTS INDICATE SOME POTENTIAL FOR DAMAGING WINDS WITH TODAYS
STORMS. STORM RELATIVE HELICITY VALUES APPROACHING 140 (M)2/(S)2
SUGGESTS POTENTIAL FOR ROTATING STORMS.  00 UTC ETA INDICATES BEST
MOISTURE CONVERGENCE PROPOGATING ACROSS THE AREA FROM 18 UTC TO 00
UTC...ALONG WITH IMPRESSIVE 700 MB OMEGA (SOME CONVECTIVE FEEDBACK
MAY BE SHOWING UP HERE).

AT ANY RATE...POTENTIAL EXISTS FOR SOME SEVERE WEATHER...AGAIN THE
PARAMETERS ARE MARGINAL BUT GIVEN PLENTY OF INSTABILITY AND NOW
MODERATE SHEAR...THIS SHOULD BE AN ACTIVE AFTERNOON.

AGREE WITH PREVIOUS SHIFTS ASSERTION THAT STATIONARY FROM SHOULD
FINALLY MAKE A JUMP TO THE EAST TODAY.  TIMING OF STRATUS SCOURING
STILL A PROBLEM AND WILL SOMEWHAT PUT A DAMPER ON STORMS EAST OF
STATE COLLEGE TODAY. MAIN SEVERE THREAT REMAINS WEST OF STATE
COLLEGE THIS AFTERNOON.

GOING FORECAST HAS ALL NECESSARY DETAILS IN PLACE.  WILL CLEAN UP
MORNING WORDING AND MAKE SURE TEMPERATURES ARE BEHAVING BEFORE
SENDING ZONES BY 1030 AM.

PHLADMCTP TO BE SENT BY 1000 AM EDT.

.CTP...SPS FOR POTENTIAL SEVERE TSRA (SLIGHT RISK).

DEVOIR

PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-049>053-
056>059-063>066-151500-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1100 AM EDT THU JUN 15 2000

...THE STORM PREDICTION CENTER INDICATES A SLIGHT RISK OF SEVERE
THUNDERSTORMS THIS AFTERNOON AND EVENING OVER CENTRAL PENNSYLVANIA...

AN UPPER LEVEL DISTURBANCE LIFTING INTO SOUTHERN ONTARIO WILL
COMBINE WITH MOIST AND UNSTABLE AIR TO PRODUCE SHOWERS AND
THUNDERSTORMS OVER CENTRAL PENNSYLVANIA THIS AFTERNOON. THE
POTENTIAL EXISTS FOR GUSTY AND POSSIBLY DAMAGING WIND GUSTS AND
LARGE HAIL WITH THUNDERSTORMS THIS AFTERNOON AND EVENING. LOCAL
HEAVY RAIN IS ALSO EXPECTED.

SKYWARN ACTIVATION MAY BE NEEDED TODAY.

DEVOIR