Severe Thunderstorm Warning 28, NWS State College, PA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
155 PM EDT WED MAY 24 1995

...THUNDERSTORMS OVER WRN PA LATE THIS AFTN/EVE...

THIS AFTERNOONS RADAR SHOWS DEEP LAYER OF MOISTURE AND CLOUDS.
PICKING UP WINDS FROM SFC TO 10 KFT.  MOST SIGNIFICANT RADAR
RETURNS IN SWRN NY THIS AFTERNOON.  RAMSDIS SHOWS LINES OF CLOUDS
OVER ALLEGHENY FRONT AND THE RIDGE LINES OF CENTRAL PA. MOSTLY
CIRRUS OVER NWRN PA.  DESPITE SMALL CONVECTIVE ELEMENTS IT WILL
BE SOMETIME BEFORE ANYTHING ORGANIZED CAN GET GOING.

GRIDDED DATA SHOWS GOOD INSTABILITY AND WEAK LL FORCING IN THE
FORM OF CONV AT 1000/850 MB.  ISENTROPIC SFCS GOOD INFLOW OF HIGH
MIX RATIO AIR OVER PA FROM SW TO E.  THIS IS ORIENTED CLOSELY
WITH THE 850 MB THETA-E PATTERN.  BEST ISENTROPIC LIFT IS ON I300
AND I302 SFCS WITH MAXIMA IN PA OVER NWRN SECTIONS.  THE ETA
KEEPS MOST OF THIS LIFT ACROSS NWRN PA AND THE SRN TIER OF NY.
THE BEST INSTABILITY IS OVER CENTRAL PA.  VIRTUALLY ALL THE MODEL
PCPN IS CONVECTIVE OVER THE STATE.

BEST CHANCE POPS SHOULD BE OVERNIGHT AS FRONT SAGS INTO AREA.
THE LIFT DECREASES AFT 12Z THURS BUT THE INSTABILITY AND FRONT
REMAIN IN THE AREA DURING THE DAY THURS.  MODELS SHOW GOOD CONV
NEAR THE LL BOUNDARY SUGGESTING SHOWERS/TSTMS THROUGH THE DAY
THURS.  SUBSIDENCE AND CAA SWEEP ACROSS REGION THURS EVE INTO
EARLY FRI.  RAPID CLEARING AND DRYING THURS NIGHT.

GRUMM