Severe Thunderstorm Warning 106, NWS State College, PA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
915 AM EDT TUE JUL 23 2002

QUICK UPDATE TO ACCOUNT FOR CLOUD/TEMP OBSERVATIONS. NEW GUIDANCE
FROM SPC HAS A LARGER PART OF CWA IN SLIGHT RISK SO WILL TINT
WORDING TOWARDS STRONG STORMS FOR CENTRAL AREAS AS WELL. NO CHANGES
LATER PERIODS.

DIRIENZO

...PREVIOUS AFD...

AS OF 08Z...REGIONAL RADAR SHOWING A BROKEN LINE OF SHOWERS AND
STORMS WITH CDFRONT CROSSING LK ERIE. EXPECT RADAR TO FILL IN LATER
TODAY AS FRONT MOVES INTO VERY WARM AND UNSTABLE AIRMASS OVER
CENTRAL PA. DWPTS ALREADY NEAR 70F AND IR IMAGERY SUGGESTS A GOOD
DEAL OF MORNING SUNSHINE FOR EASTERN SECTIONS...WHICH SHOULD PUSH
TEMPS OVER 90F ONCE AGAIN FROM MDT SOUTH. INSTABILITY APPEARS GREAT
ENOUGH FOR ISOLATED SVR TODAY. HOWEVER...BIGGER THREAT MAY BE
LOCALLY HEAVY RAINFALL...DUE TO HIGH PRECIPITABLE WATER VALUES AND
WEAK MID-UPPER LVL FLOW.

FRONT SAGS SOUTH TONIGHT...BRINGING AND END TO SHOWERS/STORMS IN THE
SOUTH...AND CLEARING SKIES FURTHER NORTH. SFC HIGH PRES THEN PASSES
TO OUR NORTH FOR MID WEEK...BRINGING CLEARING AND DRIER CONDITIONS
TO PA...WHILE HEAT AND HUMIDITY REMAIN JUST TO THE SOUTH. MODEL
ENSEMBLE DATA SUGGESTING A CHANCE OF RAIN THURSDAY NIGHT AND FRIDAY
AS WAVE OF LOW PRES RIDES EASTWARD ALONG FRONT...STILL LYING JUST TO
OUR SOUTH ACROSS N VIRGINIA.

MED RANGE ENSEMBLE DATA SUGGESTS WARM AND HUMID WX RETURNS OVER THE
WEEKEND WITH SW FLOW AND 850 TEMPS BACK TO ARND 17C.

.CTP...SPS FOR POSSIBLE SEVERE STORMS LOWER SUSQ VALLEY.

FITZGERALD

PAZ012-017>019-024>028-033>037-041-042-045-046-049>053-056>059-
063>066-232230-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1133 AM EDT TUE JUL 23 2002

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING ACROSS MOST OF CENTRAL PENNSYLVANIA AND ADJACENT PORTIONS OF
THE SUSQUEHANNA VALLEY.

A STRONG COLD FRONT...MOVING THROUGH EXTREME NORTHWEST PENNSYLVANIA
AT NOON WILL PUSH INTO SOUTHEASTERN PENNSYLVANIA THIS EVENING.

SHOWERS AND THUNDERSTORMS WILL STRENGTHEN ALONG AND AHEAD OF THE
FRONT IN THE HOT AND HUMID AIRMASS...AND SOME OF THESE STORMS COULD
BECOME SEVERE. THE GREATEST RISK FOR LOCALIZED DAMAGING WIND GUSTS
AROUND 60 MPH...AND HAIL IS BETWEEN THE HOURS OF 2 PM AND 5 PM
ACROSS THE CENTRAL AND NORTHERN MOUNTAINS...AND FROM 4 TO 8 PM
OVER THE CENTRAL AND LOWER SUSQUEHANNA VALLEY.

ANOTHER CONCERN WILL BE LOCALLY VERY HEAVY RAINFALL AMOUNTS...SINCE
THE THUNDERSTORMS WILL BE RATHER SLOW MOVING. SIGNIFICANT PONDING
AND PERHAPS MINOR FLOODING OF SMALL STREAMS AND CREEKS COULD
OCCUR...ESPECIALLY WHERE SEVERAL STORMS MOVE OVER THE SAME AREA AND
DUMP UP TO 2 INCHES WITHIN AN HOUR OR SO. .

STAY TUNED TO NOAA WEATHER RADIO AND OTHER LOCAL MEDIA FOR FURTHER
DETAILS OR UPDATES.

LAMBERT/MCPHEE