Severe Thunderstorm Warning 183, NWS State College, PA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
955 AM EDT FRI JUL 14 2000

A COLD FRONT EXTENDS FROM THE SURFACE LOW LOCATED JUST NORTH OF LAKE
SUPERIOR.  THIS FRONT TRAILING SOUTH THROUGH ALPINA AND CHICAGO WILL
BE THE PRIMARY FOCUS FOR STRONG TO SEVERE STORMS THIS AFTERNOON.
LEAD UPPER SHORT WAVE NEAR SAGINAW BAY AND MID LEVER JET STREAK TO
ITS SOUTH IS SUPPORTING AN AREA OF THUNDERSTORMS ACROSS LAKE ERIE
AND SOUTHERN ONTARIO. THIS FEATURE IS EXTRAPOLATED TO NEAR KERI AT
18Z TODAY. COMBINATION OF LAKE ERIE BREEZE...OUTFLOW BOUNDARY FROM
THIS MORNINGS STORMS...AND SIGNIFICANT DESTABILIZATION OF THE LOW
LEVELS SHOULD LEAD TO A LINE OF THUNDERSTORMS INTENSIFYING BY EARLY
AFTERNOON OVER EXTREME WESTERN PA.

ETA SOUNDINGS ACROSS PENN INDICATE THAT MOST OF THE STORMS WILL BE
OF THE MULTICELL VARIETY. HWVR...COMBINATION OF MORE SIGNIFICANT
INSTABILITY AND MODERATE L/MID LVL VEERING WILL CREATE A MORE
CONDUCIVE ENVIRONMENT FOR  ROTATING UPDRAFTS ACROSS THE LWR SUSQ
VALLEY REGION LATE THIS AFTERNOON/EVENING.

AS A SECOND AND STRONGER SHORTWAVE DIGS SE ACROSS THE MID/UPR OHIO
VALLEY LATER TNGT AND SATURDAY THE FOCUS ACROSS CENTRAL PENN WILL
SHIFT TO HVY RAIN AND THE POTENTIAL FOR FLASH FLOODING. ETA
INDICATES THAT THE SFC FRONT AND CFA WILL BE NEARLY STALLED ACROSS
OUR ERN ZONES SAT AFTERNOON INTO EARLY SUNDAY. EXAMINATION OF MBE
VECTORS VIA BUFKIT SOFTWARE SUGGESTS THAT SLOW MOVING/TRAINING TSRA
WILL BE LIKELY ACROSS THE SUSQ VALLEY SAT INTO SUNDAY. 6 HOUR BASIN
AVG QPFS COULD EASILY EXCEED ONE INCH SAT AFTERNOON/NIGHT FROM IPT
TO MDT. CONSIDERING THAT THE EXPECTED REPEATING CELLS...HEAVIER RAIN
WONT OCCUR UNTIL SATURDAY AFTERNOON...I WILL LIKELY HOLD OFF ON THE
POSTING OF A FFA WITH THE LATE AFTERNOON PACKAGE FOR THE ABOVE
REGION...AND LET THE LATER SHIFTS HANDLE IT.

FURTHER WEST ACROSS THE AREA...COLD TEMSP ALOFT AND FAIRLY WELL
ALIGNED WNW FLOW ALOFT WILL PROMOTE MORE SCATTERED/LOWER TOPS
SHRA/TSTMS DURING THE LATER PERIODS OF THE FCST.

WILL MAKE SOME MINOR MODIFICATIONS TO TEMPS AND CLOUD COVER ACROSS
THE FCST AREA FOR THE LATE MORNING UPDATE...OTHERWISE POPS IN THE
LIKELY CATEG LOOK GREAT FOR THIS AFTERNOON.

.CTP...NONE.

LAMBERT/SEILHAMER

PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-049>053-
056>059-063>066-142200-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1140 AM EDT FRI JUL 14 2000

...THERE IS MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING ACROSS WESTERN PENNSYLVANIA...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
REMAINDER OF CENTRAL PENNSYLVANIA AND THE SUSQUEHANNA VALLEY THIS
AFTERNOON THROUGH THIS EVENING...

...LOCALLY HEAVY RAINFALL IS ALSO LIKELY TONIGHT THROUGH SATURDAY...

A COLD FRONT MOVING SOUTHEAST FROM THE GREAT LAKES REGION WILL
TRIGGER NUMEROUS THUNDERSTORMS ACROSS CENTRAL PENNSYLVANIA THIS
AFTERNOON AND THIS EVENING. A FEW THUNDERSTORMS MAY BECOME
SEVERE...PRODUCING LOCALIZED WIND GUSTS AROUND OR OVER 60 MPH...OR
LARGE HAIL.

A LINE OF THUNDERSTORMS IS EXPECTED TO INTENSIFY EARLY THIS
AFTERNOON ACROSS EXTREME NORTHWEST PENNSYLVANIA...ALONG THE LEADING
EDGE OF THE LAKE ERIE BREEZE. THESE STORMS WILL THEN MOVE STEADILY
SOUTHEASTWARD AND AFFECT THE CENTRAL THIRD OF THE STATE DURING THE
MID AND LATE AFTERNOON.

THROUGHOUT THE SUSQUEHANNA VALLEY...THE STRONGER THUNDERSTORMS WILL
FORM...OR MOVE INTO THE REGION FROM THE NORTHWEST LATER THIS
AFTERNOON...AND LIKELY CONTINUE THROUGH THIS EVENING.

SHOWERS AND THUNDERSTORMS WILL CONTINUE IN MANY AREAS THROUGH
TONIGHT...WITH LOCALIZED HEAVY RAINFALL LIKELY. HOWEVER...THE RISK
OF STRONG WINDS OR LARGE HAIL WILL DECREASE AFTER MIDNIGHT.

SHOWERS AND THUNDERSTORMS WILL REMAIN LIKELY SATURDAY THROUGH
SATURDAY NIGHT...WITH THE POTENTIAL FOR LOCALLY HEAVY RAIN
CONTINUING...ESPECIALLY ACROSS THE SUSQUEHANNA VALLEY AND SOUTH
CENTRAL PENNSYLVANIA.

SKYWARN SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON OR THIS
EVENING.

LAMBERT