Severe Thunderstorm Warning 25, NWS State College, PA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
930 AM EDT MON JUL 07 2003

SENT UPDATE TO REGROUP ZONES AND GO LIKELY POPS WHERE IT IS
CURRENTLY RAINING...NORTHWEST.

CURRENT RUC ANALYSIS AND FCST SHOW THAT NORTHERN OHIO/NORTHWEST PA
SHOULD BE CONVECTIVE INITIALIZATION AREA TODAY AS FAVORABLE AREA OF
JET MAX...LLJ...THETA-E RIDGE AND NICE DRY SLOT IN CLOUDS ALL COME
TOGETHER OVER THAT AREA. THETA-E PACKING AND LLJ FCST TO BE RATHER
WEAK OVER SOUTHEAST PA SO ISOLATED PULSE STUFF A BETTER BET. CHANCE
POPS THERE. SUMMERS HERE....

DIRIENZO

---PREVIOUS AFD---

OVERALL: WARM AND MUGGY CONDITIONS TO PREVAIL THROUGH MIDWEEK WITH
SHOWER AND THUNDERSTORM CHANCES EACH DAY AS SHORTWAVE TRAIN
CONTINUES. COLD FRONT ARRIVES WEDNESDAY WITH MORE SHOWERS AND
STORMS. SOME LOWER DEWPOINTS SEEP SOUTHWARD BEHIND THE FRONT...BUT
BOUNDARY STALLS NEAR OR JUST SOUTH OF THE MASON DIXON LINE AND
RETURNS NORTHWARD THURSDAY...AHEAD OF STORM SYSTEM ARRIVING FROM THE
UPPER MIDWEST WHICH SHOULD BRING WIDESPREAD SHOWERS AND
THUNDERSTORMS TO CENTRAL PA THU-FRI.  LATEST GFS/ECMWF DEPICT A COLD
SEASON-TYPE COASTAL CYCLOGENESIS OFF THE DELMARVA WITH SFC LOW
TRACKING UP THE NEW ENGLAND COASTLINE AS UPPER SYSTEM GOES NEGATIVE
TILT...HARD TO BELIEVE BUT LAST FEW RUNS HAVE BEEN CONSISTENT IN THE
INTENSITY OF THE LATE WEEK SYSTEM.

SHORTER TERM CONCERNS:  CONVECTION OVER OHIO VALLEY HAS BEEN SLOW
MOVING WITH LOCALLY HEAVY RAINFALL. NICE SHORTWAVE CIRCULATION
EVIDENT OVR MI THIS MORNING WITH JUICY AIR MASS TO FEED ON OVER THE
EASTERN OHIO VALLEY...AND EXPECT SCATTERED SHOWERS AND THUNDERSTORMS
TO AFFECT CENTRAL AND WESTERN PORTIONS OF CENTRAL PA FOR MOST OF THE
DAY...AFFECTING SOUTHEAST SECTIONS MAINLY LATE MORNING AND AFTERNOON
HOURS.  SLOW MOVING SHORTWAVE EXITS TO OUR NORTHEAST THIS EVENING
WITH ANOTHER ONE FOLLOWING IN ITS WAKE AND ANOTHER SURGE OF DEEP
LAYER MOISTURE AS PWS INCREASE TO OVER 1.5 OVER WESTERN PA.  YET
ANOTHER 5H TROF REACHE NW PA TUESDAY NIGHT WITH MCS DEVELOPING OVER
OHIO AND MOVING INTO SOUTHERN AND WESTERN PA...AHEAD OF MAIN FRONTAL
SYSTEM WHICH EVENTUALLY SAGS SOUTHWARD ACROSS THE AREA.  ANOTHER
ROUND OF LOCALLY HEAVY RAIN IS LIKELY WEDNESDAY FROM THIS SCENARIO.

BOUNDARY GOES STATIONARY WEDNESDAY NIGHT AND RETURNS NORTHWARD AS
WARM FRONT LATER THURSDAY. PRIOR TO THAT...WED NGT THROUGH MIDDAY
THURSDAY LOOKS LIKE THE DRIEST PERIOD OF THE WEEK...BUT MOISTURE
RETURNS WITH A VENGEANCE IN THE RETURN FLOW AND AN ANOMALOUSLY
STRONG WAVE MOVES ALONG THE FRONT THU NIGHT AND FRIDAY...WITH A
SECONDARY STORM DEVELOPING ALONG THE DEL MARVA AND THEN TRACKING
NORTH/NORTHEAST.  GOOD NEWS WITH THIS SCENARIO IS THAT DRIER
NORTHWEST FLOW WILL ULTIMATELY PREVAIL BY THE WEEKEND...AND IT LOOKS
LIKE A DRY ONE AFTER A RATHER WET WEEK.

ISC GRIDS/WORK ZONES SENT.

FCSTID =    07
MDT   90  71  94  71 /  50  20  30  30
IPT   89  70  90  69 /  50  50  60  40
BFD   82  66  81  63 /  40  50  60  50
JST   83  66  81  63 /  40  30  60  50
AOO   86  68  85  66 /  40  30  60  50
UNV   88  69  88  68 /  40  40  60  50
SEG   89  71  90  70 /  50  40  50  40
LNS   90  71  93  71 /  50  20  30  30
THV   90  71  92  70 /  40  20  30  30

.CTP...
PA...NONE.

DEVOIR

PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-049>053-
056>059-063>066-071100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
500 AM EDT MON JUL 7 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA.

.DAY ONE...TODAY

SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED ONCE AGAIN TODAY.
THE STORMS COULD BE LOCALLY SEVERE...WITH STRONG WIND GUSTS THE MAIN
SEVERE WEATHER THREAT.  SLOW MOVING THUNDERSTORMS MAY ALSO PRODUCE
TORRENTIAL RAINFALL LEADING TO LOCAL DRAINAGE PROBLEMS.

.DAYS TWO THROUGH SEVEN...

ADDITIONAL SHOWER AND THUNDERSTORM ACTIVITY WILL BE POSSIBLE ON
TUESDAY...AND SOME OF THESE STORMS COULD ONCE AGAIN BE STRONG TO
LOCALLY SEVERE.  A COLD FRONT WILL DROP ACROSS THE AREA WEDNESDAY
AFTERNOON AND NIGHT...BRINGING THE CHANCE FOR MORE LOCALLY STRONG
THUNDERSTORMS. COOLER AND LESS HUMID AIR WILL BRIEFLY ARRIVE IN ITS
WAKE ON THURSDAY...BEFORE THE FRONT MOVES BACK NORTH AS A WARM FRONT
SIGNALLING ADDITIONAL SHOWER AND THUNDERSTORM ACTIVITY THURSDAY
NIGHT INTO FRIDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED.

DEVOIR

PAZ018-019-071715-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1148 AM EDT MON JUL 7 2003

...A STRONG THUNDERSTORM WILL AFFECT CENTRE COUNTY THROUGH 115 PM...

AT 1145 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 9 MILES NORTH OF TYRONE...MOVING EAST AT 25 MPH.
THE THUNDERSTORM WILL BE NEAR PORT MATILDA AROUND 1205 PM...PARK
FOREST AROUND 1225 PM...UNIONVILLE AND STATE COLLEGE AROUND 1230
PM...PLEASANT GAP...BELLEFONTE AROUND 1245 PM...CENTRE HALL AROUND
1250 PM AND ZION AROUND 1255 PM.

WIND GUSTS TO 50 MPH AND SMALL HAIL ARE POSSIBLE WITH THIS STORM.

BETWEEN ONE HALF INCH...AND ONE INCH OF RAIN IS ALSO LIKELY NEAR AND
JUST TO THE SOUTH OF INTERSTATE 80.

EXPECT INTENSE LIGHTNING FROM THIS STORM. DO NOT SEEK SHELTER UNDER
TREES OR STAY IN THE OPEN WHEN LIGHTNING THREATENS. STAY INDOORS AND
AWAY FROM WINDOWS UNTIL THE STORM HAS PASSED.

LAMBERT/BLEISTEIN

PAZ012-019-027-028-036-037-041-042-045-046-049>053-056>059-063>066-
071900-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1257 PM EDT MON JUL 7 2003

...STRONG THUNDERSTORMS WILL AFFECT PARTS OF CENTRAL PENNSYLVANIA...
AND MUCH OF THE SUSQUEHANNA VALLEY THIS AFTERNOON...

AT 1251 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
AREA OF HEAVY SHOWERS AND EMBEDDED THUNDERSTORMS FROM STATE COLLEGE
AND RENOVO...EAST TO LOCK HAVEN...MILLHEIM AND MCCLURE. ADDITIONAL
THUNDERSTORMS WERE DEVELOPING IN A LINE BOTH TO THE NORTH AND SOUTH
OF THIS MAIN AREA OF RAIN.

THE SHOWERS AND STORMS WERE MOVING TO THE EAST AT 25 MPH.

THE THUNDERSTORMS WILL INTENSIFY DURING THE MID AFTERNOON AS THEY
MOVE INTO THE VERY WARM AND HUMID AIRMASS IN PLACE ACROSS THE
SUSQUEHANNA VALLEY.

VERY HEAVY RAIN OF ONE INCH IN 30 MINUTES WILL FALL IN SOME
LOCATIONS ...AND POSSIBLY CAUSE WATER TO POND ON ROADS AND QUICKLY
FILL ROADSIDE DITCHES AND SMALL STREAMS.

WIND GUSTS TO 50 MPH AND SMALL HAIL ARE POSSIBLE WITH THE STORMS
ACROSS THE SUSQUEHANNA VALLEY.

SEEK SHELTER INDOORS AND AWAY FROM WINDOWS AS THE STORMS APPROACH.

LAMBERT/BLEISTEIN