Severe Thunderstorm Warning 121, NWS State College, PA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
214 PM EDT THU JUL 24 2008

.SYNOPSIS...

A SLOW MOVING COLD FRONT OVER EASTERN PENNSYLVANIA...WILL
CONTINUE OFF THE MID ATLANTIC COAST BY LATER TODAY AND OVERNIGHT.
MEANWHILE A STRONG DISTURBANCE ALOFT WILL CROSS PENNSYLVANIA THIS
AFTERNOON BRINGING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS.
IMPROVING CONDITIONS WILL OCCUR TONIGHT THROUGH FRIDAY NIGHT AS
HIGH PRESSURE BUILDS INTO THE REGION. ANOTHER COLD FRONT WILL
APPROACH THE REGION THIS WEEKEND WITH A ROUND OR TWO OF SHOWERS
AND THUNDERSTORMS ON SATURDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...

PRECIPITATION HAS TURNED DECIDEDLY CONVECTIVE WITH THE APPROACH OF
THE UPPER SHORTWAVE AND DAYTIME HEATING. TRACKING MARGINALLY
SEVERE CELLS NOW THRU CENTRAL MOUNTAINS...BIGGEST THREAT SEEMS TO
BE HAIL.

REST OF THE AFTERNOON WILL SEE THIS SHORTWAVE MOVE ESE INTO
PROGRESSIVELY MORE STABLE AIR...BUT WITH STEEP MID LEVEL LAPSE
RATES...WILL MAINTAIN THE THREAT FOR GUSTY WINDS AND HAIL FOR THE
NEXT FEW HOURS.

THINKING IS THAT CONDITIONS WILL IMPROVE RAPIDLY AFTER DARK AS THE
BEST OF THE INSTABILITY SHEARS OUT TO THE EAST AND WEAK HIGH
PRESSURE BUILDS IN OVER THE AREA. LIGHT WINDS AND CLEAR SKIES
COULD LEAD TO RATHER FOGGY START TO THE DAY TOMORROW. WILL PUT
AREAS OF FOG IN THE FORECAST FOR LATE NIGHT/EARLY
MORNING..ESPECIALLY OVER NORTHERN AREAS THAT SAW THE MOST RAIN
YESTERDAY AND ARE SEEING MORE TODAY.

A MUCH MORE COMFORTABLE NIGHT IS IN STORE FOR THE CWA AS
DEWPOINTS DECREASE INTO THE 50S AND SKIES BECOME PARTIALLY CLEAR.
TEMPERATURES WILL RANGE FROM THE UPPER 40S IN THE NORTHERN
MOUNTAINS TO THE MID 50S AND AROUND 60 IN CENTRAL AND SOUTHEASTERN
PENN RESPECTIVELY.

&&

.SHORT TERM /FRIDAY/...
FRIDAY SHOULD BE A DRY DAY WITH JUST SOME FAIR WEATHER CUMULUS
CLOUDS. EXPECT MORE SUNSHINE THAN ON THURSDAY AND SLIGHTLY WARMER
850MB TEMPS NEAR 13-14C. THIS SHOULD SUPPORT HIGHS ABOUT 5 DEGREES
WARMER THAN THURSDAY...JUST A DEG F OR SO BELOW NORMAL

OUR NEXT DISTURBANCE WILL APPROACH THE AREA FRIDAY NIGHT IN THE
FORM A SHORTWAVE EJECTING OUT OF THE PLAINS. THIS WILL LIKELY BE
ASSOCIATED WITH AN AREA OF SHOWERS AND THUNDERSTORMS WELL OFF TO
OUR WEST... BUT THEY SHOULD DISSIPATE BEFORE REACHING OUR
CWA...BRINGING MAINLY AN INCREASE IN MID TO HIGH CLOUDS DURING THE
MORNING. DRY CONDITIONS ARE EXPECTED THROUGH AT LEAST 10Z
SATURDAY. MINS EARLY SATURDAY WILL BE IN THE LOW/MID 60S ACROSS
THE CENTRAL AND SE (WHICH WILL BE ABOUT 5F WARMER THAN DAYBREAK
FRIDAY. LOWS ACROSS THE NW MTNS COULD BE AROUND 10F HIGHER THAN
FRIDAY...OR IN THE UPPER 50S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
AXIS OF MODERATELY HIGH SFC-850 HPA DEWPOINTS IS CHANNELED ENE
INTO OUR NRN AND WRN ZONES SATURDAY...AS THE LEFT EXIT REGION OF
NWRLY UPPER JET MOVES ACROSS NRN PENN. MAIN LARGER SCALE FORCING
AND LLVL INSTABILTY AXIS FOR SHRA/TSRA WILL BE ACROSS THE NW 1/3 OF
OUR CWA...WITH 30 PERCENT POPS PROBABLY PUSHING THE CHC FOR AN
AFTERNOON SHRA/TSRA ACROSS THE LOWER SUSQ VALLEY.

NOT A LOT OF CHANGE FROM YESTERDAY. REGARDING THE SECOND HALF OF
THE UPCOMING WEEKEND. DID EDGE POPS UP SOME FOR SUNDAY AND SUNDAY
NIGHT...AS THE UPPER LEVEL TROUGH MOVES ACROSS.

LEFT MONDAY AND TUE DRY...AND WENT WITH DRY CONDITIONS FOR
WED. EXPECT NW FLOW...AND NOT READY TO BUY INTO BLOW UP OF
FEATURE ON GFS.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...

ALL STATIONS HAVE GONE VFR WITH EXCEPTION OF BFD WHERE A SHOWER
HAS DRAGGED IN A MVFR CEILING. CONDITIONS SHUD REMAIN FAIR THRU
EVENING UNLESS THE SCATTERED THUNDERSTORMS PUSH THRU A TERMINAL.
IF THE CONVECTION MANAGES TO AFFECT AN AIRPORT...EXPECT
VISIBILITIES TO BRIEFLY DROP TO 1-3 MILES...WINDS GUST TO AROUND
40 MPH WITH THE POTENTIAL OF SOME HAIL TO NICKLE SIZE.

SKIES WILL SCATTER OUT EARLY IN THE EVENING...LEADING TO
DIMINISHING WINDS AND THE POTENTIAL FOR SOME LATE NIGHT FOG. OTHER
THAN THE THREAT OF FOG...BIGGEST WHEREVER IT MANAGES TO RAIN THIS
AFTERNOON AND EVENING...CONDITIONS WILL STAY FAIR THRU FRIDAY AS
HIGH PRESSURE DOMINATES.

ANOTHER FRONT MAY BRING A CHANCE OF THUNDERSTORMS ON SATURDAY
NIGHT INTO SUNDAY WITH HIGH PRESSURE TO FOLLOW FOR EARLY NEXT WEEK.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

SYNOPSIS...LACORTE
NEAR TERM...LACORTE
SHORT TERM...LAMBERT/CHENARD
LONG TERM...MARTIN
AVIATION...LACORTE

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
531 AM EDT THU JUL 24 2008

PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-049>053-
056>059-063>066-250945-
WARREN-MCKEAN-POTTER-ELK-CAMERON-NORTHERN CLINTON-CLEARFIELD-
NORTHERN CENTRE-SOUTHERN CENTRE-CAMBRIA-BLAIR-HUNTINGDON-MIFFLIN-
JUNIATA-SOMERSET-BEDFORD-FULTON-FRANKLIN-TIOGA-NORTHERN LYCOMING-
SULLIVAN-SOUTHERN CLINTON-SOUTHERN LYCOMING-UNION-SNYDER-MONTOUR-
NORTHUMBERLAND-COLUMBIA-PERRY-DAUPHIN-SCHUYLKILL-LEBANON-CUMBERLAND-
ADAMS-YORK-LANCASTER-
531 AM EDT THU JUL 24 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA.

.DAY ONE...TODAY AND TONIGHT

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

LAMBERT

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1242 PM EDT THU JUL 24 2008

PAZ010-241730-
ELK PA-
1242 PM EDT THU JUL 24 2008

...A STRONG THUNDERSTORM WILL AFFECT ELK COUNTY...

AT 1238 PM EDT...A STRONG THUNDERSTORM WAS LOCATED 8 MILES SOUTHWEST
OF KANE...MOVING SOUTHEAST AT 38 MPH.

WIND GUSTS TO 40 MPH AND PEA-SIZED HAIL ARE POSSIBLE WITH THIS STORM.

THIS STORM WILL BE NEAR ST. MARYS AROUND 100 PM AND FORCE AROUND 115
PM.

THIS WILL ALSO IMPACT THE FOLLOWING MAJOR ROADS...ROUTE 219...STATE
ROAD 66...STATE ROAD 120...STATE ROAD 255.

FORECASTER: LA CORTE

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
127 PM EDT THU JUL 24 2008

PAZ010>012-017-018-024-241800-
CAMBRIA PA-CAMERON PA-CLEARFIELD PA-ELK PA-NORTHERN CENTRE PA-
NORTHERN CLINTON PA-
127 PM EDT THU JUL 24 2008

...STRONG THUNDERSTORMS WILL AFFECT CLEARFIELD...NORTHEASTERN
CAMBRIA...SOUTHEASTERN ELK...SOUTHERN CAMERON...WEST CENTRAL CLINTON
AND WESTERN CENTRE COUNTIES...

AT 124 PM EDT...STRONG THUNDERSTORMS WERE ALONG A LINE FROM 17 MILES
EAST OF ST. MARYS TO 5 MILES SOUTHEAST OF PUNXSUTAWNEY...MOVING
SOUTHEAST AT 35 MPH.

WIND GUSTS TO 40 MPH AND HAIL UP TO DIME SIZE ARE POSSIBLE WITH THESE
STORMS.

THESE STORMS WILL BE NEAR KEATING AROUND 145 PM AND COALPORT AROUND
200 PM.

THIS WILL IMPACT THE FOLLOWING CENTRAL PENNSYLVANIA INTERSTATES...
I-80 BETWEEN MILE MARKERS 102 AND 136.

THIS WILL ALSO IMPACT THE FOLLOWING MAJOR ROADS...ROUTE 119...ROUTE
219...ROUTE 322...STATE ROAD 120...STATE ROAD 153...STATE ROAD 255.

FORECASTER: LA CORTE

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
153 PM EDT THU JUL 24 2008

PAZ018-019-241900-
NORTHERN CENTRE PA-SOUTHERN CENTRE PA-
153 PM EDT THU JUL 24 2008

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL CENTRE COUNTY...

AT 151 PM EDT...A STRONG THUNDERSTORM WAS LOCATED 10 MILES EAST OF
CLEARFIELD...MOVING EAST AT 28 MPH.

WIND GUSTS TO 50 MPH AND HAIL UP TO DIME SIZE ARE POSSIBLE WITH THIS
STORM.

THIS STORM WILL BE NEAR PHILIPSBURG AROUND 200 PM...MOSHANNON AROUND
215 PM...UNIONVILLE AROUND 230 PM...BELLEFONTE AROUND 245 PM AND
PLEASANT GAP AROUND 300 PM.

THIS WILL IMPACT THE FOLLOWING CENTRAL PENNSYLVANIA INTERSTATES...
I-80 BETWEEN MILE MARKERS 138 AND 167.

THIS WILL ALSO IMPACT THE FOLLOWING MAJOR ROADS...ROUTE 220...ALT
ROUTE 220...ROUTE 322...STATE ROAD 26.

FORECASTER: TYBURSKI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
236 PM EDT THU JUL 24 2008

PAZ018-024>026-241915-
BLAIR PA-CAMBRIA PA-HUNTINGDON PA-NORTHERN CENTRE PA-
236 PM EDT THU JUL 24 2008

...STRONG THUNDERSTORMS WILL AFFECT BLAIR...NORTHERN CAMBRIA...
NORTHERN HUNTINGDON AND SOUTHWESTERN CENTRE COUNTIES...

AT 233 PM EDT...STRONG THUNDERSTORMS WERE ALONG A LINE FROM TYRONE TO
11 MILES NORTHWEST OF ALTOONA TO EBENSBURG...MOVING SOUTHEAST AT 27
MPH.

WIND GUSTS TO 40 MPH AND SMALL HAIL ARE POSSIBLE WITH THESE STORMS.

THESE STORMS WILL BE NEAR TYRONE...TIPTON...AND LORETTO AROUND 245
PM...BELLWOOD AROUND 250 PM...TUNNELHILL...SINKING VALLEY...LILLY...
AND HORSESHOE CURVE AROUND 255 PM...SPRUCE CREEK AROUND 300 PM AND
FRANKLINVILLE AROUND 305 PM.

THIS WILL IMPACT THE FOLLOWING CENTRAL PENNSYLVANIA INTERSTATES...
I-99 BETWEEN MILE MARKERS 18 AND 52.

THIS WILL ALSO IMPACT THE FOLLOWING MAJOR ROADS...ROUTE 22...ROUTE
220...STATE ROAD 453.

FORECASTER: STEINBUGL

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
256 PM EDT THU JUL 24 2008

PAZ049-050-052-241945-
NORTHUMBERLAND PA-SNYDER PA-UNION PA-
256 PM EDT THU JUL 24 2008

...A STRONG THUNDERSTORM WILL AFFECT SNYDER...SOUTHWESTERN
NORTHUMBERLAND AND SOUTHWESTERN UNION COUNTIES...

AT 251 PM EDT...A STRONG THUNDERSTORM WAS LOCATED 11 MILES SOUTHWEST
OF MIFFLINBURG...MOVING SOUTHEAST AT 25 MPH.

WIND GUSTS TO 40 MPH AND SMALL HAIL ARE POSSIBLE WITH THIS STORM.

THIS STORM WILL BE NEAR BEAVERTOWN AROUND 310 PM...MIDDLEBURG AROUND
320 PM...FREEBURG AROUND 330 PM...HERNDON AROUND 340 PM AND RESLER
AROUND 350 PM.

THIS WILL ALSO IMPACT THE FOLLOWING MAJOR ROADS...ROUTE 11/15...ROUTE
522.

FORECASTER: STEINBUGL