Severe Thunderstorm Warning 70, NWS State College, PA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1152 AM EDT THU MAY 19 2011

.SYNOPSIS...
A DEEP UPPER LEVEL CIRCULATION OVER THE UPPER OHIO VALLEY WILL
MOVE VERY SLOWLY EASTWARD TODAY ACROSS PENNSYLVANIA AND OUT TO
SEA BY SATURDAY. MODERATING TEMPERATURES AND A PERIOD OF MAINLY
DRY WEATHER APPEAR IN STORE FOR THE WEEKEND...AS AN UPPER LEVEL
RIDGE OF HIGH PRESSURE BUILDS EASTWARD FROM THE MIDWEST. ABOVE
NORMAL TEMPERATURES ARE POSSIBLE BY EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
LOW TOPPED CONVECTION HAS REDEVELOPED OVER THE HIGHER TERRAIN OF
SOUTH CENTRAL MTNS AND LOWER TO MID SUSQ AND IS TRAINING FROM
SOUTH TO NORTH. DESPITE MUCH LOWER PW TODAY...THIS TRAINING WILL
CAUSE MINOR FLOODING IN SOME AREAS WHICH ALREADY SAW A FEW TO
SEVERAL INCHES OF RAINFALL YESTERDAY AND OVERNIGHT. ELSEWHERE...
BREAKS OF SUNSHINE WILL AID IN ADDITIONAL DESTABLIZATION AND QUICK
FORMATION OF SCATTERED SHOWERS. WET BULB ZERO AND FZLVLS BETWEEN
7500 AND 8500 FEET WILL PROMOTE HAIL...BUT GIVEN MARGINAL CAPES AM
EXPECTING SUB-SEVERE HAIL AND LITTLE IF ANY WIND THREAT GIVEN WEAK
BOUNDARY LAYER WINDS. SPC/HPC HAS PLACED THE ERN HALF OF THE CWA
IN SLIGHT RISK FOR HAIL AND SEE TEXT FOR EXCESSIVE RAINFALL.

&&

.SHORT TERM /FRIDAY/...
A DRIER DAY EXPECTED FOR FRIDAY...AS UPPER LOW SHIFTS EAST OF PA.
HOWEVER...COOL AIR ALOFT WILL PROMOTE STEEP LAPSE RATES AND SCT
TO NMRS DIURNALLY DRIVEN SHOWERS AND TSTMS. ALTHOUGH SKIES SHOULD
AVERAGE MOSTLY CLOUDY...OCNL BREAKS OF SUNSHINE SHOULD ALLOW AFTN
TEMPS TO CREEP TOWARD NORMAL. ENSEMBLE MEAN 850 TEMPS SUPPORT HIGHS
IN THE U60S AND L70S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
ANY LINGERING EVENING SHRA/TSRA SHOULD COLLAPSE FRI EVENING...AS BLYR
COOLS AND SFC RIDGE BUILDS TOWARD THE AREA. COOL TEMPS ALOFT
ASSOCIATED WITH DEPARTING UPPER LOW MAY RESULT IN JUST A FEW
SHRA/TSRA SAT AFTN. HOWEVER...COVERAGE SHOULD BE NOTICEABLY LESS
THAN FRIDAY. 850 TEMPS MODERATE TO NR 12C SAT AFTN...LIKELY
SUPPORTING HIGHS NR 80F. A WARM FRONT WILL PUSH INTO CENTRAL PA
SUN AFTN...POSSIBLY TOUCHING OFF A FEW PM TSRA.

BULK OF MED RANGE GUIDANCE SHOWING A WEAKENING TROUGH LIFTING
THROUGH THE GRT LKS EARLY NEXT WEEK. ASSOCIATED COLD FRONT APPEARS
LIKELY TO STALL OUT IN THE VICINITY OF PA DURING TUE/WED...BRINGING
A GOOD CHC OF SHRA/TSRA. MONDAY MAY BE THE WARMEST DAY OF THE
EXTENDED FCST...WHEN GEFS 850 TEMPS PEAK ARND 15C...INDICATING
WIDESPREAD 80S POSSIBLE.

&&

.AVIATION /16Z THURSDAY THROUGH MONDAY/...
STLT IMAGERY SHOWS UPPER LEVEL LOW PRESSURE OVR ERN OH EARLY THIS
MORNING. EXPECT UNSETTLED CONDITIONS TO CONTINUE TDY AS THIS
SYSTEM SLIDES SLOWLY EWD ACRS CNTRL PA. COLD AIR ALOFT AND LIFT
ASSOCIATED WITH THE UPPER LEVEL CIRCULATION WILL PROMOTE INC CVRG
OF SHOWERS AND ISOLD TSTMS THRU THIS AFTN. EARLY MRNG IFR FOG AND
LOW STRATUS WILL IMPROVE TO MVFR/VFR THRU MID-DAY. LOW CIGS AND
PATCHY FOG IS PSBL OVRNGT BUT CONFIDENCE IS MEDIUM TO LOW AS THE
UPPER LOW SHIFTS INTO ERN PA.

OUTLOOK...
FRI...SCT SHOWER POSSIBLE...MAINLY ERN SXNS.
SAT...NO SIG WX EXPECTED.
SUN-MON...MAINLY VFR...BUT SCT TSTMS MAINLY W HALF.

&&

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

&&

SYNOPSIS...STEINBUGL
NEAR TERM...DEVOIR/STEINBUGL
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/RXR
AVIATION...STEINBUGL

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1147 AM EDT THU MAY 19 2011

PAZ004>006-010>012-017>019-026>028-036-037-041-042-045-046-049>053-
056>059-063>066-201600-
WARREN-MCKEAN-POTTER-ELK-CAMERON-NORTHERN CLINTON-CLEARFIELD-
NORTHERN CENTRE-SOUTHERN CENTRE-HUNTINGDON-MIFFLIN-JUNIATA-FRANKLIN-
TIOGA-NORTHERN LYCOMING-SULLIVAN-SOUTHERN CLINTON-SOUTHERN LYCOMING-
UNION-SNYDER-MONTOUR-NORTHUMBERLAND-COLUMBIA-PERRY-DAUPHIN-
SCHUYLKILL-LEBANON-CUMBERLAND-ADAMS-YORK-LANCASTER-
1147 AM EDT THU MAY 19 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

A SLOW MOVING STORM SYSTEM PASSING OF PENNSYLVANIA WILL PRODUCE
SCATTERED THUNDERSTORMS TODAY...MAINLY DURING THE AFTERNOON. A
FEW ISOLATED LOCATIONS COULD EXPERIENCE LARGE HAIL...DAMAGING
WINDS OR FLOODING WITH THE STRONGEST OF THESE STORMS.

.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.

PAZ024-025-033>035-201600-
CAMBRIA-BLAIR-SOMERSET-BEDFORD-FULTON-
1147 AM EDT THU MAY 19 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA.

.DAY ONE...THIS AFTERNOON 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.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
127 PM EDT THU MAY 19 2011

PAZ058-059-066-191800-
LANCASTER PA-LEBANON PA-SCHUYLKILL PA-
127 PM EDT THU MAY 19 2011

...A STRONG THUNDERSTORM WILL AFFECT EASTERN LEBANON...NORTH CENTRAL
LANCASTER AND SOUTH CENTRAL SCHUYLKILL COUNTIES...

AT 122 PM EDT...A STRONG THUNDERSTORM WAS NEAR CORNWALL...MOVING
NORTH AT 30 MPH.

WIND GUSTS TO 30 MPH AND SMALL HAIL ARE POSSIBLE WITH THIS STORM.
VERY HEAVY RAIN WILL FALL FROM THIS STORM...AND WILL CAUSE WATER TO
POND ON ROADS AND FILL POOR DRAINAGE AREAS. THE RAIN WILL CAUSE RAPID
RISES ON SMALL STREAMS AND CREEKS. THIS STORM WILL BE NEAR MYERSTOWN
AROUND 140 PM...PINE GROVE AROUND 150 PM AND TREMONT AROUND 200 PM.

THIS WILL IMPACT THE FOLLOWING CENTRAL PENNSYLVANIA INTERSTATES...THE
PENNSYLVANIA TURNPIKE BETWEEN MILE MARKERS 263 AND 274...I-78 BETWEEN
MILE MARKERS 1 AND 8...I-81 BETWEEN MILE MARKERS 95 AND 111.

THIS WILL ALSO IMPACT THE FOLLOWING MAJOR ROADS...ROUTE 22...ROUTE
209...ROUTE 322...ROUTE 422...STATE ROAD 501.

LAT...LON 4053 7620 4051 7625 4051 7634 4049 7643
      4037 7623 4019 7630 4022 7652 4066 7651
      4067 7617

FORECASTER: EVANEGO