Special Weather Statement, NWS State College, PA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
229 PM EDT FRI MAY 4 2012

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL AFFECT CENTRAL PENNSYLVANIA
THROUGH EARLY TONIGHT. HIGH PRESSURE BUILDING SOUTHEAST FROM
CANADA WILL BRING DRIER AND COOLER WEATHER FOR MUCH OF THE
UPCOMING WEEKEND. A COLD FRONT WILL APPROACH FROM THE OHIO VALLEY
MONDAY AND SLOW DOWN AS IT MOVES INTO PENNSYLVANIA MONDAY NIGHT
AND TUESDAY...AS A RESULT OF A DEEPENING UPPER LEVEL TROUGH MOVING
IN FOR THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
ISOLATED TO SCATTERED COVERAGE OF SHOWERS AND THUNDERSTORMS
ONGOING IN 850 MB THERMAL MOISTURE AXIS EXTENDING FROM NORTHEAST
OHIO TO THE LOWER SUSQ NORTH OF THE TRACK OF AN EARLIER MCV
TRACKING SOUTH OF THE MASON DIXON LINE. THESE UPDRAFTS REMAIN ON
THE WEAKER SIDE AND ARE SO FAR PRODUCING BRIEF DOWNPOURS AND ARE
MOVING NICELY EASTWARD WITHOUT SIGN OF TRAINING. ANTICIPATE AT
LEAST A FEW HEAVY RAINERS AND PULSERS TO DEMAND OUR ATTENTION
BEFORE THE AFTERNOON IS OUT...MOST LIKELY IN THE NORTHWEST TO
SOUTHEAST ARC FROM THE NORTHWEST MOUNTAINS TO THE LOWER SUSQ AS
ADVERTISED BY HRRR/COSPA. DESPITE AREA REMAINING IN SPC SLIGHT
RISK THROUGH THIS EVENING...DO NOT EXPECT SEVERE TO BE WIDESPREAD.
ISOLATED CELLS MAY BRIEFLY PULSE SEVERE TO PRODUCE STRONG WIND
GUSTS AND SMALL HAIL.

LEE SFC TROUGH IS ALSO EXPECTED TO BECOME A FOCUS FOR TSTM
DEVELOPMENT IN CONJUNCTION WITH DIURNAL HEATING AND WEAKENING MCV
CIRCULATION BY THIS EVENING. THEREFORE KEPT HIGHEST POPS /50-60 PERCENT/
OVR THE NRN TIER AND LWR SUSQ VLY THROUGH EARLY TONIGHT.

A RIDGE OF HIGH PRESSURE BUILDING OVER SERN CANADA WILL NUDGE THE
MAIN FRONTAL BOUNDARY SWD THRU CENTRAL PA LATER TONIGHT...WITH THE
THREAT OF PCPN GRADUALLY COMING TO AN END FROM NORTH TO SOUTH.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
A MAINLY DRY...COOLER WX PATTERN MOVES IN FOR THE UPCOMING WEEKEND
AS LG SFC ANTICYCLONE BUILDS SE FROM ONTARIO CANADA. LLVL FLOW WILL
BE NORTH TO NERLY...WITH THE FLOW ALOFT NWRLY. THE LONE EXCEPTION
WILL BE ACROSS FAR SRN PENN...WHERE A FLAT SHORT WAVE RIDING OVER
THE EXITING SFC COLD FRONT COULD SPARK A FEW ISOLATED SHOWERS OR A
BRIEF TSRA ON SATURDAY.

TEMPS SATURDAY SHOULD STILL BE ABOUT 5F ABOVE NORMAL...RANGING FROM
THE MID AND UPPER 60S ACROSS THE NRN MTNS...TO THE MID 70S IN THE
SOUTHERN VALLEYS. SIMILAR TEMPS ARE EXPECTED FOR THE CENTRAL AND
NORTH ON SUNDAY...WHILE MAX TEMPS SLIDE ABOUT 5F /COMPARED TO
SATURDAY'S/ OVER THE SOUTH.

AS A RESULT OF THE NOTICEABLY DRIER AIR PUSHING SOUTH INTO THE
STATE...SUNDAY AND MONDAY MORNING WILL BE ON THE CHILLY SIDE /WITH
LOWS IN THE UPPER 30S TO LOWER 40S ACROSS THE NRN MTNS...AND IN THE
UPPER 40S TO LOWER 50S IN THE SOUTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
CLOUDS WILL THICKEN-UP FROM THE WEST LATER SUNDAY NIGHT INTO MONDAY
ALONG...AND THE NE OF A WARM FRONT THAT WILL BE APPROACHING FROM THE
OHIO VALLEY.

THE TIMING OF THE NEXT...EARLY TO MID WEEK COLD FRONT DEPENDS A LOT
ON JUST HOW AMPLIFIED THE LARGE SCALE TROUGH TO ITS WEST
BECOMES...AS SIGNIFICANT SHORT WAVE ENERGY DIGS SSE FROM SCENT
CANADA. GFS/GEFS AND EC CONCUR ON A RATHER RAINY PERIOD SETTING UP
FROM LATE MONDAY THROUGH TUESDAY AS THE COLD FRONT SLOWS AND
STRETCHES OUT ON A NE/SW AXIS. EC 24 HOUR PRECIP TOTALS ARE WELL
OVER AN INCH DURING THIS PERIOD...AND GEFS PLUMES SUPPORT AND EVEN
THE EC GUIDANCE WITH MEAN QPF IN THE DAYS 4.5-6 PERIOD OF APPROX
1.50 INCHES.

MODELS THEN DIVERGE FOR THE SECOND HALF OF THE WEEK WITH RESPECT TO
THE LOCATION OF THE CLOSED UPPER LOW ACROSS THE CENTRAL OR SRN
APPALACHIANS...AND ASSOCIATED SFC CYCLOGENESIS ALONG THE EASTERN
SEABOARD. GEFS IS THE FURTHEST NORTH WITH THE CLOSED LOW OVER LAKE
ERIE...WHILE THE 00Z GFS IS A TAD FURTHER SOUTH...AND THE 00Z EC
PLACES THE CLOSED LOW THURSDAY NEAR ASHEVILLE NC.

UNSETTLED...COOL WX ON TAP FOR LATE NEXT WEEK...AS UPPER TROF SLOWLY
PASSES THRU.

&&

.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
LIFR CONDS OVR THE ERN SITES WILL SLOWLY IMPROVE THRU 15-16Z.
CONFIDENCE REMAINS LOW REGARDING NEAR TERM CONVECTIVE TRENDS OVER
THE NEXT 12HRS. IN GENERAL THERE SHOULD BE SCT TSTMS ACRS MUCH OF
CENTRAL PA BY THE AFTN. DETAILS REGARDING SPECIFIC TERMINAL
IMPACTS WILL NEED TO BE HANDLED AT VERY SHORT RANGES ONCE
INITIATION OCCURS. COLD FRONT WILL PUSH NORTH TO SOUTH TONIGHT
WITH WINDS SHIFTING AROUND TO THE NORTH BY EARLY SAT. THE FRONT
WILL STALL JUST SOUTH OF THE PA/MD LINE TOMORROW.

OUTLOOK...
SAT...ISOLD TSRA IMPACTS PSBL OVER SRN AIRFIELDS.
SUN...VFR.
MON...VFR EARLY...THEN MVFR WITH A CHC OF SHOWERS AND STORMS.
TUE...MVFR WITH SHOWERS AND STORMS.

&&

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

&&

SYNOPSIS...DEVOIR/LAMBERT
NEAR TERM...DEVOIR/STEINBUGL
SHORT TERM...ROSS/DEVOIR/LAMBERT
LONG TERM...LAMBERT/RXR
AVIATION...STEINBUGL

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
102 PM EDT FRI MAY 4 2012

PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-049>053-
056>059-063>066-051715-
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-
102 PM EDT FRI MAY 4 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING. THE MOST LIKELY THREAT IS FOR DAMAGING WIND GUSTS AND
SMALL HAIL...ALONG WITH HEAVY DOWNPOURS AND FREQUENT LIGHTNING
FROM ANY STORMS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

DEVOIR

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
144 PM EDT FRI MAY 4 2012

PAZ056-057-063-041830-
CUMBERLAND PA-DAUPHIN PA-PERRY PA-
144 PM EDT FRI MAY 4 2012

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL DAUPHIN...EAST CENTRAL
PERRY AND NORTHEASTERN CUMBERLAND COUNTIES...

AT 139 PM EDT...A STRONG THUNDERSTORM WAS NEAR SHERMANSDALE...MOVING
EAST AT 30 MPH.

THIS STORM WILL AFFECT MARYSVILLE...ROCKVILLE...LINGLESTOWN AND
SKYLINE VIEW.

THIS STORM MAY PRODUCE SMALL HAIL...GUSTY WINDS TO 40 MPH AND HEAVY
DOWNPOURS.

THIS WILL IMPACT THE FOLLOWING CENTRAL PENNSYLVANIA INTERSTATES...
I-81 BETWEEN MILE MARKERS 59 AND 76...I-83 BETWEEN MILE MARKERS 44
AND 50...I-283.

THIS WILL ALSO IMPACT THE FOLLOWING MAJOR ROADS...ROUTE 11/15...ROUTE
22...ROUTE 322...ROUTE 322/22.

LAT...LON 4045 7673 4023 7672 4029 7718 4037 7720

FORECASTER: DEVOIR

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
320 PM EDT FRI MAY 4 2012

PAZ052-058-041945-
NORTHUMBERLAND PA-SCHUYLKILL PA-
320 PM EDT FRI MAY 4 2012

...A STRONG THUNDERSTORM WILL AFFECT EAST CENTRAL NORTHUMBERLAND AND
WESTERN SCHUYLKILL COUNTIES...

AT 314 PM EDT...A STRONG THUNDERSTORM WAS NEAR ROUGH AND READY...
MOVING EAST AT 25 MPH.

WIND GUSTS TO 50 MPH AND PENNY SIZE HAIL ARE POSSIBLE WITH THIS
STORM. THIS STORM WILL AFFECT MOUNT CARMEL...JOE ZERBEY AIRPORT AND
MINERSVILLE.

LAT...LON 4053 7617 4053 7622 4051 7625 4051 7633
      4061 7663 4062 7664 4079 7662 4081 7639
      4078 7638 4080 7631 4082 7630 4083 7612

FORECASTER: KF