Special Weather Statement, NWS State College, PA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1101 AM EDT THU JUL 19 2012

.SYNOPSIS...
A STATIONARY FRONT WILL REMAIN DRAPED ACROSS CENTRAL PENNSYLVANIA
TODAY. A SLOW MOVING WAVE OF LOW PRESSURE WILL RIDE ALONG THIS
BOUNDARY...PASSING JUST SOUTH OF PENNSYLVANIA FRIDAY AND SATURDAY.
A WEAK RIDGE OF HIGH PRESSURE WILL BUILD SOUTH ACROSS THE AREA
SUNDAY AND MONDAY.

&&

.NEAR TERM /UNTIL 7 PM THIS EVENING/...
TAIL OF HIGH REL VORT IS DRAPED FROM NY/CT INTO THE CENTRAL MTS.
THE FORCING IS CREATING A LINE OF SHOWERS OVER THE EASTERN MTS AND
MID-SUSQ VALLEY. THESE SHOWERS ARE MOVING QUICKLY TO THE ESE.
WILL CONTINUE TO HOLD HIGHEST POPS OFF UNTIL LATE AFTN WHEN
PARTIAL CLEARING AND A MAJOR WAVE ARRIVES FROM THE NW. THE MCS
FROM LAST NIGHT STILL HAS A BOW LOOK TO IT BUT WITH ONLY MODEST
GUSTS ASSOCIATED WITH IT. HOWEVER...DIURNAL HEATING OF
MOIST/UNSTABLE AIR MASS AHEAD OF THIS FEATURE SHOULD RESULT
NUMEROUS/WIDESPREAD TSRA. SVR THREAT NOT PARTICULARLY
HIGH...GIVEN WEAK SHEAR. HOWEVER...MODERATE CAPES INDICATED BY
LATEST MDL GUIDANCE SUGGEST A FEW STRONG PULSE-TYPE STORMS ARE
LIKELY - ESP IN THE SWRN HALF TO TWO-THIRDS OF THE AREA. THE
COOLER AND DRIER AIR TO THE NORTH OF THE FRONT WILL MOST LIKELY
KEEP CONVECTION SUPPRESSED OR AT LEAST WEAKER IN THE NERN MTS.
CLOUDS ARE KEEPING THE HEATING DOWN FOR A BIT...BUT THE CAP SHOULD
BE TAKEN AWAY AS THE SUN AND WRLY FLOW ALOFT MIX IT UP AND PUSH
MAXES INTO THE 80S...AND PERHAPS CLOSE TO THE 90F MARK IN THE FAR
SE.

&&

.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM FRIDAY/...
MDLS HAVE TRENDED DEEPER AND FURTHER NORTH WITH SHORTWAVE TROF
DROPPING INTO THE OHIO VALLEY FRIDAY...RESULTING IN INCREASING
CONFIDENCE OF A SUBSTANTIAL RAINFALL ACROSS CENTRAL PA BTWN
TONIGHT AND FRI NITE...AS SLOW MOVING WAVE OF LOW PRESSURE PASSES
SOUTH OF THE MASON DIXON LINE. 00Z GEFS INDICATING ANOMALOUS
EASTERLY LL JET AND PWATS FOCUSED ALONG THE N TIER COUNTIES
TONIGHT...THEN SHIFTING SOUTHWARD ACROSS PA FRI AND FRI NITE. THIS
SIGNATURE IN THE ENSEMBLE DATA POINTS STRONGLY TOWARD SIGNIFICANT
PRECIP EVENT. CURRENT GEFS MEAN QPF RANGES BTWN 1-2 INCHES ACROSS
CENTRAL PA...WITH THE HIGHEST TOTALS INDICATED ACROSS EAST CENTRAL
PA. OROGRAPHIC ENHANCEMENT WOULD FAVOR LOCALLY HIGHER AMTS ON THE
EAST /WINDWARD/ SLOPES OF THE APPALACHIANS. A QUICK LOOK AT FFG
AND HEADWATER GUIDANCE INDICATES WIDESPREAD FLOODING VERY UNLIKELY
DUE TO THE DRY ANTECEDENT CONDITIONS. HOWEVER...SOME MDL DATA
INDICATING THE POTENTIAL OF LOCALIZED RAINFALL AMTS OF UP TO 4
INCHES...WHICH COULD CAUSE MINOR FLOODING DESPITE THE DRY CONDS.

HAVE RAISED POPS TO CATEGORICAL OVR MOST OF THE AREA TONIGHT THRU
FRI NITE BASED ON STRONG SUPPORT FROM SREF AND GEFS DATA. CLOUD
COVER...RAINFALL AND UPSLOPING E FLOW SHOULD RESULT IN A COOL
FRIDAY WITH HIGH TEMPS ACROSS THE NORTH CENTRAL MTNS ONLY IN THE
U60S WITH LOW 70S ACROSS SOUTHERN PA.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LINGERING DAMPNESS NOW APPEARS LIKELY ON SATURDAY...AS SLOW MOVING
SFC LOW PASSES SOUTH OF PA. PERSISTENT...MOIST EASTERLY FLOW
SHOULD KEEP LOW CLOUDS AND OCNL LIGHT RAIN/DRIZZLE OVR THE
REGION...ESP SOUTHERN PA. HAVE LOWERED TEMPS CONSIDERABLY /MAINLY
LOW TO MID 70S/...DUE TO THE EXPECTED CLOUD COVER AND LINGERING -RA.

DRIER CONDS SHOULD FINALLY OVERSPREAD THE REGION BY SAT NITE/SUNDAY...
AS SFC LOW PASSES OFF THE MID ATL COAST. HOWEVER...ARRIVAL OF A
WEAK SHORTWAVE CROSSING THE GRT LKS COULD PRODUCE ENOUGH LIFT FOR
A FEW PM TSRA ON SUNDAY.

A DRY NW FLOW PATTERN APPEARS LIKELY EARLY NEXT WEEK WITH TEMPS A
BIT ABV SEASONAL NORMS BASED ON ENS MEAN 850 TEMPS. A COUPLE OF
SHORTWAVES DIVING SE ACROSS THE REGION COULD BRING A SHRA/TSRA TO
PARTS OF THE AREA MON/TUE. HOWEVER...GEFS PWATS NOT IMPRESSIVE...SO
SIG RAINFALL SEEMS UNLIKELY.

&&

.AVIATION /15Z THURSDAY THROUGH MONDAY/...
SFC FRONTAL BOUNDARY VERY DIFFICULT TO PLACE IN SFC ANALYSIS AT
THIS TIME...BUT BEST CONVERGENCE AND SWITCH OF WIND DIR IS S OF
KBFD AND N OF KFIG AND CLOSE TO KIPT. IT SHOULD MOVE VERY LITTLE.
MCS MOVING IN FROM OH SHOULD BRING TSRA INTO KBFD BY 18Z. A
STRONGER WAVE OF LOW PRESSURE WILL MOVE EAST ALONG THE FRONT LATER
TONIGHT AND CREATE WIDESPREAD SHRA/TSRA. EASTERLY FLOW TO THE
NORTH OF THE FRONT AND GENERALLY LIGHT FLOW ELSEWHERE WILL LEAD TO
AREAS OF FOG/LOW CIGS TONIGHT WHICH WILL THEN BE TOUGH TO BREAK ON
THURSDAY. MORE FORCING FROM THE WEST WILL MAKE MORE RAIN ON THURS.
CONVECTIVE POTENTIAL IS LOWER ON THURS DUE TO EXPECTED LACK OF
CLEARING. UNSETTLED CONDITIONS WILL PERSIST INTO SAT AS
ADDITIONAL WAVES OF LOW PRESSURE MOVE ALONG THE FRONT.

OUTLOOK...
FRI-SAT...MVFR BECOMING IFR WITH PERIODS OF RAIN AND SCT TSTMS
CENTRAL/SOUTH.
SUN...MVFR/IFR IN THE MORNING...THEN IMPROVING CONDITIONS.
MON...MAINLY VFR...SCT PM TSTMS POSSIBLE.

&&

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

&&

SYNOPSIS...FITZGERALD
NEAR TERM...DANGELO
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...DANGELO/MARTIN

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1220 PM EDT THU JUL 19 2012

PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-049>053-
056>059-063>066-201630-
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-
1220 PM EDT THU JUL 19 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

A WIDESPREAD HEAVY RAINFALL OF 1 TO 3 INCHES IS LIKELY FRIDAY
AND FRIDAY NIGHT...AS A WAVE OF LOW PRESSURE MOVING EAST ALONG A
STALLED OUT FRONT CREATES A DEEP SOUTHEASTERLY FLOW OF MOISTURE
OFF THE ATLANTIC.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

LAMBERT

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
313 PM EDT THU JUL 19 2012

PAZ017-024-192030-
CAMBRIA PA-CLEARFIELD PA-
313 PM EDT THU JUL 19 2012

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT NORTHERN CAMBRIA AND
SOUTHWESTERN CLEARFIELD COUNTIES THROUGH 430 PM EDT...

AT 310 PM EDT...A LINE OF STRONG THUNDERSTORMS WAS LOCATED FROM
REYNOLDSVILLE TO BIG RUN TO GLEN CAMPBELL TO CHEVY CHASE HEIGHT...
MOVING EAST AT 20 MPH.

WESTERLY WIND GUSTS TO 35 MPH ARE POSSIBLE WITH THESE STORMS. THESE
STORMS WILL AFFECT DUBOIS...TROUTVILLE...MAHAFFEY...AND
BURNSIDE...ROCKTON...AND NEW WASHINGTON...BELSANO...NORTHERN
CAMBRIA...WESTOVER AND LUMBER CITY.

THIS WILL IMPACT I-80 BETWEEN MILE MARKERS 102 AND 125.

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

LAT...LON 4072 7881 4114 7881 4109 7832 4089 7826
      4081 7831 4079 7834 4077 7835 4076 7838
      4074 7837 4052 7858 4054 7890

FORECASTER: LAMBERT