Flash Flood Warning 77, NWS State College, PA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
332 PM EDT WED SEP 28 2011

.SYNOPSIS...
THE MIDWEST UPPER LOW CENTER NEAR THE SOUTHERN END OF LAKE
MICHIGAN WILL MOVE INTO NORTHERN INDIANA BY THIS EVENING. THIS
PERSISTENT FEATURE WILL FINALLY OPEN AND ACCELERATE EASTWARD
THROUGH THE NORTHERN MID ATLANTIC STATES INTO NEW ENGLAND BY
THURSDAY NIGHT. ANOTHER UPPER LEVEL DISTURBANCE WILL DIG
SOUTHEASTWARD ACROSS THE GREAT LAKES AND CARVE OUT A DEEP TROUGH
OVER THE EASTERN U.S. BY THE WEEKEND. NORTHWESTERLY FLOW
ACCOMPANYING THE TROUGH WILL DIRECT MUCH COLDER AIR INTO THE
REGION WITH TEMPERATURES FALLING WELL BELOW NORMAL FROM FRIDAY
THROUGH SUNDAY.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
IT LOOKS LIKE THE POTENTIAL FOR EXCESSIVE RNFL AND FLASH FLOODING
WILL CONTINUE INTO TONIGHT AS BANDING OF SHOWERS WITH HEAVIER
PRECIP CONTINUES. FF WATCH HAS BEEN EXTENDED THROUGH MIDDAY
THURSDAY.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
UPPER LOW WOBBLES AROUND OVER THE OHIO VALLEY THRU THE PERIOD. THE
OCCLUSION STAYS SOMEWHERE OVERHEAD...AND THE /SOMEWHERE/ IS THE
PROBLEM IN THE FORECAST. MOST MDLS HAVE ALSO WOBBLED BACK AND
FORTH WITH THE PLACEMENT OF THE HEAVIEST CORRIDOR OF PRECIP/SHRA
FOR THE PERIOD. WE/VE SEEN THIS BEFORE /THIS MONTH/ IN LEE AND
EVEN BEFORE DURING IRENE. THERE SEEMS TO BE NO SENSE IN CHOOSING
ANY ONE MODEL BUT GOING FOR THE BIG PICTURE. DEEP S/E FLOW WILL
CONTINUE. ALL AREAS WILL SEE RAIN - AND MANY WILL HAVE HEAVY RAIN
AT THAT. THE TIMING IS ALSO SUSPECT BUT THE FORCING MOVING IN FROM
THE SOUTH DURING THE MORNING WILL LEAD TO A TRAIN OF SHOWERS WHICH
WILL LAST MUCH OF THE DAY /ALA TODAY/ BUT THE PLACEMENT WILL BE
SUSPECT. MORE INDICATIONS NOW THAT THE WRN HIGHLANDS COULD SEE THE
HEAVIEST RAIN ON WED. WILL SHIFT THE RAIN FCST FROM THE EAST A BIT
AND PUT HIGHEST POPS OVER THE CENTRAL COS...AND TAPER TO LIKELIES
TO BOTH THE W AND E. WILL HOLD THAT THOUGHT BUT TAKE POPS DOWN
10-20 PCT INTO THE 50-70 PCT RANGE. TEMPS AN AFTERTHOUGHT AND WILL
RUN WITH GMOS AND BLEND WITH CURR.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AFTER LINGERING FOR SEVERAL DAYS...SPRAWLING UPPER LOW BREAKS DOWN
QUICKLY ON THU...AND LIFTS NE OF THE REGION THU NIGHT LEAVING MOST
AREAS DRY. POTENT SYSTEM QUICKLY APPROACHES IN ITS WAKE FROM THE
WEST...PUSHING SHOWERS BACK INTO THE NW MTNS BY LATE THU NIGHT.
TEMPS REMAIN MILD...BOTTOMING OUT NEAR SEASONAL NORMALS.

BIG CHANGES ON THE WAY FOR FRI INTO THE WEEKEND AS COLD FRONT
QUICKLY PUSHES THROUGH ON FRI...FOLLOWED BY AIRMASS-CHANGING
SECONDARY COLD FRONT LATE FRI/FRI NIGHT AS YET ANOTHER POTENT
SHORTWAVE CARVES OUT AN EVEN DEEPER TROUGH. TEMPS FRIDAY WILL LIKELY
PEAK AROUND MIDDAY IN THE WEST AND THEN SLOWLY FALL IN THE
AFTERNOON.

FIRST COLD BLAST OF THE SEASON ARRIVES IN FULL FORCE FRI NIGHT INTO
SAT...AS 545 500MB HEIGHTS AND 850MB TEMPS OF -2C TO -4C MOVE IN.
HIGHS ON SAT LIKELY REMAINING IN THE 40S ACROSS THE NW HALF OF
CWA...AND STRUGGLING TO THE MID 50S IN THE SE...PUTTING TEMPS NEAR
15F BELOW NORMAL.  PRECIPITATION WITH THIS TROUGH SHOULD BE MAINLY
CONFINED TO HIGHER ELEVATIONS OF THE N AND W AS ANOMOLOUSLY COLD AIR
SLIDES ACROSS THE GLAKES...FAVORING PLENTY OF CLOUDS ALONG WITH
SCT/NUMEROUS LAKE EFFECT/UPSLOPE SHOWERS. SE WILL REMAIN DRY IN
DOWNSLOPE FLOW.

TEMPS RECOVER A LITTLE ON SUNDAY...THOUGH ANOTHER COOL DAY IN STORE
AS TEMPS EDGE BACK INTO THE 50S. RIDGE BEGINS TO BUILD IN FROM THE
WEST BY MON/TUE WITH NORTHWEST FLOW...AS TEMPERATURES GRADUALLY
CREEP BACK TOWARD NORMAL UNDER MOSTLY SUNNY SKIES.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
A LARGE UPPER LOW NEAR CHICAGO WILL KEEP DEEP MOIST SOUTHERLY FLOW
LOCKED IN OVER THE REGION THROUGH WEDNESDAY BEFORE FINALLY LIFTING
OUT AND ALLOWING FOR A BRIEF PERIOD OF COOLER AND DRIER AIR TO
MOVE IN LATER IN THE WEEK.

EXPECT VFR AROUND 18Z WITH ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS MID TO LATE AFTERNOON. WITH HEAVY RAINSHOWERS AGAIN
THIS AFTERNOON THERE WILL BE ONE MORE ROUND OF PATCHY
FOG...STRATUS TONIGHT...ESPECIALLY WITH CLEARING SKIES OVERNIGHT.
EXPECT MVFR/IFR IN THUNDERSTORMS THIS AFTERNOON WITH LOCALLY HEAVY
RAINFALL.

A PATTERN SHIFT WILL OCCUR LATE THIS WEEK AS THE UPPER LOW THAT
HAS DOMINATED WILL EXIT THE REGION USHERING NORTHWESTERLY
FLOW...COOLER TEMPS AND UPSLOPE FLOW IN THE NW MTNS.

OUTLOOK...

THU...AM FOG POSSIBLE
FRI-SAT...LOW CIGS/SHRA POSS W MTNS...MAINLY
AT NIGHT. SUN...IMPROVING TO VFR. MVFR POSS IN NW MTNS.

&&

.HYDROLOGY...
AT THIS TIME...SWATARA CREEK THE ONLY PLACE WHERE RIVER FLOODING IS
FORECAST...AND IT SHOULD CREST TONIGHT AND THURSDAY. THOUGH SEVERAL
POINTS IN THE EASTERN PORTIONS OF CWA CONTINUE TO RUN HIGH...AND ARE
FOR FORECAST TO CREST NEAR FLOOD STAGE OVER THE NEXT DAY OR SO.

OVERALL PATTERN WILL NOT CHANGE MUCH THROUGH TONIGHT AS A DEEP UPPER
LOW CONTINUES TO PUMP ANOMALOUSLY MOIST AIR INTO THE REGION. FLASH
FLOOD WATCH IN EFFECT THROUGH MIDDAY THU FOR THE EASTERN HALF OF PA.
A COUPLE OF BANDS OF HEAVIER SHOWERS AFFECTING ISOLATED AREAS OF
CENTRAL PA THIS AFTERNOON...BUT THIS AREA OF RAIN EXPECTED TO EXPAND
OVERNIGHT AND ANY TRAINING OF STORMS COULD CREATE ADDITIONAL
PROBLEMS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR PAZ006-011-
012-018-019-026>028-035>037-041-042-045-046-049>053-056>059-
063>066.

&&

SYNOPSIS...STEINBUGL/RXR
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...RXR
AVIATION...LA CORTE/CERU
HYDROLOGY...RXR

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
258 PM EDT WED SEP 28 2011

PAZ004-005-010-017-024-025-033-034-291900-
WARREN-MCKEAN-ELK-CLEARFIELD-CAMBRIA-BLAIR-SOMERSET-BEDFORD-
258 PM EDT WED SEP 28 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

SCATTERED SHOWERS AND THUNDERSTORMS WILL AFFECT THE REGION
THROUGH TONIGHT. SOME MAY CONTAIN LOCALLY HEAVY RAIN...BUT NO
WIDESPREAD HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

PAZ006-011-012-018-019-026>028-035>037-041-042-045-046-049>053-
056>059-063>066-291900-
POTTER-CAMERON-NORTHERN CLINTON-NORTHERN CENTRE-SOUTHERN CENTRE-
HUNTINGDON-MIFFLIN-JUNIATA-FULTON-FRANKLIN-TIOGA-NORTHERN LYCOMING-
SULLIVAN-SOUTHERN CLINTON-SOUTHERN LYCOMING-UNION-SNYDER-MONTOUR-
NORTHUMBERLAND-COLUMBIA-PERRY-DAUPHIN-SCHUYLKILL-LEBANON-CUMBERLAND-
ADAMS-YORK-LANCASTER-
258 PM EDT WED SEP 28 2011

...FLASH FLOOD WATCH IN EFFECT THROUGH THURSDAY AFTERNOON...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO
WEATHER.GOV/STATECOLLEGE ON THE INTERNET FOR MORE
INFORMATION ABOUT THE FOLLOWING HAZARDS.

   FLASH FLOOD WATCH.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO
WEATHER.GOV/STATECOLLEGE ON THE INTERNET FOR MORE
INFORMATION ABOUT THE FOLLOWING HAZARDS.

   FLASH FLOOD WATCH.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO REPORT HEAVY RAIN...FLOODING OR ANY
OTHER SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE IN STATE
COLLEGE.

GARTNER

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
136 PM EDT WED SEP 28 2011

PAZ056-057-063>065-281830-
ADAMS PA-CUMBERLAND PA-DAUPHIN PA-PERRY PA-YORK PA-
136 PM EDT WED SEP 28 2011

...A STRONG THUNDERSTORM WILL AFFECT DAUPHIN...NORTHEASTERN ADAMS...
NORTHEASTERN CUMBERLAND...NORTHEASTERN PERRY AND NORTHWESTERN YORK
COUNTIES...

AT 134 PM EDT...A STRONG THUNDERSTORM WAS NEAR WELLSVILLE...MOVING
NORTH AT 25 MPH.

WIND GUSTS TO 40 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 AFFECT
SIDDONSBURG...CAMP HILL...ROCKVILLE...ELLENDALE FORGE AND HALIFAX.

THIS WILL IMPACT THE FOLLOWING CENTRAL PENNSYLVANIA INTERSTATES...THE
PENNSYLVANIA TURNPIKE BETWEEN MILE MARKERS 230 AND 250...I-81 BETWEEN
MILE MARKERS 55 AND 79...I-83 BETWEEN MILE MARKERS 29 AND 50...I-283.

LAT...LON 3996 7714 4061 7701 4055 7662 4049 7664
      4048 7668 4043 7666 3986 7684

FORECASTER: MARTIN

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
227 PM EDT WED SEP 28 2011

PAZ050-052-056-057-281930-
DAUPHIN PA-NORTHUMBERLAND PA-PERRY PA-SNYDER PA-
227 PM EDT WED SEP 28 2011

...A STRONG THUNDERSTORM WILL AFFECT DAUPHIN...NORTHEASTERN PERRY...
SOUTHEASTERN SNYDER AND SOUTHWESTERN NORTHUMBERLAND COUNTIES...

AT 225 PM EDT...A STRONG THUNDERSTORM WAS NEAR LINGLESTOWN...MOVING
NORTH AT 20 MPH.

WIND GUSTS TO 40 MPH ARE POSSIBLE WITH THIS STORM. THIS STORM WILL
AFFECT ELLENDALE FORGE...DEHART DAM...MONTGOMERY FERRY...
ELIZABETHVILLE...BERRYSBURG AND PILLOW.

THIS WILL IMPACT THE FOLLOWING CENTRAL PENNSYLVANIA INTERSTATES...
I-81 BETWEEN MILE MARKERS 66 AND 81...I-83 BETWEEN MILE MARKERS 47
AND 50.

THIS WILL ALSO IMPACT THE FOLLOWING MAJOR ROADS...ROUTE 11/15...ROUTE
22...ROUTE 209...ROUTE 322/22...ROUTE 422.

LAT...LON 4026 7691 4029 7693 4032 7691 4032 7694
      4061 7703 4064 7694 4064 7700 4065 7701
      4068 7706 4073 7707 4077 7672 4048 7666
      4046 7668 4029 7663 4025 7689

FORECASTER: MARTIN

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
310 PM EDT WED SEP 28 2011

PAZ057>059-066-282000-
DAUPHIN PA-LANCASTER PA-LEBANON PA-SCHUYLKILL PA-
310 PM EDT WED SEP 28 2011

...A STRONG THUNDERSTORM WILL AFFECT EASTERN DAUPHIN...NORTHWESTERN
LANCASTER...SOUTHWESTERN SCHUYLKILL AND WESTERN LEBANON COUNTIES...

AT 305 PM EDT...A STRONG THUNDERSTORM WAS NEAR ELIZABETHTOWN...MOVING
NORTH AT 25 MPH.

WIND GUSTS TO 40 MPH AND SMALL HAIL ARE POSSIBLE WITH THIS STORM.
THIS STORM WILL AFFECT HERSHEY...PALMYRA...PENN NATIONAL RACEWAY...
FORT INDIANTOWN GAP AND WILLIAMSTOWN.

THIS WILL IMPACT THE FOLLOWING CENTRAL PENNSYLVANIA INTERSTATES...THE
PENNSYLVANIA TURNPIKE BETWEEN MILE MARKERS 250 AND 264...I-78 BETWEEN
MILE MARKERS 0 AND 6...I-81 BETWEEN MILE MARKERS 75 AND 105.

THIS WILL ALSO IMPACT THE FOLLOWING MAJOR ROADS...STATE HIGHWAY
283...ROUTE 22...ROUTE 209...ROUTE 322...ROUTE 422.

LAT...LON 4062 7680 4061 7638 4049 7641 4049 7643
      4048 7641 4012 7650 4012 7673

FORECASTER: MARTIN

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
355 PM EDT WED SEP 28 2011

PAZ041-042-046-049-051-052-282100-
MONTOUR PA-NORTHERN LYCOMING PA-NORTHUMBERLAND PA-
SOUTHERN LYCOMING PA-SULLIVAN PA-UNION PA-
355 PM EDT WED SEP 28 2011

...A STRONG THUNDERSTORM WILL AFFECT EASTERN LYCOMING...NORTHEASTERN
UNION...NORTHWESTERN NORTHUMBERLAND...NORTHWESTERN SULLIVAN AND
WESTERN MONTOUR COUNTIES...

AT 352 PM EDT...A STRONG THUNDERSTORM WAS NEAR NEW COLUMBIA...MOVING
NORTH AT 30 MPH.

WIND GUSTS TO 40 MPH AND SMALL HAIL ARE POSSIBLE WITH THIS STORM.
THIS STORM WILL AFFECT ALLENWOOD...DELAWARE RUN...MONTGOMERY...
MONTOURSVILLE...LOYALSOCKVILLE AND BARBOURS.

THIS WILL IMPACT THE FOLLOWING CENTRAL PENNSYLVANIA INTERSTATES...
I-80 BETWEEN MILE MARKERS 202 AND 222...I-180 BETWEEN MILE MARKERS
1 AND 28.

THIS WILL ALSO IMPACT THE FOLLOWING MAJOR ROADS...STATE HIGHWAY
147...ROUTE 15...ROUTE 220...STATE ROAD 14...STATE ROAD 45...STATE
ROAD 118.

LAT...LON 4155 7668 4094 7668 4094 7702 4155 7704
      4155 7697 4156 7695

FORECASTER: MARTIN

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
406 PM EDT WED SEP 28 2011

PAZ052-053-058-282100-
COLUMBIA PA-NORTHUMBERLAND PA-SCHUYLKILL PA-
406 PM EDT WED SEP 28 2011

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

AT 404 PM EDT...A STRONG THUNDERSTORM WAS NEAR JOE ZERBEY AIRPORT...
MOVING NORTH AT 30 MPH.

WIND GUSTS TO 40 MPH AND SMALL HAIL ARE POSSIBLE WITH THIS STORM.
THIS STORM WILL AFFECT CENTRALIA...NUMIDIA...MAINVILLE...MIFFLINVILLE
AND ORANGEVILLE.

THIS WILL IMPACT THE FOLLOWING CENTRAL PENNSYLVANIA INTERSTATES...
I-80 BETWEEN MILE MARKERS 233 AND 247...I-81 BETWEEN MILE MARKERS 106
AND 123.

THIS WILL ALSO IMPACT THE FOLLOWING MAJOR ROADS...ROUTE 11...ROUTE
209...STATE ROAD 61.

LAT...LON 4059 7627 4061 7651 4126 7648 4124 7631
      4121 7632 4114 7628 4114 7623 4114 7622
      4103 7622 4096 7621 4095 7619

FORECASTER: MARTIN