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000
FXUS61 KCTP 110946
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
546 AM EDT TUE MAR 11 2014

.SYNOPSIS...
A VIGOROUSLY DEEPENING LATE WINTER STORM SYSTEM WILL IMPACT THE
AREA ON WEDNESDAY...FOLLOWED BY COLD AND BLUSTERY CONDITIONS FOR
END OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
GUSTY WINDS ARE OCCURRING THIS MORNING AFTER A TROUGH OF LOW
PRESSURE PASSED THROUGH THE REGION. GUSTS INTO THE 30S HAVE BEEN
REPORTED ON THE HIGHER TERRAIN OF THE WEST AND CENTRAL MTS. THE
VALLEYS OF THE EAST HAVE NOT MIXED...AND TEMPS THERE ARE STUCK IN
THE LOWER 30S. FOR CONTRAST...JST IS 47F AT 4 AM. THE WEST FLOW
WILL SLACKEN A BIT FOR THE DAYTIME...BUT DEEPER MIXING IN THE
DAYLIGHT WILL ONLY ALLOW IT TO DIMINISH TO AROUND 5 TO 10 KTS.
MOISTURE TAKING THE LONG ROUTE FROM THE PACIFIC IS RIDING A
BOUNDARY OF GENERALLY WEAK NATURE WITH SIMILAR AIR MASSES TO THE
N AND SOUTH OF IT. ONLY HIGH CLOUDS ARE EXPECTED TODAY. A SPRINKLE
MAY BE POSSIBLE LATE IN THE DAY AS THE MSTR WORKS DOWN FROM
ALOFT...BUT HAVE ONLY MENTIONED IT OVER THE NW AT THIS POINT. THE
TEMPS WILL AGAIN BE ABOVE NORMAL THIS AFTERNOON WITH HIGHS IN THE
50S ALMOST EVERYWHERE EXCEPT U40S N AND L60S S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
MOISTURE ALOFT CONTINUES TO THICKEN UP TONIGHT. SUB-TROPICAL HIGH
CENTERED EAST OF THE BAHAMAS WILL SUPPLY THE GOOD SRLY FLOW AND
REAL GOMEX MOISTURE TO A STRONG SYSTEM DROPPING SE FROM THE HIGH
PLAINS INTO MO LATER TODAY. THE SUB-1000MB LOW WILL DEEPEN EVEN
FURTHER AS IT ROLLS EASTWARD ALONG THE WEAK BOUNDARY OVER THE OH
VALLEY AND NRN MID-ATLANTIC STATES. THE LOW IS PROGGED BY ALL MDLS
TO CROSS THE SRN TIER OF PA WED - AT 12Z IT SHOULD BE ENTERING FAR
SWRN PA...AND WILL DEEPEN TO A 980MB LOW BY THE TIME IT SCOOTS
EAST OF KABE WED EVENING. VERY STRONG AND NEAR-TEXTBOOK KISSING JET
COUPLET WILL ENHANCE THE LIFT AND FRONTOGENESIS AS IT MOVES
THROUGH THE STATE. THE WARM AIR TO THE SOUTH AND THE ALREADY-
ANOMALOUSLY WARM TEMPS WILL KEEP THE PRECIP RAIN OVER ALL BUT THE
FAR NRN TIER BEFORE LATE WED. EVEN THE FAR NRN TIER WILL PROBABLY
HAVE TROUBLE ACCUMULATING WHAT DOES FALL AS SNOW...DUE TO THE MID-
MARCH SUN AND MARGINAL TEMP PROFILE. LIGHT EAST WIND COULD KEEP
TEMPS NEAR FREEZING IN THE NRN MTS WED MORNING. SOME POCKETS OF
FZG RAIN MAY THEREFORE EXIST IN THE NRN TIER WED. AS THE LOW
DEEPENS AND PASSES TO THE EAST...THE WINDS WILL GO NORTHERLY AND
INCREASE QUITE RAPIDLY. SUSTAINED SPEEDS IN THE 20S AND GUSTS NEAR
40 MPH ARE EXPECTED AS STRONG CAA DROPS TEMPS INTO THE 20S IN THE
N WED AFTN.

QPF IN THE 1-1.25 INCH RANGE ACROSS THE NORTH IS MOST LIKELY GOING
TO BE MOSTLY RAIN...BUT THE STRONG COLD ADVECTION AND COUPLED JET
LATER IN THE DAY WILL MAKE MESOSCALE SNOW BAND/S AND TEMPS WILL
THEN BE CONDUCIVE TO ALLOW ACCUMULATION. THUS...THE ACCUMULATIONS
COULD REACH 6 INCHES OR MORE ALONG THE NRN TIER BY LATE WED NIGHT.
THE COLD WINDS WILL HELP MINS INTO THE LOWEST SINGLE DIGITS IN THE
N. THIS WILL ALSO LEAD TO LOW WIND CHILLS. HAVE THUSLY ISSUED A
WINTER STORM WATCH FOR THE 4 NRN TIER COS ALONG THE NY BORDER.

ACCUMULATIONS WILL BE MAINLY SLUSH - AND AT MOST AN INCH OR TWO
ANYWHERE SOUTH/EAST OF ALTOONA/STATE COLLEGE/WILLIAMSPORT.
RAINFALL IN THE SOUTH/EAST WILL BE PRETTY LIGHT. SEE HYDRO SECTION
FOR MORE.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AFTER THE STORM...QUITE COLD AIR...AROUND -20C AT 850MB...GETS
DRIVEN INTO THE REGION ON A STRONG GUSTY NW WIND LATER WED NIGHT
INTO THU...WITH BY FAR THE COLDEST DAY OF THE WEEK IN STORE
THURSDAY. WIND CHILLS SHOULD REACH NEAR ADVISORY CRITERIA OVER THE
NRN MTNS AND LAUREL HIGHLANDS...RANGE FROM 0 TO -10F OVER THE
CENTRAL RIDGE/VALLEY REGION AND DIP TO AROUND ZERO IN THE LWR
SUSQ. VLY.

THE WELL-BELOW NORMAL COLD WILL BE SHORT-LIVED THOUGH...AS TEMPS
REBOUND DECENTLY FRI INTO SAT...BOUNCING BACK TO NEAR SEASONAL
NORMALS. HOWEVER THIS WINTER`S DEFINING FEATURE...THE PERSISTENT
WEST COAST RIDGE...IS AGAIN EXPECTED TO RE-ESTABLISH ITSELF
HEADING INTO NEXT WEEK. THIS WILL ALLOW FOR COOLER AIR TO FILTER
BACK INTO THE REGION IN PERSISTENT NW FLOW OVER PA...KEEPING TEMPS
NEAR OR SLIGHTLY BELOW NORMAL AND PREVENTING ANY KIND OF
SIGNIFICANT WARM UP.

&&

.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
09Z TAFS SENT.

MOST LOCATIONS WINDS HAVE DIED DOWN. NEVER GOT THE WIND TO
THE EAST...THUS LEFT LLWS IN.

WINDS AT AOO WERE QUITE STRONG...BUT ARE MUCH WEAKER NOW.

JST STILL HAVING WINDS TO 35 KNOTS.

ADJUSTEMENTS MADE TO 09Z TAFS.

EARLIER DISCUSSION BELOW.

MAINLY CLEAR OUT...WITH VERY STRONG WIND FIELDS. ADDED LLWS TO
A FEW SITES. OFF DUTY STAFF IN AOO HAVE WIND GUST TO AROUND
40 MPH.

MORE ADVERSE CONDITIONS ON WED...CONCERN WILL BE STRONG WIND
FIELDS...LLWS...RAIN ACROSS MUCH OF THE AREA...PERHAPS SOME
SNOW ACROSS THE NW...AND SOME RISK OF STRONG TO EVEN SEVERE
THUNDERSTORMS NEAR THE MD BORDER. THIS WILL BE FOLLOWED BY
MORE STRONG WINDS LATE WED INTO EARLY THU...AS VERY COLD AND
DRY AIR ADVECTED SOUTHWARD INTO THE AREA.

SATELLITE LOOP SHOWS MAINLY CLEAR SKIES ACROSS CENTRAL PA AS OF
03Z. THE MAIN AVIATION CONCERN LATE THIS EVENING WILL BE THE
THREAT OF LLWS. A CORE OF STRONG WINDS ALOFT WILL PUSH OVER
CENTRAL PA THIS EVENING IN ASSOCIATION WITH APPROACH OF DYING COLD
FRONT. MDL SOUNDINGS INDICATE LLWS CRITERIA WILL LIKELY BE MET
OVER MUCH OF CENTRAL PA BTWN 03Z-07Z WITH LESS OF A CHANCE ACROSS
THE AIRFIELDS OF SOUTHEAST PA.

CORE OF STRONG WINDS ALOFT SHOULD WEAKEN AS DYING FRONT STALLS
OUT ACROSS SOUTHERN PA...RESULTING IN A DIMINISHING THREAT OF LLWS
AFTER ABOUT 07Z. THERE IS SOME CONCERN THAT PLUME OF LOW LVL MOISTURE
ALONG FRONT...COMBINED WITH OROGRAPHIC LIFT...COULD PRODUCE A
PERIOD OF MVFR CIGS AT KJST LATE TONIGHT AND TUE AM.

ANY LOWER CIGS ARND KJST SHOULD LIFT TO VFR BY MIDDAY. FOR TUE
AFTN...GENERALLY VFR CONDS APPEAR LIKELY...WITH THE HIGHEST
CONFIDENCE OF VFR CONDS ACROSS THE EASTERN HALF OF THE STATE...DUE
TO DRYING...DOWNSLOPING WEST WIND.

OUTLOOK...
WED...MVFR-IFR RESTRICTIONS LKLY IN RAIN AND/OR SNOW. WINDY LATE.
THU...STRONG/GUSTY NNW WINDS POSSIBLE.
FRI-SAT...NO SIG WX EXPECTED.

&&

.HYDROLOGY...
WITH WARMER TEMPERATURES AND MIDWEEK RAINFALL...EXPECT MODERATE
RISES ON RIVERS AND STREAMS MAINLY FOR THE SOUTHERN HALF OF THE
CWA. STILL ENOUGH ICE IN SPOTS TO BRING ICE JAMS...THOUGH
SIGNIFICANT DECAY HAS OCCURRED AT MANY LOCATIONS. ANY ICE JAMS
WILL BE ISOLATED IN NATURE. ALL PERSONS SHOULD MONITOR WATER
LEVELS CLOSELY FOR THE REST OF THE WEEK.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH LATE
WEDNESDAY NIGHT FOR PAZ004>006-037.

&&

$$
SYNOPSIS...DANGELO/RXR
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/MARTIN
HYDROLOGY...CR