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000
FXUS61 KCTP 172340
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
740 PM EDT THU APR 17 2014

.SYNOPSIS...

A RIDGE OF HIGH PRESSURE FROM THE CANADIAN MARITIMES DOWN THROUGH
THE CAROLINAS WILL KEEP FAIR AND DRY WEATHER ACROSS MOST OF THE
REGION THROUGH FRIDAY. A WEAK COLD FRONT WILL BRUSH NORTHERN AND
WESTERN PENNSYLVANIA LATE TOMORROW AND TOMORROW NIGHT. ANOTHER
AREA OF HIGH PRESSURE WILL BUILD EAST INTO THE COMMONWEALTH FOR
THE WEEKEND. TEMPERATURES WILL MODERATE THIS WEEKEND AND RISE
ABOVE NORMAL BY EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH FRIDAY/...

SATELLITE SHOWS LITTLE IN THE WAY OF CLOUDINESS...WITH EVEN THE
CLOUDS ASSOCIATED WITH THE MARINE LAYER OVER SERN AREAS HAVING
DISSIPATED. THE EVENING WILL REMAIN FAIR...BUT RATHER BREEZY WITH
A SOUTHEASTERLY WIND OF 10-20MPH SLOWLY DIMINISHING OVERNIGHT.

CLOUDS SHOULD REDEVELOP OVER SERN AND EVENTUALLY CENTRAL AREAS AS
WE COLL OVERNIGHT IN THE FACE OF A CONTINUED MOISTENING SELY LOW
LEVEL FLOW. THIS COULD MESS UP THE FROST ADVISORY IF THE CLOUDS
PILE INTO THE LOWER SUSQ BEFORE TEMPS MANAGE TO FALL SUFFICIENTLY.

THE EXPECTED CLOUDS AND HIGHER DEWPOINTS WILL HELP TO CURB THE
TEMP DROP TONIGHT...AND MINS EARLY FRIDAY WILL BE SEVERAL DEGREES
HIGHER THAN EARLIER TODAY.

SOME OF THE TYPICALLY COLDER RURAL VALLEYS COULD SEE DAYBREAK
TEMPS IN THE UPPER 20S...ESPECIALLY IF A PERIOD OF CLEARING
OCCURS. TEMPS ACROSS THE CENTRAL AND NW ZONES WILL BE JUST A TAD
LOWER THAN THOSE LOWER SUSQ COUNTIES COVERED BY THE FROST
ADVISORY.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH 6 PM FRIDAY/...
THE MEAN BLYR FLOW VEERS A BIT MORE TO THE SSE OR SOUTH DURING
THE DAY FRIDAY...WHICH WILL HELP AN ILL-DEFINED WARM FRONT LIFT
NORTH ACROSS THE REGION AND INTO NEW YORK STATE.

A BROAD...NEARLY NORTH-SOUTH AXIS OF LLVL MOISTURE CONVERGENCE
AND HIGHER DEWPOINTS WILL HELP TO CREATE MORE IN THE WAY OF STRATO
CU...THAN THE NEARLY NON-EXISTENT AMOUNTS THAT WE/VE SEEN IN THE
UNUSUALLY COLD...AND BONE-DRY AIRMASS THE PAST FEW DAYS.

OTHERWISE...THE LLVL RIDGE AXIS STAYS IN PLACE ALONG THE MID
ATLANTIC PIEDMONT AND HELPS TO DEFLECT A WEAK NORTHERN STREAM
SYSTEM TO OUR NORTH. A SIGNIFICANTLY STRONGER SRN STREAM STORM
WILL ALSO BE HELD AT BAY WELL TO THE SOUTH OF THE AREA. A FEW
LIGHT SHOWERS MAY GRAZE THE NWRN COS LATE FRIDAY...OR
FRIDAY NIGHT.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
THE 17/12Z MEDIUM RANGE MODEL AND ENSEMBLE GUIDANCE HAS COME INTO
MUCH BETTER AGREEMENT ON THE LARGE SCALE PATTERN EVOLUTION ACROSS
THE LOWER 48 THIS PERIOD...SUPPORTING INCREASING CONFIDENCE IN
THE FORECAST. THE MAIN THEME FOR CENTRAL PA OVER THE NEXT 7+ DAYS
WILL BE A DRY AND RELATIVELY BENIGN WEATHER PATTERN...WITH NO
SIGNIFICANT RAIN-PRODUCING SYSTEMS ON THE HORIZON. THIS SHOULD
CONTRIBUTE TO INCREASING FIRE WEATHER CONCERNS. TEMPERATURES WILL
MODERATE THROUGH NEXT WEEK...TRENDING WARMER WITH THE ODDS FAVORING
A TILT TOWARD THE WARMER-SIDE OF LATE APRIL CLIMATOLOGY.

NRN STREAM SHORTWAVE TROUGH AND SFC COLD FRONT PUSHING EASTWARD
FROM THE GREAT LAKES REGION INTO THE NORTHEAST STATES WILL BRING
SCT...VERY LIGHT RAIN SHOWERS TO NW/N-CENTRAL PA LATE FRIDAY
NIGHT INTO EARLY SATURDAY MORNING. LIMITED RETURN FLOW AND
RELATIVELY COOL/DRY AIRMASS IN PLACE AHEAD OF THIS SYSTEM SHOULD
LIMIT QPF AMTS TO AOB 0.10 INCH. MODEL CONSENSUS KEEPS PCPN
ASSOCIATED WITH CLOSED SRN STREAM LOW TO THE SOUTH OF THE
AREA...WITH CANADIAN HIGH PRESSURE REGAINING CONTROL OF THE
SYNOPTIC PATTERN THROUGH THE REMAINDER OF EASTER WEEKEND.
GUIDANCE TEMPERATURES APPEAR MARGINAL FOR FROST SUN-MON MORNING
ACROSS THE LOWER SUSQ VLY WHERE THE GROWING SEASON IS OFFICIALLY
UNDERWAY.

THE BEST OPPORTUNITY/HIGHEST PROBABILITY FOR APPRECIABLE RAINFALL
/0.25 TO 0.50 INCH AMOUNTS/ OVER THE NEXT 7 DAYS WILL LIKELY COME
ON TUESDAY...WITH SLIGHTLY BETTER MOISTURE IN PLACE AHEAD OF AN
APPROACHING SHORTWAVE TROUGH AND SFC COLD FRONT. THE ECMWF IS MORE
AGGRESSIVE IN BRINGING HEIGHT FALLS INTO THE NORTHEAST ON DAY
7/WED EVENTUALLY CLOSING OFF A 500MB LOW NEAR SOUTHERN NEW ENGLAND.
MEANWHILE THE GFS/GEFS ARE NOT AS STRONG AND GENERALLY MORE
PROGRESSIVE ALOFT...WHICH LEADS TO FASTER HEIGHT RISES HEADING
INTO THE SECOND HALF OF NEXT WEEK. THE SENSIBLE WEATHER HIGHLIGHT
IS PROBABLY A RELATIVE MINIMUM IN DAYTIME HIGH TEMPERATURES FOR
NEXT WEDNESDAY WITH BOTH MODELS/EFS DEPICTING A WEAK NEGATIVE
H5-H7 ANOMALY INVOF THE NEW ENGLAND COAST.

UPPER TROUGH/CLOSED LOW IS PROGGED TO MIGRATE EWD ACROSS THE NRN
ROCKIES INTO THE UPPER MIDWEST WED-FRI. DOWNSTREAM RIDGE AXIS OVER
THE CENTRAL PLAINS/MS VLY/MID-SOUTH SHOULD REACH THE EAST COAST
BY THE END OF NEXT WEEK. THIS SUGGESTS A WARMING TREND FOLLOWING
THE BRIEF COOL-DOWN MIDWEEK WITH MAX TEMPS POSSIBLY HEADING BACK
TO/OR ABOVE 70F.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THIS EVENING. A LAYER OF
SHALLOW/BKN MVFR-LOW END VFR STRATOCU WILL BE SLIDING IN FROM THE
SE OVERNIGHT ACROSS THE LOWER SUSQ VALLEY AIRFIELDS...AND
REACHING THE CENTRAL MTNS EARLY TOMORROW MORNING.

MAINLY SUNNY SKIES WILL CONTINUE WITH SOUTHEAST TO SOUTH-SOUTHEAST
WINDS AVERAGING TO 8-12 KTS WITH OCCASIONAL GUSTS AROUND 20
KTS. THE WIND WILL SUBSIDE BY 00Z.

CHANCE FOR LIGHT RAIN TO IMPACT MAINLY NW LATE FRIDAY AFTERNOON OR
FRIDAY NIGHT WITH LOW PROB OF RESTRICTIONS. VFR ELSEWHERE.

OUTLOOK...
FRI...GENERALLY VFR. AREAS OF MVFR CIGS POSS ACROSS CENTRAL AND SE
PA EARLY.

FRI NIGHT-SAT...REDUCED CIGS/VSBYS POSS WITH CHANCE OF LIGHT RAIN
SHOWERS /MAINLY NW HALF/.

SUN-MON...NO SIG WX.

TUE...A FEW...TO SEVERAL-HOUR PERIOD OF MVFR CIGS WITH BRIEF MVFR
VSBYS IN SHOWERS ACCOMPANYING A COLD FRONTAL PASSAGE.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 2 AM TO 8 AM EDT FRIDAY FOR PAZ057-059-
063>066.

&&

$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...STEINBUGL
AVIATION...LAMBERT/CERU