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000
FXUS61 KCTP 091254
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
754 AM EST MON DEC 9 2013

.SYNOPSIS...
LIGHT FREEZING RAIN OR FREEZING DRIZZLE WILL PERSIST INTO MID
MORNING BEFORE TEMPERATURES MODERATE TO ABOVE FREEZING IN MOST
AREAS BY LATE MORNING. AFTER A SLIGHT MODERATION IN TEMPERATURES
THIS AFTERNOON...GRADUALLY COLDER AIR WILL PUSH INTO THE STATE DURING THE
WEEK AS A PAIR OF COLD FRONTS TRACKS QUICKLY SOUTHEAST FROM THE
UPPER MIDWEST AND GREAT LAKES REGION.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
GENTLE WSWRLY ISENTROPIC WITH WIDESPREAD/LAYERED CLOUD
COVER AND PERSISTENT FREEZING DRIZZLE AND PERIODS OF LIGHT FREEZING
RAIN CONTINUE OVER MOST OF CENTRAL PA EARLY TODAY. THIS IS
PRODUCING A DANGEROUS GLAZE ON UNTREATED SURFACES. AREAS OF LIGHT
RAIN ARE SCATTERED ACROSS THE SOUTHERN HALF OF CENTRAL PA ON THE
NORTHERN PERIPHERY OF A MOIST PLUME EXTENDING FROM THE CENTRAL
GULF COAST THROUGH THE CENTRAL APPALACHIANS TO THE NORTHERN MID
ATLANTIC COAST. THE STEADIEST AND HEAVIEST RAINFALL HAS REMAINED
SOUTH OF THE MASON DIXON LINE OVERNIGHT...BUT SOME HOURLY AMOUNTS
OF .01 TO .02" HAVE PRODUCED ADDITIONAL ICING ACROSS THE SOUTHERN
THIRD OF CENTRAL PA OVERNIGHT...WITH .1 TO .2" OF ICE NEAR THE MD BORDER.

TEMPS WILL MODERATE TO NEAR AND ABOVE FREEZING BY LATE
MORNING...BRINGING AN END TO ANY LINGERING FREEZING DRIZZLE AND
FREEZING RAIN. CURRENT WINTER WEATHER ADVY EXTENDING THROUGH 15Z
LOOKS TO BE IN GOOD SHAPE.

COLD ADVECTION WILL INCREASE THIS AFTERNOON BRINGING FALLING
TEMPERATURES ACROSS THE WEST. AS MENTIONED YESTERDAY... A
NORTHWEST DOWNSLOPING FLOW SHOULD ALLOW TEMPS TO RISE INTO THE
LOWER 40S SOUTHEAST AND MID TO UPPER 30S ELSEWHERE. SCT --SHSN
WILL DEVELOP AS THE COLD AIR RUSHES IN OVER THE NW THIS AFTN.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
A TRICKY FORECAST IN STORE FOR LATE TONIGHT AND TUESDAY AS ANOTHER
FAST MOVING UPPER WAVE RACES TO THE MID ATLANTIC COAST INDUCING AN
AREA OF LIGHT SNOW TO BREAK OUT AND TRACK ACROSS CENTRAL AND
ESPECIALLY SOUTH CENTRAL PA. AN IMPRESSIVE JET ENTRANCE REGION
SETS UP ACROSS SOUTH CENTRAL AND ESPECIALLY SOUTHEAST PA ON
TUESDAY...AS A 180 KT 250 MB JET PROPOGATES OFF OF THE SOUTHERN
NEW ENGLAND COAST BY LATE IN THE DAY.

OUR GRIDS CONTAIN A FEW INCHES OF ACCUM OVER THE SOUTHEAST... BUT
SUCH STRONG JET DYNAMICS MAY ARGUE FOR LOCALLY HIGHER AMOUNTS AND
THIS WILL BE THE PRIME FORECAST PROBLEM AFTER THE MORNING FREEZING
DRIZZLE AND FREEZING RAIN SUBSIDES. IN THE MEANTIME...LAKE EFFECT
REGIME WITH LITTLE MORE THAN SCATTERED -SHSN IS EXPECTED
LATE TONIGHT ACROSS WESTERN AND NORTHERN SECTIONS. MINS WILL DROP
TO THE MID TEENS NORTHWEST TO THE MID 20S SOUTHEAST.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
AS THE AFOREMENTIONED SYSTEM PULLS EAST TUESDAY NIGHT AND WEDNESDAY...
ARCTIC AIR SURGES INTO THE REGION FOR THE REST OF THE WORK WEEK.
NORTHWEST FLOW ALOFT AND AROUND BUILDING HIGH PRESSURE AT THE
SURFACE WILL BRING LOWS IN THE SINGLE DIGITS AND TEENS FOR THU AND
FRI MORNING...AND HIGHS MAINLY IN THE 20S.

THIS WEEKEND...FLOW TURNS WESTERLY BRINGING GRADUAL MODERATION TO
TEMPERATURES. ANOTHER WAVE OF LOW PRESSURE PROGGED FOR LATER SAT
INTO SUNDAY WITH LIGHT PRECIPITATION POSSIBLE.

&&

.AVIATION /13Z MONDAY THROUGH FRIDAY/...

ONLY SCATTERED PRECIPITATION REMAINS DUE TO MOIST SERLY FLOW
RIDING OVER COLD AIR AT GROUND LEVEL. THIS WILL CONTINUE TO PRODUCE
PERIODS OF FZDZ ACROSS MUCH OF CENTRAL PA THROUGH MID MORNING. AN AREA
OF LOW PRESSURE PASSING SOUTH OF THE STATE WILL PRODUCE A SOMEWHAT
HEAVIER PERIOD OF FZRA ACROSS THE THE SOUTHEAST PART OF THE STATE.  APART
FROM THE FREEZING PRECIP...WIDESPREAD IFR/LIFR CIGS APPEAR ALMOST
CERTAIN THROUGH 18Z...AS THE INCREASINGLY MOIST SE FLOW ASCENDS
THE HIGHER TERRAIN OF CENTRAL PA.

LATEST MDL DATA INDICATES THE FZRA/FZDZ WILL TAPER OFF BY LATE AM...AS
THE LOW PRESSURE SYSTEM PASSES OFF THE E COAST. AS THE SFC
TEMPERATURES WARM...THERE SHOULD BE SOME LATE MORNING...EARLY
AFTERNOON RAIN FOR MDT AND LNS. AFTER 15Z TO 19Z EXPECT IMPROVING
FLYING CONDS AS SHIFTING WINDS TO THE WEST USHER IN DRIER AIR. THE
SCATTERED SHOWERS SHOULD END THROUGH THIS TIME PERIOD. RESIDUAL
LOW LVL MOISTURE ASCENDING THE W MTNS COULD POTENTIALLY ALLOW LOWS
CIGS TO PERSIST AT KBFD AND KJST THIS EVENING.

OUTLOOK...
TUE...AM SNOW/LOW VSBYS POSSIBLE...MAINLY SOUTH.
WED...SHSN/LOW VSBYS POSSIBLE AT KBFD.
THU-FRI...NO SIG WX EXPECTED.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-
049>053-056>059-063>066.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...RXR/TYBURSKI
AVIATION...FITZGERALD/CERU