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000
FXUS61 KCTP 161703
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1255 PM EDT SUN MAR 16 2014

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL TRACK WELL TO THE SOUTH OF PENNSYLVANIA
TONIGHT AND MONDAY. THE NORTHERN EDGE OF ITS SNOW SHIELD WILL BRUSH
FAR SOUTHERN PENNSYLVANIA...BRINGING LIGHT SNOW ACCUMULATIONS NEAR
AND TO THE SOUTH OF THE PENNSYLVANIA TURNPIKE. HIGH PRESSURE WILL
BUILD SE ACROSS THE REGION LATE MONDAY AND TUESDAY. ANOTHER LOW
PRESSURE SYSTEM WILL LIKELY TRACK WEST OF PENNSYLVANIA BY MIDWEEK.

&&

.NEAR TERM /UNTIL 8 PM THIS EVENING/...
HIGH PRESSURE OVER THE GRT LKS AND ASSOCIATED ARCTIC AIRMASS IS
NUDGING SOUTHWARD INTO FAR SOUTHERN PENN AT MIDDAY. BASED ON A QUICK
DROP OF SFC DEWPOINTS BY 8-10F OVER THE PAST FEW HOURS ACROSS
CENTRAL SRN PENN...THE LEADING EDGE OF THIS WEDGE OF MUH COLDER AIR
APPEARS TO BE RIGHT NEAR THE MASON DIXON LINE AT 16Z.

THICKENING CLOUD COVER AND THE LLVL CAA THIS AFTERNOON WILL MUTE THE
EFFECTS OF THE RELATIVELY STRONG MID MARCH SUN...AND ALLOW TEMPS TO
RISE JUST ANOTHER FEW DEG F.

LIGHT SNOW IS SLIGHTLY AHEAD OF THE 12Z NAM/S DEPICTION OF THE NE
LEADING EDGE ACROSS WVA. THEREFORE...HAVE MADE SOME MINOR
ADJUSTMENTS TO THE ONSET TIME ACROSS THE LAURELS - TO THE 21-22Z
TIMEFRAME. LIGHT SNOW WILL SPREAD ACROSS FAR SCENT PENN AND INTO THE
LOWER SUSQ VALLEY BETWEEN 22Z-00Z.


MAX TEMPS /LIKELY OCCURRING BETWEEN 18-19Z TODAY/ WILL RANGE FROM
ONLY ARND 20F OVR THE NW MTNS...TO PERHAPS THE U30S IN THE VALLEYS
ALONG THE MD BORDER.

&&

.SHORT TERM /8 PM THIS EVENING THROUGH 6 PM MONDAY/...
SOUTHERLY FLOW AHEAD OF LOW WILL DRAW ABUNDANT GULF OF MEX
MOISTURE NORTHWARD...OVERRUNNING COLD/DRY AIR MASS ENTRENCHED ACROSS
THE MID ATLANTIC REGION. LATEST 12Z OPERATIONAL GUIDANCE AND 06Z-09Z
GEFS AND SREF DATA CONTINUE TO CLEARLY TARGET AREAS SOUTH OF PA
FOR THE HEAVIEST PRECIP FROM THIS STORM...WITH EASTERLY WIND
ANOMALIES FOCUSED SOUTH OF THE MASON DIXON LINE TONIGHT AND EARLY
MONDAY. THAT BEING SAID...A BLEND OF LATEST SREF/GEFS AND
OPERATIONAL NAM/GFS STILL SUPPORTS POPS CLOSE TO 100 PCT TONIGHT
FROM AROUND THE TURNPIKE SOUTHWARD...WITH A CHC OF SOME LIGHT SNOW
AS FAR NORTH AS I-80.

BLENDED QPF FROM ENSEMBLE DATA AND LATEST OPER RUNS SUPPORT A LIGHT
SNOWFALL OF 1-2 INCHES ACROSS THE SOUTHERN 1-2 LAYER OF COUNTIES IN
PA...WITH PERHAPS SOME LOCALIZED 3-4 INCH AMOUNTS ALONG THE MD
BORDER /ESPECIALLY ACROSS THE HIGHER TERRAIN OF SOMERSET COUNTY/.
HOWEVER...DEEPER DRY AIR ENTRENCHED ACROSS THE NORTHERN HALF OF PA
SHOULD RESULT IN A RAPID DROP OFF IN ACCUMS NORTH OF THE TURNPIKE.
HAVE OPTED TO STILL HOLD OFF FROM ISSUING ANY WINT WX ADVISORIES
ATTM.

WAVE OF LOW PRESSURE WILL BE PASSING OFF THE EAST COAST ON
MONDAY...BRINGING AN END TO ANY LGT SNOW ACROSS SOUTHERN PA BY
AFTN. DESPITE BRIGHTENING SKIES...TEMPS WILL LIKELY GET NO WARMER
THAN THE 30S...AS HIGH PRES PARKED NR LK ONTARIO FUNNELS COLD AIR
SOUTHWARD INTO PA.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
BULK OF MDL GUIDANCE TRACKS TRAILING SOUTHERN STREAM SHORTWAVE
WELL OFF THE EAST COAST TUES/TUES NIGHT. 00Z NAM IS AN OUTLIER
ATTM...WITH A MUCH STRONGER/FURTHER WESTWARD TRACK OF LOW...SO NOT
GIVING MUCH WEIGHT TO THIS SOLUTION...WHICH WOULD IMPLY SIGNIFICANT
RAIN/MIXED PRECIP FOR SE PA. FAIRLY LITTLE SPREAD AMONG MED RANGE
GUIDANCE WITH TRACK OF LOW PASSING WEST OF PA WED. COLD HIGH PARKED
OVR NEW ENG COULD SET UP A COLD AIR DAMMING SCENARIO WITH THE
POSSIBILITY OF AN INITIAL PERIOD OF ICE/SNOW ACROSS THE
CENTRAL/NORTHERN MTNS BEFORE A CHANGE TO RAIN.

ANOTHER SHORTWAVE TRACKING ALONG THE NORTHERN CONUS WILL LIKELY
AFFECT CENTRAL PA BY LATE IN THE WEEK. INCREASING MDL SPREAD MAKES
TIMING OF THIS FEATURE A BIT TOUGHER...SO HAVE INCLUDED A CHC OF
RAIN/SNOW SHOWERS FRIDAY THRU EARLY SATURDAY. ECMWF ENSEMBLE MEAN
8H TEMPS IMPLY A RETURN TO NEAR NORMAL TEMPS THU-SAT AFTER A
CHILLY START TO THE WEEK.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
KBFD IS EXPERIENCING COMMS ISSUES...AND SHOULD BE FULLY BACK ON
LINE WITHIN 24 HRS. UNTIL THEN...WILL NOT BE ISSUING UNSCHEDULED
AMENDMENTS.

NORTHERLY FLOW /WITH LIMITED LLVL MOISTURE OFF LAKES ERIE AND
ONTARIO/ BEING FORCED OVER HIGHER TERRAIN OF NORTHERN PA IS
PRODUCING A BKN MVFR STRATOCU DECK EARLY THIS AFTERNOON. THIS SHOULD
SLOWLY MIX OUT/LIFT THROUGH THIS AFTERNOON.

ELSEWHERE...VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE DAY
AS LOWERING AND THICKENING /MAINLY MID LEVEL/ CLOUDS MOVE EAST
ACROSS PA AHEAD OF AN APPROACHING STORM SYSTEM. NORTHERLY SFC WIND
SPEEDS WILL BE AROUND 8-10 KTS WITH SOME GUSTS INTO THE MID TEENS.

THE STORM SYSTEM WILL SLIDE ACROSS MID ATLANTIC REGION OVERNIGHT
INTO MONDAY...WITH LIMITED IMPACTS IN PA. CENTRAL AND NORTHERN
SECTIONS WILL REMAIN VFR WHILE SOUTHERN PORTIONS OF CWA FROM KJST-
KAOO-KMDT-KLNS WILL LIKELY SEE SLIGHT REDUCTIONS TO VSBY IN LIGHT
SNOW ALONG WITH MVFR CIGS...ESP IN THE SE. TIMING LOOKS TO BE FROM
AROUND 02Z-14Z.

RESTRICTIONS AGAIN POSS TUE NIGHT INTO WED AS ANOTHER WEAK SYSTEM
MOVES THROUGH.


OUTLOOK...

MON...MVFR EARLY SOUTH. OTHERWISE VFR.

TUE...MAINLY VFR. CIG RESTRICTIONS POSS IN LAUREL HIGHLANDS.

TUE NIGHT-WED...PERIODS OF MVFR TO IFR ALONG WITH SCTD RAIN/SNOW
SHOWERS AS A FRONTAL SYSTEM MOVES THROUGH THE REGION.

THU...MVFR POSSIBLE IN THE MOUNTAINS. VFR OVER CENTRAL AND EASTERN
AREAS.

&&

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

&&

$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...LAMBERT/RXR