Area Forecast Discussion
Issued by NWS State College, PA

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000
FXUS61 KCTP 280932
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
532 AM EDT THU APR 28 2016

.SYNOPSIS...
CLOUDS WILL THICKEN-UP FROM THE WEST EARLY THIS MORNING. AN AREA
OF LOW PRESSURE WILL RIPPLE ALONG A STATIONARY FRONT THAT WILL BE
LOCATED JUST TO THE SOUTH OF PENNSYLVANIA. THIS WEATHER FEATURE
WILL SPREAD RAIN OVER THE AREA TODAY...AND PERIODS OF LIGHT RAIN
OR DRIZZLE WILL CONTINUE TONIGHT INTO FRIDAY. SATURDAY WILL BE
MOSTLY CLOUDY AND COOL...BUT GENERALLY DRY BEFORE MORE RAIN MOVES
IN FOR SATURDAY NIGHT AND SUNDAY. RAIN COULD LINGER INTO LATE
MONDAY OR EARLY TUE.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A SHIELD OF MID AND HIGH CLOUDS WILL LOWER AND THICKEN AS IT
ADVANCES NORTHEAST ACROSS THE REGION EARLY TODAY. A WAVE OF
LOW PRESSURE DEVELOPING OVER THE MID MISS VALLEY THIS MORNING
WILL HEAD ENE UP THE OHIO RIVER VALLEY TODAY...AND BRING AN AREA
OF WARM ADVECTION/UVVEL UP AN OVER A QUASI STNRY BOUNDARY SITUATED
JUST SOUTH OF THE MASON/DIXON LINE. PERIODS OF COLD RAIN WILL BE
THE RESULT TODAY.

FOR THE REST OF THIS MORNING...LOOK FOR SOME PATCHY -DZ/SPRINKLES
(THAT WERE NOTED ON RADAR AND BEING REPORTED BY SPOTTERS) OVER
THE HIGH TERRAIN OF THE SC MTNS...WHERE UPSLOPE FLOW WAS RESULTING
IN RAP SFC-850 RH VALUES CLOSE TO 100 PCT.

THE LEADING EDGE OF AN AREA OF LIGHT TO BRIEFLY MDT RAIN WILL
OVERSPREAD THE THE SW HALF OF THE CWA LATE THIS MORNING ...AND
BEGIN IN THE 17-20Z TIMEFRAME ACROSS THE REGION NE OF KIPT PER A
BLEND OF THE LATEST 00Z OPER GUIDANCE...03Z SREF AND HRRR.

EARLIER THIN SPOTS IN THE CIRRUS SHIELD...ALONG WITH LGT NERLY SFC
WIND ALLOWED TEMPS TO DIP INTO THE 30S ACROSS THE NORTHERN
MTNS...WHILE READINGS IN THE M/U40S WERE COMMON ELSEWHERE.

BLENDED/CONSENSUS SHORT RANGE AND HIGH RES MODEL GUIDANCE
INDICATES THAT THE WARM FRONT WILL STAY JUST SOUTH OF PA...GIVEN
THE PROJECTED LOW LEVEL LIFTED INDICES PROGGED OVER THE
REGION...SO HIGHS WITH THE OFF AND ON RAIN SHOULD ONLY AVERAGE IN
THE LOW 50S...WELL BLW AVG FOR LATE APRIL.

BASED ON 18Z/00Z OPER AND LATEST 03Z SREF AND HRRR GUIDANCE...WILL
MAINTAIN HIGH 12 HOUR POP GRIDS - NEAR 100 PCT ACROSS THE AREA
TODAY. AGAIN..MOST OF THE RAIN SHOULD FALL DURING THE LATE AM
HOURS ACROSS THE SW COUNTIES...AND MAINLY DURING THE AFTN ACROSS
THE NE COUNTIES. BLENDED MODEL QPF INDICATING ARND A QUARTER INCH
OF RAIN IS LIKELY BY THIS EVENING.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
MOIST EAST TO SERLY LLVL FLOW WILL CONTINUE TONIGHT INTO FRIDAY
WITH PERIODS OF LIGHT RAIN AND DRIZZLE EXPECTED. ADDITIONAL
RAINFALL AMOUNTS DURING THIS 12 HOUR PERIOD SHOULD AVERAGE 1-2
TENTHS OF AN INCH IN MOST PLACES. HOWEVER...A FEW LOCATIONS COULD
SEE SLIGHTLY OVER ONE-QUARTER OF AN INCH.

LOW TEMPS EARLY FRIDAY WILL VARY FROM THE U30S ACROSS THE NRN
MTNS...TO THE LOWER 40S IN MOST OTHER PLACES.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
STILL LOOKS LIKE A SECOND WEAK SYSTEM WILL TRACK JUST SOUTH OF
THE AREA ON FRIDAY. THIS SYSTEM WILL LIKELY BRING A FEW MORE
SHOWERS TO THE AREA...AS AN INVERTED TROUGH SETS UP.

UNSEASONABLY COOL TEMPS WILL CONTINUE FOR FRIDAY...WITH HIGHS ONLY
IN THE U40S ACROSS THE HIGHEST ELEVATIONS OF THE NORTH...AND LOWER
TO MID ELSEWHERE.

MOST OF SAT STILL APPEARS DRY AS THE RIDGE EXTENDING FROM THE
CANADIAN HIGH REESTABLISHES ITSELF TEMPORARILY. SCATTERED SHOWERS
WILL MOVE INTO THE SW PART OF THE CWA LATE...WITH MORE NUMEROUS
SHOWERS FOR SAT NIGHT INTO SUNDAY.

OVERALL A PATTERN THAT FAVORS WETTER CONDITIONS AS WE MOVE
TOWARD THE KICKOFF OF MAY.

THE PERIOD FROM LATER SUNDAY INTO EARLY TUE WILL LIKELY RESULT
IN AT LEAST SOME RAIN AS A FAIRLY WELL-ORGANIZED AREA OF LOW
PRESSURE MOVES NE FROM THE OHIO RIVER VALLEY.

OVERALL NOT LOOKING REAL COLD...AS MAYBE THE GUIDANCE HINTED
AT THE OTHER DAY...BUT A WETTER PATTERN THAN WE HAVE SEEN LATELY.

THE SYSTEM FOR MONDAY LOOKS SIMILAR TO THE THU-FRIDAY SYSTEM.

DID NOT MAKE A LOT OF CHANGES...JUST MINOR. 06Z GFS WAS DRY
COMPARED TO THE 00Z EC. MAIN THING I DID WAS TO GO MAINLY
DRY LATER TUE...AND NOT REAL HIGH WITH POPS ON WED. SUPERBLEND
TEMPS FOR WED LOOK GOOD. THE LEADING EDGE OF THE REAL COLD AIR
WITH THE POLAR VORTEX NOT FAR AWAY...AS SECONDARY COLD FRONT WILL
BE OVER CENTRAL ONTARIO ON WED. THE 12Z GFS MORE IN LINE WITH
WITH KEEPING SOME RAIN ACROSS THE REGION FROM TIME TO TIME...AS
I HAVE SEEN LATELY.

INTERESTING TO NOTE...LAST MAY STARTED OFF WARM...NEW 12Z EC FOR
DAY 10 LOOKING MORE LIKE WINTER THIS YR.

&&

.AVIATION /09Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE WILL KEEP VFR CONDITIONS OVER THE NORTHERN AND MOST
CENTRAL PA TERMINALS OVERNIGHT. HOWEVER CALMER WINDS AND LOW
DEWPOINT DEPRESSIONS HAVE ALLOWED FOR LOW LEVEL STRATO CU TO FORM
OVER THE SOUTHERN VALLEY TAF LOCATIONS...AOO...MDT AND LNS. EXPECT
MVFR TO IFR CIGS AND VSBYS BETWEEN 07Z TO 12Z. THERE WILL BE A
BRIEF BREAK IN LOW CLOUDS HOWEVER MORE UNSETTLED WEATHER WILL
ARRIVE THURSDAY INTO FRIDAY AS AN AREA OF LOW PRESSURE MOVES OUT
OF THE OHIO RIVER VALLEY SLIDING BY JUST TO THE SOUTH OF
PENNSYLVANIA. THIS WILL BRING PERIODS OF RAIN AND MORE WIDESPREAD
IFR/MVFR TOMORROW AFTERNOON AND EVENING.

OUTLOOK...

FRI...MVFR WITH OCCASIONAL RAIN.

SAT...MAINLY VFR.

SUN-MON...WIDESPREAD MVFR/IFR WITH OCCASIONAL RAIN.

&&

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

&&

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


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