Area Forecast Discussion
Issued by NWS State College, PA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
082
FXUS61 KCTP 010215
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1015 PM EDT SAT APR 30 2016

.SYNOPSIS...
A LARGE LOW PRESSURE AREA OVER THE CENTRAL U.S. WILL MOVE EAST
OVER THE NEXT FEW DAYS. EXPECT A PROLONGED PERIOD OF UNSETTLED
WEATHER THROUGH AT LEAST EARLY MONDAY WHEN THE LOW WILL REDEVELOP
ALONG THE MID ATLANTIC COAST AND MOVE OFFSHORE. DAMP CONDITIONS
WILL CONTINUE NEXT WEEK WITH SEVERAL CHANCES FOR RAIN.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
THE RAIN CONTINUES ON SCHEDULE AND COVERS ALL BUT THE EXTREME EAST
AS OF 930 PM. IT WILL CONTINUE NORTHEASTWARD THROUGHOUT THE
EVENING AND OVERNIGHT.

THE MOST INTENSE PERIOD OF WARM ADVECTION/ISENTROPIC LIFT WILL BE
FROM ABOUT LATE EVENING THROUGH SUNRISE AS THE NOSE OF THE LLJ
PUNCHES THROUGH CENTRAL PA.

ONLY NEEDED TO MAKE MINOR TWEAKS TO THE POPS GIVEN THE
TIMING...AND WORD-SMITHED A BIT TO CALL FOR PERIODS OF RAIN.
OTHERWISE FORECAST REMAINS ON TRACK FOR A RAINY NIGHT ACROSS THE
COMMONWEALTH.

OVERNIGHT LOWS GENERALLY IN THE MID TO UPPER 40S WILL AVERAGE
ABOUT 5-10 DEG ABOVE NORMAL.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
THE WAVE GENERATING THE RAIN WILL BE GETTING TO THE EAST OF OUR
LATITUDE IN THE MORNING...BUT RAIN WILL CONTINUE FOR AT LEAST THE
MORNING IN THE EASTERN HALF OF THE AREA. THE WARMER AIR WILL TRY
TO WORK DOWN TO THE SFC DURING THE DAY/AFTN BUT RESIDUAL MOISTURE
MAY KEEP LOTS OF LOW CLOUDS IN PLACE. RAINFALL BY NOON WILL BE
INTO THE 0.5 TO 1 INCH RANGE. THE LOW WILL MOVE INTO OH AND NW PA
ON SUNDAY...OCCLUDING IT/S COLD AND WARM FRONTS AS IT DOES SO. A
SECOND WAVE OF DECENT LIFT WILL COINCIDE WITH THE TRIPLE POINT
INCHING INTO CENTRAL PA SUNDAY EVENING. WE WILL LIKELY BE IN AN
AREA OF NVA AND DRYING ALOFT. SO FOR A WHILE IN THE DAYTIME ON
SUNDAY...WE SHOULD BE IN A LULL. HOWEVER...IF SOME BREAKS CAN
DEVELOP AND SOME MEAGER FORCING PASS OVERHEAD...WE MAY BE ABLE TO
POP A FEW TALL SHRA/SHORT TSRA. BUT THE HEIGHTS WILL NOT HAVE
FALLEN MUCH BY THAT TIME...AND THE CLOUD COVER MAY BE STICKING
TIGHT. THE WARM SECTOR DOES GET RATHER CLOSE...THOUGH. THE WARM
FRONT WILL BE BARELY INTO OR WILL BE HALTING AT THE
LAURELS/ALLEGHENIES. THUS...LLVL SHEAR COULD BE MAXIMIZED THERE. A FEW
ROTATING STORMS ARE POSSIBLE WITH LOWERED BUT PROBABLY ELEVATED
INSTABILITY IN THAT S/W REGION. DUE TO THE PRESENCE OF ELEVATED
INSTABILITY AND POSSIBILITY OF MIXING ACROSS THE REST OF THE
AREA...WILL KEEP CHC/SCT TS IN THE FCST FOR THE AFTN/EVENING.

MAXES WILL BE VERY MUCH DEPENDENT UPON THE AMOUNT OF SUNSHINE
WHICH CAN BREAK THROUGH. A WARM START TO THE DAY WILL HELP US BUT
THE PERSISTENT CLOUDS - ESP IN THE E - WILL LIMIT THE RISE. WILL
GO WITH MAXES ONLY 5-6F HIGHER THAN MORNING TEMPS IN THE
EAST...BUT MORE LIKE 10 OR 12F RISE IN THE WEST. THE WARM AIR MAY
PUSH INTO THE AREA A BIT MORE OVERNIGHT...SO TEMPS SHOULD NOT FALL
PAST THE U40S AND M50S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
RAIN WILL COME TO AN END AROUND MIDDAY MONDAY AS MAIN WAVE LIFTS
INTO NEW ENGLAND. 48-HOUR FORECAST RAINFALL TOTALS ENDING 00Z
TUESDAY ARE AROUND 1.00 NORTH TO 1.25 INCHES SOUTH...WITH HIGHER
AMOUNTS OVER THE WESTERN ALLEGHENIES AND SOUTHERN TIER COUNTIES
WHERE MARGINAL INSTABILITY MAY ALLOW FOR CONVECTIVE ENHANCEMENT.
THE FCST RAINFALL SHOULD HELP THE AREA RECOVER FROM /60-90+ DAY/
DEFICITS GENERALLY ON THE ORDER OF -2.00 TO -4.00 INCHES. THE
LATEST DROUGHT MONITOR NOW HAS OVER HALF OF PENNSYLVANIA IN
ABNORMALLY DRY /D0/ CONDITIONS WITH A SMALL AREA OF MODERATE
DROUGHT /D1/ CONDITIONS FOCUSED OVER BEDFORD COUNTY.

A PERIOD OF IMPROVING/DRY WEATHER IS LIKELY FROM MONDAY AFTERNOON
THROUGH TUESDAY BEFORE THE PATTERN TURNS QUITE UNSETTLED INTO THE
MIDDLE AND SECOND HALF OF NEXT WEEK. THE GLOBAL ENSEMBLE MEANS ALL
SHOW AN AMPLIFIED/ANOMALOUS MEAN UPPER TROUGH DEVELOPING AND
SETTLING IN OVER THE ERN CONUS...WITH THE ECMWF A BIT DEEPER AND
HOLDING ENERGY A BIT FURTHER WEST WHILE THE GFS POSITIONS A BIT
MORE TO THE EAST. INTERESTINGLY...THE 12Z RUNS BOTH HAVE A 544DM
500MB LOW OVER E PA NOW AT 00Z SUN...SO MAYBE A GLIMPSE OF
INCREASING CERTAINTY WORKING INTO THE SOLUTIONS.

AT THE SURFACE...ECMWF AGAIN MORE AGGRESSIVE WITH AREA OF LOW
PRESSURE OVER MID ATLANTIC BACKING INTO PA ON THU WHILE GFS BRINGS
A WEAKER LOW ALONG SAME PATH FRI INTO SAT /EC ALSO SHOWS THIS AS
AS SECOND WAVE/. SO THOUGH PATTERN LOOKS QUITE UNSETTLED...
CONFIDENCE/PREDICTABILITY IN THE RAINFALL TIMING AND COVERAGE
PATTERN REMAINS ON THE LOWER SIDE. DID FOCUS HIGHEST POPS ON THE
THU-FRI PERIOD WITH THE UPPER CLOSED LOW AND SURFACE LOW
STACKING...WHICH WILL ALSO BE POTENTIAL FOR HEAVIEST RAIN THIS
PERIOD. OTHERWISE IT LOOKS LIKE A CLOUDY AND WET WEEK WITH
PERIODS OF GENERALLY LIGHT PRECIPITATION AND RELATIVELY COOL
TEMPERATURES VS. SEASONAL CLIMATOLOGY.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
LOW PRESSURE APPROACHING THE OHIO VALLEY TONIGHT WILL SUPPORT
PERIODS OF MAINLY LIGHT RAIN ACROSS THE AIRSPACE INTO THE DAYLIGHT
HOURS OF SUNDAY MORNING. EXPECT THE WORST PERIOD OF CIGS/VIS IN
THE OVERNIGHT UNTIL A FEW HOURS AFTER SUNRISE ON SUNDAY. WARM
FRONT EXTENDING IN FROM THE MAIN LOW WILL TRY TO LIFT INTO THE
CENTRAL MTNS...BUT WILL LIKELY STALL OVER SWRN/WRN PA.
HOWEVER...SOME CLEARING IN THE DAYTIME COULD PRODUCE SCT SHRA/TSRA
ACROSS ALL OF THE AREA. THE MAIN THREAT AREA FOR TSRA IS VCTY
JST/AOO. A SECOND WIDE AREA OF RAIN/LOW CIGS/VIS WILL PUSH ACROSS
AS THE MAIN SFC LOW PUSHES THROUGH SUN NIGHT/EARLY MONDAY MORNING.
DRIER AIR WILL WORK IN FOR A VERY BRIEF TIME ON MONDAY. A WAVE
RIDING THROUGH THE DEEP SOUTH AND MID-ATLANTIC STATES ON TUESDAY
WILL PROBABLY SPREAD MORE RAIN INTO THE SE HALF OF THE AREA MON
NIGHT/TUES.

OUTLOOK...

MON PM-TUE...RA POSS SE.

TUE PM...NO SIG WX.

WED...SHRA POSS.

THU...IFR POSS IN RA/FG.

&&

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

&&

$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...DANGELO/GARTNER



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.