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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCTP 160712
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
312 AM EDT SUN JUN 16 2013

.SYNOPSIS...
AN AREA OF LOW PRESSURE OVER THE UPPER GREAT LAKES WILL MOVE
SOUTHEAST AND CROSS NEW YORK STATE LATER TODAY. THIS FRONT WILL BE
COVERED BY A NUMEROUS SHOWERS...AND SCATTERED THUNDERSTORMS.
ANOTHER WAVE OF LOW PRESSURE WILL ROLL EAST THROUGH THE APPALACHIANS
ON TUESDAY. GENERALLY DRY WEATHER WILL FOLLOW FOR THE SECOND HALF OF
THE WEEK AS A LARGE AREA OF HIGH PRESSURE BUILDS SOUTHEAST FROM THE
UPPER MIDWEST.

&&

.NEAR TERM /UNTIL 10 AM THIS MORNING/...
INCREASING WARM ADVECTION /WITH THE WESTERLY ISENTROPIC LIFT
FOCUSED WITHIN THE 300-310K THETA CHANNEL/ WILL SUPPORT AN EASTWARD
EXPANDING AREA OF ALTO CU/AND PERHAPS SOME LOWER STRATOCU OR HIGH NS
CLOUDS THROUGH THE EARLY MORNING HOURS TODAY. SCATTERED...MAINLY
LIGHT SHOWERS FALLING FROM THIS CLOUD DECK WILL LIMITED TO MAINLY
THE WESTERN MTNS.

RAINFALL AMOUNTS WILL BE GENERALLY LESS THAN ONE-TENTH OF AN INCH
THROUGH DAYBREAK...AND MORE LIKELY JUST A FEW HUNDREDTHS IN MOST
SPOTS.

MIXED-LAYER...AND EVEN ELEVATED INSTABILITY AHEAD OF A WARM FRONT
WILL BE NIL FOR THE REST OF THE OVERNIGHT...SO NO THUNDER WILL BE
INCLUDED IN THE FCST EARLY TODAY.

ACROSS THE EASTERN HALF OF THE CWA...AREAS OF ALTO CU AND SOME THIN
CIRRUS WILL PREVAIL...WITH JUST A SLIGHT CHANCE OF A LIGHT SHOWER
TWD DAYBREAK TO THE WEST OF THE SUSQ MAINSTEM.

LOW TEMPS EARLY THIS MORNING WILL VARY FROM THE LOWER 50S ACROSS
PORTIONS OF THE NRN MTNS...TO THE UPPER 50S THROUGHOUT THE SOUTHERN
VALLEYS AND SUSQ VALLEY.

WINDS WILL AVERAGE 5 KTS OF LESS FROM THE WEST TO SOUTHWEST.

&&

.SHORT TERM /10 AM THIS MORNING THROUGH 6 PM MONDAY/...
-- Changed Discussion --
18Z GEFS AND 21Z SREF IMPLY THAT PWATS AND 850 MB MOISTURE FLUX WILL
INCREASE RAPIDLY FROM WEST TO EAST DURING THE DAY TODAY...
SUPPORTING BOTH ADVECTION AND DEVELOPMENT OF NUMEROUS SHOWERS AND
TSRA ACROSS THE FCST AREA.

THIS STRENGTHENING OF THE LLVL WSW WINDS...RAPIDLY INCREASING
MOISTURE FLUX AND DECENT AFTERNOON INSTABILITY WILL BRING THE
POTENTIAL FOR SOME MODERATE RAINFALL AMOUNTS OF 0.50-0.75 OF AN INCH
IN SOME LOCATIONS BY THIS EVENING.

MORNING AND EARLY AFTERNOON CONVECTION AND EXTENSIVE CLOUD COVER
SHOULD HAMPER THE HEATING AND  KEEP TEMPS A FEW DEGS COOLER THAN
SAT/S MAXES. THE HEAT OR LACK THEREOF WILL BE THE BIGGEST DETRIMENT
TO STRONG STORMS ON SUNDAY AFTERNOON. THE FLOW IS ALSO MAINLY
UNIDIRECTIONAL AND UP TO 40 KTS WITHIN 2 KFT AGL. ANY STORMS COULD
EASILY MIX DOWN THIS MOMENTUM TO THE SFC IN GUSTS OF 35 TO 45 KTS.
HOWEVER...CONFIDENCE AT THIS POINT IS NOT HIGH ENOUGH TO INCLUDE ANY
ENHANCED WORDING INTO THE FCST OR HWO.

WEAK RIDGING BUILDING IN FROM THE OHIO VALLEY MONDAY WILL BE
ACCOMPANIED BY A NEARLY EAST/WEST RIBBON OF NEG THETA-E ADVECTION
IN THE LOW-MID LEVELS.

THE CLOSE PROXIMITY OF THE WASHED OUT LLVL BOUNDARY NEAR OR JUST
SOUTH OF THE MASON/DIXON LINE...AND THE APPROACH OF
ANOTHER/STRONGER CFRONT /AND QUITE STEEP MID-LEVEL LAPSE RATES/
MOVING IN FROM THE NW LATE MONDAY MONDAY NIGHT WILL PREVENT US
FROM COMPLETED PULLING MENTION OF ISOLATED SHRA/TSRA FROM THE FCST
FOR MONDAY. HOWEVER...AT THIS TIME CHC FOR CONVECTION APPEAR QUITE
LOW.

TEMPS MONDAY WILL TOP OUT A FEW DEG F ABOVE NORMAL...WITH HIGHS
RANGING FROM THE UPPER 70S ACROSS THE MTNS...TO THE MID 80S IN THE
SOUTHEAST.
-- End Changed Discussion --

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
-- Changed Discussion --
BROAD TROUGH OVER NORTHEAST U.S. WILL BRING AN UNSETTLED START TO
THE WEEK...BUT RIDGE BUILDING IN STARTING MIDWEEK WILL BRING DRY
WEATHER FOR LATTER PORTION OF THE WORK-WEEK.

FRONTAL BOUNDARY WILL BE MEANDERING NEAR THE MASON/DIXON LINE
MONDAY NIGHT AS WINDS TURN WESTERLY /PARALLEL TO FRONT/...
CONTINUING HIGHEST POPS ACROSS SOUTHERN PORTION OF CWA.

THIS FRONT WILL LIKELY DRIFT BACK NORTH A BIT /INTO SOUTHERN OR
CENTRAL PENN/ FOR TUESDAY AS ONE OR MORE FAST MOVING WAVES ALOFT
SLIDE EAST ACROSS THE REGION.

DECENT MID LEVEL LAPSE RATES IN EXCESS OF 6C/KM WILL EXIT EAST OF
THE CWA LATE TUESDAY...BUT NOT BEFORE SUPPORTING A FEW ROUNDS OF
SHOWERS AND THUNDERSTORMS DURING THE DAY.

NORTHERLY FLOW DEVELOPS TUE NIGHT INTO WED AS HIGH PRESSURE
BUILDS SOUTHWARD ACROSS GLAKES...WHICH WILL KICK THE FRONTAL
BOUNDARY FURTHER SOUTH AND USHER IN BEGINNING OF A PERIOD OF
DRIER AND SLIGHTLY COOLER WEATHER /ABOUT 5F BELOW NORMAL/.

WE/LL SEE A FEW CHILLIER NIGHTS ACROSS THE NORTH /ESP WED NIGHT/
AS HIGH SETTLES IN. BUT SOUTHWESTERLY RETURN FLOW BEGINS ON THU.
AS LOWER LEVELS BEGIN TO SLOWLY MOISTEN BACK UP...ISOLATED LATE
DAY TSTMS AGAIN BECOME POSSIBLE OVER SOUTHERN HALF THU AND ESP
FRI.

HEIGHTS RISE HEADING INTO THE WEEKEND...AND REGION WILL SEE A WARM
UP WITH HIGHS IN THE 80S AREA-WIDE. SURGE OF MOISTURE ALSO GETS
PUSHED FROM THE CENTRAL U.S. TOWARD THE EAST COAST THIS
WEEKEND...BRINGING INCREASINGLY HUMID CONDITIONS AND GROWING
CHANCES FOR TSTORMS...ESP NEXT SUNDAY.
-- End Changed Discussion --

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL CONTINUE OVERNIGHT AT ALL LOCATIONS. ANY
SHOWERS THAT ARE MOVING INTO CENTRAL PA HAVE BEEN DISSIPATING AND
ONLY BEEN REPRESENTED IN THE FORM OF A MID LEVEL CLOUD DECK.
HOWEVER SOME WEAK SHOWERS COULD BRIEFLY AFFECT BFD...JST OR AOO.
MODELS SHOWING THAT REMNANTS OF IL/IN CONVECTION WILL MOVE INTO
WESTERN AREAS EARLY THIS MORNING. THIS AREA OF MAINLY SHOWERS WILL
SLIDE EAST WITH A SECOND ROUND OF PRECIPITATION EXPECTED TO DEVELOP AHEAD
OF AN APPROACHING COLD FRONT. THERE COULD BE SOME EMBEDDED
TSRA...HOWEVER IT IS DIFFICULT TO PINPOINT IN TAFS ATTM FOR
THIS AFTERNOON. SO HAVE LEFT ONLY SHOWERS IN AND THERE IS A
POSSIBILITY FOR VCTS/TSRA THIS AFTERNOON.

TONIGHT AND MONDAY SHOULD SEE A GENERAL DECREASE IN PRECIPITATION
AS THE FRONT SETTLES SOUTH OF PENNSYLVANIA...BUT SCATTERED
SHRA/TSRA WILL LINGER.

OUTLOOK...
MON...VALLEY FOG POSS IN AM...THEN MAINLY VFR...BUT WITH SCATTERED
CONVECTION AND POSSIBLE RESTRICTIONS.
.TUE...SCT RESTRICTIONS POSSIBLE IN SHOWERS AND THUNDERSTORMS.
WED-THU...NO SIG WX.

&&

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

&&

$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...RXR
AVIATION...JUNG/CERU