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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCTP 161309
AFDCTP

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

.SYNOPSIS...
-- Changed Discussion --
AN AREA OF LOW PRESSURE OVER LAKE HURON WILL MOVE TO THE EAST
TODAY. A COLD FRONT WILL DRAG ACROSS CENTRAL PENNSYLVANIA THIS
AFTERNOON AND EVENING. 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 INTO THE REGION FROM THE UPPER MIDWEST.
-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 7 PM THIS EVENING/...
-- Changed Discussion --
COLD FRONT POISED OVER LOWER MICHIGAN AND NRN INDIANA MOVING
SOUTHEAST AS EXPECTED. WARM ADVECTION CONTINUES TO FORCE LARGE-
SCALE LIFT AND WIDESPREAD CLOUDS/OCNL SHOWERS OVER THE WEST AND
NORTH. THE 9 AM RADAR MOSAIC SHOWS A LARGE AREA OF SHOWERS SANS
THUNDER MOVING THROUGH WESTERN PA AND MOST OF OHIO. THESE CLOUDS
CONTINUE TO BE THE BIGGEST DRAWBACK TO DESTABILIZATION FOR TODAY.
WILL THEREFORE KEEP THE FORECAST AS IS WITHOUT MUCH FANFARE. IN
FACT...WE MAY BE PLAYING UP THE POSSIBILITY OF THUNDER UNLESS
THERE IS A BIG BREAK OF CLEARING JUST BEFORE THE FRONT COMES
ACROSS...WHICH IS STILL A POSSIBILITY LOOKING AT THE VIS SAT PICS
THIS MORNING OVER DTX AND ERI. WILL JUST NUDGE MAXES DOWN A DEG
OVER MOST OF THE AREA FOR THE CLOUD COVER.

MOST OF PREV DISC FOLLOWS...
WITH THE WESTERLY ISENTROPIC LIFT IS FOCUSED WITHIN THE 300-310K
THETA CHANNEL AND 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 SHOULD BE LIMITED TO MAINLY THE
WESTERN MTNS. HAVE INCREASED POPS SLIGHTLY ACROSS THE REGION TO
COVER ANY LIKELIHOOD OF ANY PRECIPITATION FALLING DUE TO THE
INCREASING AND SPREADING STRATOCU. THE LAYER IS WELL MIXED WITH A
GENERAL LACK OF ELEVATED INSTABILITY OUT AHEAD OF THE INCOMING
WARM FRONT. SO HAVE LEFT OUT ANY MENTION OF THUNDER THROUGH THE
MORNING HOURS.

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

TEMPERATURES 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.
-- End Changed Discussion --

&&

.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM MONDAY/...
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.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
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.

&&

.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
VFR CONDITIONS WILLCONTINUE THIS MORNING AT MOST LOCATIONS. THE
SHOWERS THAT ARE MOVING THROUGH CENTRAL PA SHOULD AFFECT BFD...JST
AND AOO. ANY PRECIPITATION WILL BE LIGHT BUT THERE ARE HEAVIER
BANDS MOVING THROUGH BFD THAT WILL CAUSE IFR CONDITIONS AT BFD FOR
A FEW HOURS...UNTIL 14Z. WITH MVFR FOR A FEW HOURS AT JST.

MODELS SHOWING THAT REMNANTS OF IL/IN CONVECTION WILL MOVE INTO
WESTERN AREAS OF THE REGION LATE MORNING. THIS AREA OF MAINLY
SHOWERS WILL SLIDE EAST WITH A SECOND ROUND OF PRECIPITATION
EXPECTED TO DEVELOP AHEAD OF AN APPROACHING COLD FRONT THIS
AFTERNOON. 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.
TUE...VFR BUT SCT RESTRICTIONS POSSIBLE IN SHOWERS AND
THUNDERSTORMS AREA-WIDE.
WED-THU...NO SIG WX.
-- End Changed Discussion --

&&

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

&&

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