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000
FXUS61 KCTP 180252
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1052 PM EDT MON JUN 17 2013

.SYNOPSIS...
A FEW WEAK SURFACE COLD FRONTS WILL DROP SOUTHEAST ACROSS THE
COMMONWEALTH TONIGHT AND TUESDAY...BRINGING GENERALLY SCATTERED
SHOWERS AND THUNDERSTORMS TONIGHT AND TUESDAY. GENERALLY DRY
WEATHER WILL FOLLOW FOR THE SECOND HALF OF THE WEEK AS A LARGE
AREA OF HIGH PRESSURE BUILDS INTO THE REGION. ABOVE NORMAL
TEMPERATURES WITH INCREASING HUMIDITY ARE EXPECTED FOR NEXT
WEEKEND AS WARM AIR FROM THE CENTRAL STATES MOVES TO THE EAST.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
FAIR WEATHER WILL CONTINUE ACROSS MUCH OF THE REGION UNTIL WELL
AFTER MIDNIGHT. WITHIN THE NEXT SEVERAL HOURS...WE/LL SEE AN
INCREASE IN SHOWERS AND TSRA ACROSS THE NW MTNS...THEN THE NCENT
MTNS AS A DISTINCT WAVE OF LOW PRESSURE /CURRENTLY OVER LAKE ERIE/
MOVES EAST ALONG A STALLED OUT FRONTAL BOUNDARY ACROSS THE
SOUTHERN TIER OF NEW YORK STATE.

THIS LOW WILL BE SUPPORTED BY A WELL DEFINED JET ENTRANCE REGION
100 KT WIND MAX AT 300 MB OVER LAKE ONTARIO AT 02Z/ THAT WILL BE
SLIDING EAST TOWARD THE I-81 CORRIDOR OF NEPA AND SOUTHERN NEW
YORK TOWARD DAYBREAK.

RAINFALL AMOUNTS OF A TENTH TO QUARTER OF AN INCH APPEAR LIKELY
ACROSS THE NW MTNS TONIGHT...WITH LESSER AMOUNTS FURTHER SE TWD
THE I99/ROUTE 220 CORRIDOR.

ELSEWHERE...VARIABLE AMOUNTS OF HIGH CLOUDS...WILL STREAM EAST
TONIGHT...FOLLOWED BY SOME ALTO CU VERY LATE TONIGHT.

LOW TEMPS TONIGHT WILL BE NEAR 50F ACROSS THE NORTHERN MTNS...AND
UPPER 50S TO LOWER 60S ACROSS THE SOUTH.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
THIS MAIN/THIRD FRONT SHOULD CONTINUE TO TREK THROUGH THE REGION ON
TUESDAY AND WILL MAKE THE POPS MUCH MORE WIDESPREAD/HIGHER. PWATS
REACH NEAR AN INCH AND A HALF ON TUES...WHICH COULD COMBINE WITH
SLOWLY MOVING CELLS TO MAKE A BRIEF HEAVY DOWNPOUR. BUT FFG VERY
HIGH AND THREAT FOR FLOODING VERY LOW. THIS FRONT...TOO...MAY WASH
OUT AS IT REACHES THE SRN BORDER.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
BROAD TROUGH OVER NORTHEAST U.S. WILL BRING UNSETTLED WEATHER
EARLY IN THE WEEK...THEN BUILDING RIDGE WILL BRING GENERALLY DRY
WEATHER FOR MID/LATE WEEK. HUMIDITY AND TEMPERATURES INCREASE
NOTICEABLY FOR NEXT WEEKEND ALONG WITH DAILY TSTM CHANCES.

AS ONE FRONTAL BOUNDARY WASHES OUT OVER MID ATLANTIC STATES...
ANOTHER FRONT IS PUSHED SOUTHWARD ACROSS CWA TUE INTO TUE NIGHT AS
SHORTWAVE ROTATES THROUGH BROAD TROUGH OVERHEAD. THIS WILL KEEP
MENTION OF SCT TSTMS IN FORECAST AT LEAST THROUGH TUE EVE.

THAT FRONTAL BOUNDARY WILL SIGNAL THE BEGINNINGS OF A PATTERN
CHANGE. BEHIND IT FOR WED...WINDS TURN NORTHERLY AS SURFACE HIGH
PRESSURE BUILDS IN ACROSS THE GREAT LAKES...WITH W-E RIDGE AXIS
SETTLING OVER PA ON THURSDAY. WE/LL SEE A FEW CHILLIER
NIGHTS...ESP ACROSS THE NORTH /THE COLDEST BEING WED NIGHT WITH
READINGS DIPPING INTO THE 40S NORTH OF I-80/. TEMPS MILDER ACROSS
THE SOUTH WHERE HIGHER DEWPOINTS WILL BE TOUGHER TO SCOUR OUT.

AS RIDGE CONTINUES TO SLIP TO THE SE...LIGHT SOUTHWESTERLY FLOW
DEVELOPS THU. MOISTURE WILL BE SLOW TO INCREASE THU AND FRI...BUT
WEAKENING CAP WILL LEAD TO INCREASING CHANCES FOR ISOLATED LATE
DAY TSTMS OVER SOUTHERN HALF.

LARGER RIDGE OVER CENTRAL U.S. BUILDS EASTWARD INTO OHIO VALLEY
THIS WEEKEND. HIGHER TEMPS AND DEWPOINTS WILL ADVECT EASTWARD
AROUND TOP OF THE RIDGE...ARRIVING IN PA ON SAT AND PERSISTING FOR
SEVERAL DAYS...KICKING OFF DAILY SCT TSTMS /MAINLY NW HALF/. WE/LL
ALSO LIKELY SEE DECAYING MCS/S TRYING TO SLIDE EASTWARD INTO PA
SUNDAY AND MONDAY MORNING. THIS PATTERN WILL PERSIST UNTIL NEXT
FRONT COMES THROUGH MIDWEEK NEXT WEEK.

&&

.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
REGIONAL RADAR LOOP THIS EVENING SHOWS SHRA/TSRA ACROSS THE LOWER
GRT LKS IN ASSOCIATION WITH A SLOW-MOVING COLD FRONT. AS THIS
FRONT WORKS SE...A LATE NIGHT SHRA IS POSSIBLE OVR NORTHERN PA.
HOWEVER...THE BIGGEST AVIATION CONCERN TONIGHT IS THE POSSIBILITY
OF FOG AT MDT AND LNS...WHERE RAIN HAS FALLEN LATE THIS AFTN.
MCLEAR SKIES...A LGT WIND AND WET GROUND ALL FAVOR DEVELOPMENT OF
FOG OVERNIGHT AT MDT AND LNS. HOWEVER...COMPLICATING FACTOR WILL
BE EXPECTED ARRIVAL OF CIRRUS SHIELD LATER TONIGHT IN ADVANCE OF
SHORTWAVE OVR THE MISS VALLEY. IF HIGH CLOUDS ARE THICK
ENOUGH...THEY COULD PRECLUDE FOG. AT THIS POINT...WILL TAKE A
MIDDLE GROUND FCST OF MVFR VSBYS AT MDT/LNS LATER TONIGHT.
HOWEVER...IFR IS A SLIGHT POSSIBILITY IF CIRRUS REMAINS THIN.

ANY FOG THAT MANAGES TO FORM OVERNIGHT SHOULD BURN OFF WITHIN A
COUPLE HRS AFTER SUNRISE. FOCUS WILL THEN SHIFT TOWARD SCT
SHRA/TSRA DEVELOPING TUES AFTN...AS COLD FRONT WORKS SOUTH ACROSS
THE STATE. ALTHOUGH VFR CONDS WILL PREDOMINATE...A BRIEF VSBY
REDUCTION IS POSSIBLE WITH ANY SHRA/TSRA.

OUTLOOK...
WED...EARLY AM LGT RAIN/LOW CIGS POSSIBLE JST/AOO.
THU...NO SIG WX EXPECTED.
FRI-SAT...ISOLD PM TSRA IMPACTS POSSIBLE.

&&

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

&&

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