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000
FXUS61 KCTP 172215
AFDCTP

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

.SYNOPSIS...
A SERIES OF WEAK SURFACE FRONTS WILL CROSS THE COMMONWEALTH
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 11 PM THIS EVENING/...
SFC TROUGH/FRONT NOW LIT UP ALONG THE NRN TIER BUT IT IS WORKING
INTO VERY DRY AIR - NEAR 50F DEWPOINTS IN THE CENTRAL MTS. THE
SHOWERS MAY MAKE A RUMBLE OR TWO OF THUNDER...BUT THEY ARE
VERTICALLY CHALLENGED WITHOUT MOISTURE TO FUEL THEM AND MAKE THEM
GROW TALL ENOUGH TO GLACIATE AND PRODUCE LIGHTNING. WINDS COULD
GUST INTO THE 30S...BUT NOT LIKELY ANY WORSE. BETTER DEWPOINTS
POOLING UP OVER NERN OH ATTM...AND SH/TSRA THERE CURRENTLY COULD
SLIDE INTO WRN PA LATER THIS EVENING. HEAT AND MUCH BETTER
DEWPOINTS ALONG THE OLDER FRONT OVER THE SRN TIER ALSO FIRING A
FEW SHRA. AGAIN...ISOLD T POSSIBLE...BUT NO WORRY FOR SEVERE
WEATHER. THE SHOWERS SHOULD DWINDLE AS THE NIGHT STARTS AND
STABILIZATION OCCURS. HOWEVER...ANOTHER FRONT - THIS ONE WITH REAL
DRY AIR BEHIND IT - LURKS JUST S OF LAKE ONTARIO AT THIS TIME. IT
WILL ALSO ONLY MOVE SLOWLY TO THE SOUTH.

&&

.SHORT TERM /11 PM THIS EVENING THROUGH 6 PM TUESDAY/...
ANY BREAK IN RADAR ECHOES ON THE KCCX SCOPE WILL PROBABLY BE ONLY
A FEW HOURS...AS MORE FORCING SLIDES ACROSS THE LOWER GREAT LAKES
TONIGHT. THIS WILL MEET UP WITH THE THIRD FRONT TO PRODUCE SCT
SHRA LATER TONIGHT IN THE N/W. WILL LEAVE POPS IN THE CHC RANGE
FOR NOW DUE TO MODEL DIFFERENCES IN PLACEMENT OF ANY CONVECTIVE
DEVELOPMENT. 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
NOTICABLY 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 /22Z MONDAY THROUGH SATURDAY/...
RADAR SHOWING A FEW ISOLATED SHRA AT 22Z ACROSS CENTRAL PA...WHICH
SHOULD DISSIPATE AS BLYR COOLS ARND SUNSET. BASED ON LATEST
TRENDS...CAN/T RULE OUT A BRIEF VSBY REDUCTION EARLY THIS EVENING
AT IPT...MDT OR LNS. HOWEVER...ODDS DON/T FAVOR IT.

A COLD FRONT WORKING SE FROM THE GRT LKS COULD PRODUCE A LATE
NIGHT SHRA 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 LATE 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 LATE
TONIGHT. HOWEVER...IFR IS A 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 DURING TUES AFTN...AS COLD FRONT WORKS SOUTH
ACROSS THE STATE. ALTHOUGH VFR CONDS WILL PREDOMINATE...A BRIEF
VSBY REDUCTION IS POSSIBLE WITH THE SHRA/TSRA.

OUTLOOK...
WED-FRI...NO SIG WX EXPECTED.
SAT...SCT TSRA POSS.

&&

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

&&

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