Area Forecast Discussion
Issued by NWS State College, PA

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FXUS61 KCTP 310202
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1002 PM EDT SUN AUG 30 2015

.SYNOPSIS...
A WEAK TROUGH DYING OVER THE REGION AND HIGH MOISTURE WILL RESULT
IN A FEW SHOWERS OVER MAINLY SOUTHERN PORTIONS OF CENTRAL
PENNSYLVANIA OVERNIGHT. SHOWERS WILL PERSIST ACROSS THE SOUTH
MONDAY MORNING...WHILE NORTHERN AREAS ARE MAINLY DRY. HOWEVER...
A PASSING AFTERNOON SHOWER OR THUNDERSTORM WILL BE POSSIBLE JUST
ABOUT ANYWHERE. HIGH PRESSURE OFF THE EAST COAST WILL LEAD TO
TEMPERATURES WELL ABOVE NORMALS ALL WEEK...WITH HIGH HUMIDITY...
AND AT LEAST A SLIGHT CHANCE OF AN AFTERNOON SHOWER OR
THUNDERSTORM EACH DAY. IT WILL FEEL MORE LIKE THE MIDDLE OF SUMMER
THAN SEPTEMBER.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
SHOWERS HAVE DWINDLED TO ISOLATED COVERAGE ACROSS THE SOUTH
CENTRAL MOUNTAINS AND MIDDLE SUSQUEHANNA RIVER VALLEY AT THIS
HOUR. WEAK DEFORMATION AND BOUNDARY LAYER MOISTURE CONVERGENCE IN
THIS REGION SUPPORT ISOLATED ACTIVITY THROUGH 06Z...ALTHOUGH MOST
AREAS FROM THE CENTRAL AND SOUTH CENTRAL MOUNTAINS EASTWARD WILL
REMAIN DRY.

FARTHER SOUTH...WEAK UPPER LOW OVER THE WESTERN CAROLINAS WILL
LIFT NORTHWARD OVERNIGHT ON THE WESTERN PERIPHERY OF THE SPRAWLING
WESTERN ATLANTIC UPPER HIGH CIRCULATION. THIS WILL MAINTAIN THE
FOCUS FOR POOLING MOISTURE AND FORCING FOR SHOWER ACTIVITY THROUGH
THE PRE DAWN HOURS ACROSS MY FAR SOUTH. MEANWHILE...AREAS TO THE
NORTH SHOULD BE DRY AFTER 06Z AS DEFORMATION LESSENS AND FORCING
FOCUS SHIFTS TO AREAS ALONG AND SOUTH OF MY SOUTHERN TIER.

PREVIOUS IDEA OF SHOWERS LINGERING LONGEST OVER THE SRN HALF OF
THE AREA GOOD AND ACTUALLY BUMPED POPS UP AS THE NIGHT WEARS ON
OVER MY SOUTHERN TIER COUNTIES. CLOUD COVER WILL BE GREATEST OVER
THE SOUTHERN THIRD TO HALF OF CENTRAL PA...WHILE THE NORTH SEES
PARTIAL CLEARING AND PEAKS OF THE NEARLY FULL MOON. SOME FOG MAY
DEVELOP...ESP IN PLACES WHICH HAD RAINFALL AND THOSE WHICH SEE
MORE CLEARING THAN OTHERS.  MINS WILL RUN IN THE 60S EVERYWHERE
AS DEWPOINTS SHOULD NOT GO ANY LOWER THAN 60F.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
SUBSIDENCE DOES NOT REALLY COME DOWN SOUTH ENOUGH TO ALLOW US TO
DRY OUT ON MON. THE UPPER HIGH WILL CONTINUE TO SLIDE EASTWARD BUT
SOME SEMBLANCE OF TROFFINESS REMAINS ACCORDING TO MOST GUID. WITH
THE SFC HIGH RETURN FLOW INCREASING...A FEW SHRA/TSRA ARE STILL
POSSIBLE MON...BUT MAINLY IN THE FAR SOUTH AND FAR NORTH. HAVE
ALLOW FOR LINGERING SHRA S IN THE MORNING AND EARLY AFTN...AND
MORE IN THE WAY OF DIURNAL SHRA IN THE NRN TIER. MAXES WILL BE A
FEW DEGS HIGHER THAN TODAY - IF WE CAN GET RID OF MOST OF THE
CLOUDS FOR A SHORT TIME - BECAUSE 8H TEMPS WILL BE ABOUT 2C
WARMER.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
ANOMALOUS UPPER LEVEL RIDGE WILL DOMINATE THE OHIO VALLEY AND
EASTERN UNITED STATES MUCH OF THE UPCOMING WEEK...WITH LATEST
GUIDANCE REMAINING FIRM FOR AN EXTENDED RUN OF 850HPA TEMPS
PEAKING DAILY AROUND 16-18C. THIS WILL TRANSLATE TO WELL ABOVE-
NORMAL SFC TEMPS. THIS WARMTH AND INCREASING HUMIDITY SHOULD ALLOW
FOR AT LEAST A SLIGHT CHC FOR DIURNAL CONVECTION EACH DAY...BUT
WARM MID-LEVELS WILL KEEP THE PROBABILITY OF WIDESPREAD RAINFALL
QUITE LOW.

BEST CHANCES FOR PRECIP WILL BE MIDWEEK /WED-THU-FRI/ WITH A
COUPLE SUBTLE FEATURES. FIRST...A WEAK UPPER LEVEL WAVE /BEST
PROGGED ON THE ECMWF/ SLIPS OVERHEAD ON WED AS BERMUDA HIGH
BRIEFLY RECEDES. AT SAME TIME A WEAK BACKDOOR COLD FRONT SLIPS
SOUTHWARD OFF THE EAST COAST. THIS COULD HELP POOL SOME LOW LEVEL
MOISTURE OVER THE MID ATLANTIC AND OHIO VALLEY AS MID LEVELS COOL
JUST A BIT...BRINGING POTENTIAL FOR SCT TSTMS. RIDGE BUILDS BACK
IN FOR FRI...BUT ANOTHER SURFACE BACKDOOR FRONT TRIES TO SLIP
ACROSS THE STATE AS SURFACE HIGH EXPANDS IN FROM THE NORTH. THIS
BOUNDARY SHOULD BRING SCT CONVECTION FOR FRI.

EXTENDED MODELS HINT AT POTENTIAL FOR DAILY CONVECTION CONTINUING
INTO THE WEEKEND ALONG SOUTHER BORDER...BUT OVERALL CONDITIONS
WILL BE MAINLY RAIN-FREE.

TEMPS PEAK MIDWEEK WITH READINGS APPROACHING 90F IN THE SE...AND
EVEN GETTING INTO THE 80S ELSEHERE...EASILY WELL ABOVE NORMAL FOR
THE FIRST WEEK OF SEPT. LOWS WILL ALSO REMAIN QUITE MILD MID/LATE
WEEK AS HIGH HUMIDITY AIR HANGS AROUND. SLIGHTLY COOLER BUT STILL
ABOVE AVERAGE TEMPS WILL CONTINUE THROUGH THE WEEKEND.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
A WEAK AREA OF LOW PRESSURE PASSING TO THE NORTH OF PA HAS SPAWNED
SCT SHRA/TSRA ACROSS CENTRAL PA EARLY THIS EVENING. LOSS OF
HEATING SHOULD CAUSE MOST OF THE SHOWERS TO DISSIPATE SHORTLY
AFTER SUNSET. HOWEVER...RADAR TRENDS AND LATEST HRRR IMPLIES A
BRIEF VIS REDUCTION CAN/T BE RULED OUT AT KMDT/KLNS SOMETIME BTWN
01Z-04Z.

FOCUS LATER TONIGHT WILL SHIFT TOWARD POTENTIAL OF FOG. LIGHT WIND
AND PTCLDY SKIES SHOULD PROMOTE LOCALLY DENSE VALLEY FOG AFTER
MIDNIGHT ACROSS NORTHERN PA. CLIMATOLOGY AND LATEST SREF/MOS
SUGGEST KBFD IS LIKELY TO EXPERIENCE IFR/LIFR VIS REDUCTIONS
LATE TONIGHT. ALSO...MAY HAVE TO CONTEND WITH DENSE FOG AT
KIPT...WHERE GROUND IS NOW WET FROM A PASSING SHOWER. COMPLICATING
FACTOR IS MID LVL CLOUDINESS OVERSPREADING THE SOUTHERN PART OF
THE STATE. FEEL CONFIDENT THESE MID LVL CLOUDS WILL BE THICK
ENOUGH TO DIMINISH THE RADIATIONAL COOLING AND ASSOC DENSE FOG
THREAT ACROSS SOUTHERN PA. HOWEVER...NOT AS CONFIDENT AT KIPT.

ANY AM VALLEY FOG ACROSS NORTHERN PA SHOULD BURN OFF BY LATE AM.
OTHERWISE...WIDESPREAD VFR CONDS AND LIGHT WIND APPEAR VERY
LIKELY MONDAY WITH ONLY ISOLD LATE DAY SHRA/TSRA POSSIBLE...AS
HIGH PRESSURE BUILDS OFF THE MID ATLANTIC COAST.

OUTLOOK...

TUE-FRI...PATCHY AM FOG POSS...MAINLY KBFD. ISOLD PM TSRA IMPACTS
POSSIBLE.

&&

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

&&

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



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