Area Forecast Discussion
Issued by NWS State College, PA

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000
FXUS61 KCTP 280045
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
845 PM EDT MON JUL 27 2015

.SYNOPSIS...
A FRONT ALONG THE MASON DIXON LINE WILL DISSIPATE AS IT SLOWLY
SAGS FURTHER TO THE SOUTH. HIGH PRESSURE WILL BUILD INTO THE
REGION THROUGH MIDWEEK AS THE TEMPERATURE AND HUMIDITY INCREASE.
THE NEXT FRONT WILL BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS
WEDNESDAY NIGHT AND THURSDAY...BEFORE SEASONABLY WARM CONDITIONS
RETURN.

&&

.NEAR TERM /UNTIL MIDNIGHT TONIGHT/...
TWO AREAS OF PERSISTENT ISOLATED CONVECTION...ONE OVER THE LAUREL
HIGHLANDS AND THE OTHER IN THE MID SUQ VALLEY...SHOULD GRADUALLY
WEAKEN WITH LOSS OF HEATING OVER NEXT COUPLE OF HOURS. THOUGH A
FEW NEW CELLS WILL PROB REGENERATE IN THESE AREAS VIA GUST FRONT
INTERACTIONS. AN ISOLATED CELL STILL POSS THROUGH MID EVE IN THE
LOWER SUSQ...BUT LOOKING MORE AND MORE UNLIKELY. QUITE MILD TEMPS
WILL JUST SLOWLY FALL ACROSS CENTRAL/SOUTH THROUGH LATE
EVE...WHILE LOWER DEWPOINTS ACROSS NORTHERN MTNS WILL ALLOW TEMPS
TO FALL FASTER THERE.

&&

.SHORT TERM /MIDNIGHT THROUGH 6 PM TUESDAY/...
HIGH PRESSURE TAKES OVER THROUGH THE LATE EVENING AND CAUSES SKIES
TO CLEAR OUT. THE SUMMERY DEWPOINTS...CLEAR SKIES AND STILL AIR
WILL ALLOW FOG TO FORM IN AT LEAST THE VALLEYS OF THE N/C COS BUT
ALSO ACROSS THE SOUTH - ESP WHERE ANY RAIN HAD FALLEN EARLIER.
MINS WILL DIP INTO THE 50S IN THE NRN VALLEYS...AND SHOULD HIT THE
CROSSOVER TEMPS IN ALMOST ALL LOCATIONS AS EVEN THE SRN TIER
SHOULD FALL INTO THE 60S.

TUESDAY LOOKS VERY NICE IF YOU LIKE THE HOT AND HUMID STUFF. MAXES
WILL RUN AT 90F IN THE SOUTH WITH 575 THICKNESSES AND 8H TEMPS OF
18-20C. M80S ELSEWHERE. ONLY THE LAURELS MAY STAY IN THE L80S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
RIDGE OVER CENTRAL U.S. WILL EXPAND INTO THE GREAT LAKES AND MID
ATLANTIC REGION THROUGH MIDWEEK. THEN RIDGING WILL BE REPLACED BY
BROAD TROUGH OVER EASTERN U.S. AS MAIN LARGE BUBBLE OF HIGH
PRESSURE RETROGRADES WESTWARD TO THE FOUR CORNERS REGION LATER IN
THE WEEK.

DRY PERIOD LASTS INTO WEDNESDAY WITH HIGH PRESSURE IN CONTROL AT
THE SFC AND ALOFT. NEXT CHC FOR RAIN/TSTMS WILL ARRIVE WED NIGHT
INTO THURSDAY AS NEXT TROUGH AND ITS ASSOCD COLD FRONT REACHES THE
APPALACHIANS.

BEHIND THAT SYSTEM...MAINLY DRY WEATHER RETURNS FOR FRI AND SAT.
ANOTHER WAVE SLIDES IN FROM THE WEST SUN INTO MON RE-ESTABLISHING
THE TROUGH. ECMWF/GFS STILL LOOK TO BE LATCHING ONTO AT LEAST A
WEAK WAVE ORIGINATING OVER THE SOUTHEAST U.S. AND LIFTING IT
NORTHWARD ALONG THE APPALACHIANS BY MON...WHICH COULD HAVE IMPACTS
ON THAT FORECAST PERIOD. BUT FOR NOW WILL BROADBRUSH IN GENERALLY
UNSETTLED WEATHER FOR LATE NEXT WEEKEND INTO START OF NEXT WEEK.

TEMPS WILL BE GENERALLY ABOVE NORMAL FOR MUCH OF THE WEEK...WITH
A PEAK IN THE HEAT OCCURRING AROUND WED IN THE NORTH AND WED-THU
ACROSS THE SOUTH...WITH HIGHS PEAKING FROM THE MID 80S TO
LOWER/MID 90S. DEWPOINTS WILL ALSO INCREASE MIDWEEK...AS HEAT
INDEX VALUES MAY APPROACH 100F IN THE LWR SUSQ VLY. COOLER AND
LESS HUMID WEATHER RETURNS AS WE HEAD INTO NEXT WEEKEND.

&&

.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
SURFACE HIGH PRESSURE RIDGE EXTENDED FROM MICHIGAN...ESE ALONG THE
PENN/NEW YORK BORDER. LIGHT AND VARIABLE OR VERY LIGHT EAST TO NE
WIND WILL OCCUR OVERNIGHT.

CLEAR SKIES AND STILL RELATIVELY HIGH SFC DEWPOINTS...RANGING
FROM THE MID 60S TO AROUND 70F ACROSS THE SOUTHERN HALF OF
PENN...TO THE UPPER 50S ACROSS THE NORTHERN TIER COUNTIES OF PENN
WILL HELP TO PROMOTE AREA OF FOG LATE TONIGHT THROUGH THE MID
MORNING HOURS OF MONDAY. THE FOG WILL BECOME LOCALLY DENSE BETWEEN
07Z-11Z TUESDAY.

MANY LOCATIONS COULD GO IFR OR EVEN LIFR AS TEMPS SHOULD EASILY
DROP BELOW CROSSOVER TEMPS. AFTER ANY FOG/STRATUS BRNS AWAY
TUES...THERE SHOULD NOT BE MUCH IN THE WAY OF CLOUDS AS UPSTREAM
RIDGING GETS NEARER.

OUTLOOK...

WED...MAINLY VFR.
THU...CFROPA W/VERY BRIEF REDUCTIONS DUE TO TSRA.
FRI...MAINLY VFR.
SAT...MAINLY VFR AM...SHRA/TSRA POSS NW.

&&

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

&&

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


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