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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCTP 201851
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
251 PM EDT MON MAY 20 2013

.SYNOPSIS...
A WARM FRONT WILL MOVE SLOWLY NORTHEAST ACROSS THE STATE THIS
AFTERNOON AND EVENING. INCREASING WARMTH AND HUMIDITY WILL
OVERSPREAD THE REGION THROUGH THE MID-WEEK IN THE WAKE OF THIS
FRONT. EXPECT WELL ABOVE NORMAL AFTERNOON TEMPERATURES ACROSS THE
WESTERN HALF OF THE STATE THIS AFTERNOON...AND IN ALL AREAS TUESDAY
AND WEDNESDAY. TEMPERATURES WILL COOL BACK BELOW NORMAL WITH DRIER
CONDITIONS BY THE WEEKEND AS A VERY COLD AIRMASS DROPS OUT OF
CENTRAL CANADA INTO THE GREAT LAKES AND NORTHEASTERN UNITED STATES.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MOISTURE AND THE ASSOCIATED EARLIER...EXTENSIVE DECK OF LOW
STRATUS/FOG WAS STILL TRAPPED UNDER THE STEEP INVERSION ACROSS THE
EASTERN HALF OF THE CWA. OVER APPROXIMATELY THE WRN HALF OF THE
STATE...THE CLOUD BASES HAVE BROKEN/LIFTED BY 1-2 KFT TO A
BKN...SHALLOW CU FIELD AS OF 16Z.

THE CLOUDS WILL BE SLOWLY MIXED OUT/DISSIPATED FROM WEST TO EAST
ACROSS THE SUSQ VALLEY DURING THE AFTERNOON HOURS. HOWEVER...A FEW
LOCATIONS EAST OF THE SUSQ VALLEY WILL STILL REMAIN CLOUDY FOR THE
REST OF THE DAY WITH TEMPS ONLY PEAKING IN THE MID 70S.

HIGH TEMPS ACROSS THE CENTRAL AND WEST WILL EASILY REACH THE UPPER
70S TO LOWER 80S FOR HIGHS UNDER A DECENT AMOUNT OF HAZY SUNSHINE.
A FEW SPOTS IN SCENT PENN /JUST EAST OF THE LAURELS/ COULD TOUCH 85F
WHERE THE MEAN...DOWNSLOPING SWRLY LLVL FLOW MAXIMIZING THE
ADIABATIC WARMING OF THE 14C AIR RESIDING AT THE 850 MB LEVEL.

ALTHOUGH ALL MDL SOUNDINGS BREAK THE INVERSION AND SUGGEST ISOLD/SCT
SHRA FORMING IN THE SRN TIER AND ANOTHER AREA OVER THE NWRN
MTS...BROADLY DIVERGENT LLVL FLOW WILL ACT TO NEGATE ANY ORGANIZED
AREAS OF CONVECTION THROUGH THE DAYLIGHT HOURS /FOR ALL AREAS EXCEPT
FOR PERHAPS WARREN CTY WHERE TSRA DEVELOPING ON THE WESTERN EDGE OF
A TIGHT 925-850 MB THETA-E BOUNDARY /JUST WEST OF KCLE/ COULD DRIFT
EAST AND AFFECT THE FAR NW ZONES AROUND DUSK.

WILL CONTINUE TO KEEP POPS LOWEST IN THE NE AND CENTRAL MTS...AOB 20
PERCENT.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MORE STRATUS AND FOG ARE POSSIBLE TONIGHT SINCE DEWPOINTS REMAIN
HIGH AND WINDS WILL STILL BE LIGHT. WILL COUNT ON THE LACK OF SUN
TO KILL THE SHOWERS/STORMS THIS EVENING...AND LEAVE POPS LESS THAN
20 PCT FOR THE BULK OF THE NIGHT. CONVECTION CRESTING THE UPPER
RIDGE TO OUR WEST COULD SNEAK INTO THE NW BY MORNING...BUT THIS IS
JUST WORTH A LOW CHC POP AT THIS POINT. MINS WILL AGAIN BE MUGGY
UPPER 50S AND LOWER 60S.

ON TUESDAY...WE SHOULD BE WELL INTO THE WARM SECTOR AHEAD OF THE
STORM CRAWLING IN FROM THE NORTHERN PLAINS/MIDWEST/UPPER LAKES.
THE WARM SECTOR AIR WILL BE QUITE WARM FOR THIS TIME OF
YEAR...HAVING SPENT PLENTY OF TIME COOKING OVER THE MS AND OH
VALLEYS WITH GOOD GULF INFLOW. TEMPS THERE RIGHT NOW ARE ABOUT 10F
ABOVE AVERAGES. THEREFORE...SUMMERTIME TEMPS OF UPPER 70S IN THE
HILLS TO MID 80S IN THE VALLEYS ARE EXPECTED ON TUESDAY. ALONG
WITH THE WARM TEMPERATURES...THE DEWPOINTS WILL BE SOLIDLY IN THE
60S. THIS WARM...MOIST AIR AND A WEAKENING RIDGE MOVING OVERHEAD
AND A LITTLE TO OUR EAST WILL CREATE A GOOD SITUATION FOR SCT AFTN
CONVECTION.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...

-- Changed Discussion --
THE LARGE UPPER LEVEL LOW BRINGING SEVERE WEATHER THROUGHOUT THE
MIDWEST WILL SLOWLY MAKE ITS WAY EASTWARD. THIS FLOW SHOULD BRING A
RATHER UNSETTLED PERIOD THROUGH THE WORK WEEK. AS THE UPPER LEVEL
RIDGE CONTINUES TO BREAK DOWN...STORMS WILL SLOWLY APPROACH.
 SEVERE OUTLOOK FOR DAY3/WED HAS THE WESTERN HALF OF THE CWA IN THE
SLIGHT RISK. SOUTHEASTERLY MOISTURE...COUPLED WITH INSTABILITY FROM
THE FRONT AND DAYTIME HIGHS IN THE 80S SHOULD ALLOW FOR A SUFFICIENT
ENVIRONMENT FOR DAYTIME STORMS/SHOWERS. SHEAR SHOULD BE
DECENT...ESPECIALLY AS MID RANGE MODELS ARE HINTING AT A LLJ THROUGH
WEDNESDAY AFTERNOON. THURSDAY WILL AGAIN FEATURE SCT/NMRS TSRA. THE
MED RANGE GUID IS NOW PRETTY SOLID WITH A THURS NIGHT/EARLY FRIDAY
PASSAGE OF THE COLD FRONT ASSOCD WITH THE SYNOPTIC SCALE STORM. MUCH
COOLER AIR AND DRIER CONDITIONS SHOULD FOLLOW FOR THE WEEKEND. ECMWF
HAS BACKED OFF ON THE COLD-NESS OF THE AIR MOVING DOWN WITH THE BIG
1030MB HIGH FOR THE WEEKEND...THOUGH IT LOOKS LIKE THE ZERO C LINE
AT 8H COULD CLIP THE NORTHWESTERN CORNER OF PA. MIN TEMPS FOR
SATURDAY MORNING WILL BE COOL BUT HAVE KEPT THEM IN THE LOW 40S TO
UPPER 30S. DRIER AIR ASSOCIATED WITH THIS FRONT SHOULD KEEP
PRECIPITATION OUT OF THE FORECAST THROUGH THE WEEKEND...WITH WEAK
HIGH PRESSURE BUILDING THROUGH SUNDAY. MEMORIAL DAY MAY SEEM SOME
CLOUDINESS AS THE RIDGE BREAKS DOWN TO DUE NORTHWESTERLY FLOW.
MOISTURE FROM A WEAK SHORTWAVE COULD BRING PRECIPITATION ALONG THE
MASON DIXON MONDAY EVENING...YET DUE TO IT BEING ON THE EDGE OF THE
FORECAST MUCH COULD CHANGE.
-- End Changed Discussion --


&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
A MOIST SERLY FLOW OFF OF THE ATLANTIC OCEAN /AND ON THE NE SIDE OF
A SLOW MOVING WARM FRONT/ WILL CONTINUE TO PRODUCE WIDESPREAD
STRATUS WITH MAINLY MVFR CIGS ACROSS THE EASTERN HALF OF PA THIS
AFTERNOON. GENERALLY BKN CIGS WITH BASES OF 3.4-4.5 KFT AGL WILL
OCCUR ACROSS THE REGION NEAR...AND TO THE WEST OF A KELM...TO KUNV
AND KMRB LINE FOR THE REST OF TODAY.

THERE IS A SLIGHT CHC OF AN AFTN TSRA ACROSS THE W MTNS...WHICH
COULD PRODUCE A BRIEF VIS/CIG REDUCTION.

.OUTLOOK...
TUE-THU...LOW CLOUDS/FOG POSS EARLY. SCT PM THUNDERSTORM IMPACTS
POSSIBLE.
FRI AND SAT...NO SIG WX EXPECTED.

&&

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

&&

$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...LA CORTE/CERU
AVIATION...LAMBERT/GARTNER