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000
FXUS61 KCTP 210036
AFDCTP

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

.SYNOPSIS...

A WARM HUMID AIRMASS WILL REMAIN IN PLACE THROUGH MID WEEK.
EXPECT WELL ABOVE NORMAL AFTERNOON TEMPERATURES THROUGH WEDNESDAY
BEFORE A COLD FRONT BRINGS TEMPERATURES BACK BELOW NORMAL WITH
DRIER CONDITIONS FOR THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...

DIURNAL CONVECTION THAT FIRED OVER THE HIGHLANDS OF THE SOUTHWEST
HAS ALL BUT VANISHED WITH LOWERING SUN ANGLES. THE REGION IS UNDER
A WARM AND HUMID AIRMASS SO IT WILL BE A MUGGY OVERNIGHT WITH SOME
PATCHY FOG AFTER MIDNIGHT.

AREAS OF LOW CLOUDS AND PATCHY FOG ARE POSSIBLE LATE TONIGHT SINCE
WILL DEWPOINTS REMAIN HIGH AND WINDS WILL FALL OFF TO LIGHT AND
VARIABLE. CONVECTION OVER LAKE HURON AND SOUTHERN MICHIGAN CRESTING
THE UPPER RIDGE TO OUR WEST COULD SNEAK INTO THE NW AFTER
MIDNIGHT...BUT AT THIS TIME SHORT RANGE HIGH RES MODELS ARE
FORECASTING IT TO DIMINISH RAPIDLY BEFORE IT BECOMES A PROBLEM. WILL
HAVE TO BE WATCHED BUT FOR NOW I JUST HAVE SMALL CHANCES FOR
THUNDERSTORMS OVER NWRN AREAS LATER TONIGHT. MINS WILL AGAIN BE
MUGGY UPPER 50S AND LOWER 60S.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...

TUESDAY...WE WILL BE 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 MONDAY/...
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.

&&

.AVIATION /23Z MONDAY THROUGH SATURDAY/...
LATE AFTN RADAR LOOP SHOWING A FEW SHRA/TSRA HAVE DEVELOPED OVR
THE LAUREL HIGHLANDS. A BRIEF VSBY REDUCTION IS POSSIBLE AT
AOO/JST/UNV THRU ARND 00Z. ANY REMAINING SHRA/TSRA SHOULD
DISSIPATE AFTER SUNSET...AS BLYR COOLS/STABILIZES.

HIGH DEWPOINTS AND LIGHT WINDS WILL LEAD TO AREAS OF FOG AFTER
06Z TUESDAY. BULK OF MDL GUIDANCE TARGETS THE EASTERN HALF OF THE
STATE FOR THE LOWEST /LIKELY BLW 1SM/ VSBYS...DUE TO A NEARLY CALM
WIND.

AM FOG SHOULD BURN OFF BTWN 13-16Z TUESDAY. HOWEVER...PM TSRA WILL
AGAIN BE AN AVIATION CONCERN. THE BEST CHC OF A TSRA AND
ACCOMPANYING BRIEF VSBY REDUCTION WILL BE DURING THE PM HOURS
ACROSS THE N MTNS AND SOUTHWARD ALONG THE LAUREL HIGHLANDS.

.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...LA CORTE/LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...LA CORTE/CERU
AVIATION...FITZGERALD/LAMBERT