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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCTP 200923
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
523 AM EDT MON MAY 20 2013

.SYNOPSIS...
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A WARM FRONT WILL ATTEMPT TO MOVE THROUGH THE AREA TODAY. IT SHOULD
SUCCEED IN DOING SO...BRINGING INCREASING WARMTH AND HUMIDITY TO
THE REGION THROUGH MID-WEEK. EXPECT WELL ABOVE NORMAL AFTERNOON
TEMPERATURES 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.
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&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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MOISTURE STILL TRAPPED UNDER THE STEEP INVERSION AND STRATUS IS
EVEN TRYING TO RE-ESTABLISH OVER WRN PA AT 09Z. THE STRATUS WILL
BE STUBBORN TO BREAK UP AND SOME EASTERN AREAS MAY NOT GET RID OF
THE CLOUDS BY THE END OF THE DAY. THE FRONT IS STILL VERY
DIFFICULT TO MAKE OUT DUE TO RATHER SIMILAR DEWPOINTS AND RATHER
GENTLE GRADIENT TO THE SFC PRESSURE. THE RIDGE AXIS IS WELL OFF
SHORE NOW BUT THE LACK OF GOOD SRLY WIND IS A TICK MARK ON THE
NEGATIVE SIDE FOR THE FRONT TO MAKE IT THROUGH THE AREA TODAY. ON
THE PLUS SIDE IF THE LEDGER SHEET - THE STRONG MAY SUNSHINE - WE
ARE NOW ONLY 1 MONTH FROM SOLSTICE - SHOULD WORK ON THE EDGES OF
THE STRATUS AND PERCOLATE SOME DIURNAL CU. ALL MDL SOUNDINGS BREAK
THE INVERSION AND CREATE ISOLD/SCT SHRA IN THE SRN TIER AND
ANOTHER AREA OVER THE NWRN MTS. WILL KEEP POPS LOWEST IN THE NE
AND CENTRAL MTS.
-- End Changed Discussion --

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
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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.
-- End Changed Discussion --

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
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THE MEDIUM RANGE GUIDANCE CONTINUES TO ADVERTISE A RATHER UNSETTLED
PERIOD FOR MUCH OF THE UPCOMING WEEK.

WE ARE AND WILL REMAIN BASICALLY UNDER A MEAN UPPER RIDGE...AND
THE STORM APPROACHING FROM THE WEST WILL TAKE IT/S TIME MOVING
THROUGH. SEVERE OUTLOOK FOR DAY3/WED DOES MENTION NWRN PA...CLOSE
TO THE SFC LOW AND THE BETTER UPPER FLOW. 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...AND IS MUCH CLOSER TO WHAT THE GFS HAS BEEN SAYING ABOUT
THE AIRMASS. THE ZERO C LINE AT 8H SEEMS TO STAY NORTH OF THE
STATE NOW...WITH MODIFICATION TAKING PLACE AS IT IS ALMOST SUMMER
IN CANADA...TOO.
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&&

.AVIATION /09Z MONDAY THROUGH FRIDAY/...
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A MOIST SERLY FLOW OFF OF THE ATLANTIC OCEAN WILL CONTINUE TO
PRODUCE WIDESPREAD STRATUS AND LIFR/IFR CIGS ACROSS CENTRAL PA
OVERNIGHT WITH CIGS BLO 1000 FT AT MOST AIRFIELDS. A BIT OF
DRIZZLE AND AREAS OF FOG WILL ALSO ADD TO LOWER VSBYS AT MANY SITES.
NEAR TERM MDL DATA INDICATING A NEARLY SATURATED SFC- 900MB LYR
ACROSS THE AREA TONIGHT.

SIGNIFICANT IMPROVEMENT IN FLYING CONDS IS EXPECTED LATER THIS
MORNING/AFTER SUNRISE...AS A WARM FRONT LIFTS THRU THE AREA AND
SFC FLOW SHIFTS TO THE SSW. MDL SOUNDINGS AND SREF DATA INDICATE
PREDOMINATELY VFR CONDS ARE LIKELY EVERYWHERE BY THE AFTN.
HOWEVER...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...NO SIG WX EXPECTED.
-- End Changed Discussion --

&&

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

&&

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