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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCTP 181841
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
241 PM EDT SAT MAY 18 2013

.SYNOPSIS...

-- Changed Discussion --
A WAVY FRONTAL BOUNDARY EXTENDING FROM THE UPPER MIDWEST THROUGH
THE OHIO VALLEY AND ACROSS THE CENTRAL APPALACHIANS INTO SOUTHERN
MID-ATLANTIC STATES WILL SLOWLY RETURN NORTHWARD AS A WARM FRONT
LATE SUNDAY INTO MONDAY. THE WARM FRONT WILL THEN STALL OUT ACROSS
UPSTATE NEW YORK AND NEW ENGLAND BEFORE SINKING BACK TO THE SOUTH
AND OSCILLATING OVER PENNSYLVANIA INTO THE MIDDLE OF NEXT WEEK.
THE FRONT SHOULD FINALLY PUSH SOUTH OF THE AREA BY LATE NEXT WEEK
OR EARLY IN THE WEEKEND...AS A LARGE CANADIAN HIGH PRESSURE SYSTEM
DROPS SOUTHEAST INTO THE GREAT LAKES REGION. OVERALL EXPECT A
PROLONGED STRETCH OF UNSETTLED WEATHER OVER THE NEXT SEVERAL DAYS.
TEMPERATURES WILL BE MORE TYPICAL OF EARLY SUMMER BY TUESDAY...
BEFORE COOLING BELOW NORMAL BY NEXT WEEKEND.
-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 11 PM THIS EVENING/...

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DID CUT BACK SOME ON POPS ACROSS THE SW ON THE 130 PM
UPDATE...BUT NOW STORMS ARE JUST TO THE WEST OF THE CWA...
THUS ADJUSTED SOME MORE.

MOST OF THE AREA IS RATHER CLOUDY...NOT REAL HIGH DEWPOINTS...
THUS ONLY HAVE THUNDER IN FAR SW AREAS.

NO MAJOR CHANGES AT THIS POINT.
-- End Changed Discussion --

&&

.SHORT TERM /11 PM THIS EVENING THROUGH 6 PM SUNDAY/...

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SEEMS LIKE A NO-BRAINER TO FCST THICK LOWER CLOUDS TONIGHT OVER
MUCH OF THE AREA...AND THE UPSLOPE FLOW WILL CREATE PATCHY LIGHT
RAIN OR DRIZZLE OVER MUCH OF THE AREA THROUGH THE NIGHT.

ABOUT THE TIME OF YEAR TO SEE HIGHER DEWPOINTS. OFTEN CAN SEE
HIGHER QPF AMTS ACROSS THE FAR SE AREAS...ESPECIALLY LANCASTER
COUNTY...MAINLY LATE AT NIGHT...BUT IN THIS CASE...DID NOT GO
TOO HIGH...GIVEN THAT I NORMALLY LIKE TO SEE FCST DEWPOINTS
HIGHER.

DID NOT CHANGE TEMPS MUCH...JUST A TAD HIGHER ACROSS THE WEST.
-- End Changed Discussion --

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...

THE LAST TWO CYCLES OF GLOBAL GUIDANCE CONTINUES TO DEPICT A
HIGHLY AMPLIFIED 500MB PATTERN HOLDING FIRM THROUGH THE MEDIUM
RANGE PERIOD. A COMPRESSED WAVELENGTH BETWEEN PAC NW CLOSED
LOW/HIGH PLAINS RIDGE/UPPER MS VLY CLOSED LOW/TROUGH AND SERN U.S.
RIDGE WILL EVENTUALLY WIDEN AND EVOLVE TO A WRN TROUGH/PLAINS
RIDGE/ERN TROUGH CONFIGURATION /ESSENTIALLY A CONUS OMEGA BLOCK/
BY THE END OF THE PERIOD. IN GENERAL...THE OPRN MDLS AND ENS MEANS
SHOW REASONABLY GOOD AGREEMENT ON THE LARGE SCALE SYNOPTIC FEATURES
WITH THE USUAL TIMING/PLACEMENT DIFFS RELATED TO SFC FRONTS AND
QPF - WHICH IS TO BE EXPECTED AT THIS RANGE.

IN TERMS OF SENSIBLE WEATHER HIGHLIGHTS...THE OVERALL PATTERN WILL
BE A RATHER UNSETTLED AND POTENTIALLY VERY WET ONE WITH DAILY
OPPORTUNITIES FOR CONVECTIVE PCPN. WITH PRECIPITABLE WATER VALUES
ABOVE NORMAL THROUGH THE ENTIRE PERIOD...WENT ABOVE CLIMO POPS
USING AN EVEN BLEND OF GFS/EC BASED MOS DATA. TEMPERATURES IN THE
FIRST HALF OF THE PERIOD /DAYS 4-5 OR TUE-WED/ SHOULD AVG SEVERAL
DEGREES ABOVE LATE-MAY CLIMATE NORMALS. THIS WARM SPELL SHOULD BE
FOLLOWED BY A GRADUAL DOWNWARD TREND IN MAX/MIN FOR DAYS 6 AND 7
THR-FRI (AND LKLY INTO DAY 8/SAT) WITH A COLD FRONT EXPECTED TO
MOVE THROUGH THE REGION SOMETIME LATE NEXT WEEK.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...

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5-18/18Z...

VFR FLYING WILL CONTINUE THIS AFTERNOON ACROSS MOST OF
THE AREA... WITH BKN-OVC ALTO CU BASES AROUND 7-10KFT AGL.

HOWEVER...JUST STARTING TO SEE LOWER CLDS WORKING NORTHWARD FROM
MD AND VA...INTO BEDFORD COUNTY...AND NOW JUST INTO AOO. STRONG
SUN ANGLE... SIMILAR TO MID JULY...MAY TRY TO SLOW DOWN NORTHWARD
EDGE OF THIS AREA OF CLDS...BUT EXPECT THE THE LOW-LEVEL FLOW TO
CONTINUE VEER TO THE SE THIS AFTN AND DIRECT INCREASINGLY
MOIST/MARITIME AIR INTO THE REGION. THIS WILL RESULT IN LOWERING
CIGS THIS EVE WITH WIDESPREAD MVFR TO IFR CONDS XPCTD TONIGHT
INTO AT LEAST EARLY MONDAY. CONFIDENCE IS ABOVE AVG.

A STATIONARY FRONTAL BOUNDARY WILL LIFT SLOWLY NORTHWARD ACROSS
THE AIRSPACE BY TUESDAY...WHICH SHOULD ALLOW FOR SOME MARGINAL
IMPROVEMENT IN LCL FLYING CONDS. A RATHER UNSETTLED AND POTENTIALLY
WET PATTERN IS EXPECTED DURING THE MIDDLE TO SECOND HALF OF NEXT
WEEK...WITH DAILY CHC/S FOR CONVECTIVE PCPN AND ASSOCD RESTRICTIONS.

.OUTLOOK...

MON...MVFR-IFR CIGS.
TUE-THU...VFR-MVFR WITH SCT PM THUNDERSTORM IMPACTS.
-- End Changed Discussion --

&&

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

&&

$$
SYNOPSIS...DANGELO/MARTIN/STEINBUGL
NEAR TERM...DANGELO/MARTIN
SHORT TERM...DANGELO/MARTIN
LONG TERM...STEINBUGL
AVIATION...MARTIN/STEINBUGL