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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KPBZ 151455
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1055 AM EDT WED MAY 15 2013

.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA THIS AFTERNOON...BRINGING THE
RISK FOR SHOWERS AND STORMS. DRY WEATHER WILL RETURN FOR MOST OF
THE AREA ON THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
HIGHER WINDS STARTING TO MIX DOWN TO SURFACE IN A TIGHT PRESSURE
GRADIENT UNDER LOW PRESSURE NEAR LAKE HURON. COLD FRONT INTO NORTHWEST
OHIO AT 15Z. THE MAIN CONCERN WILL BE HOW MUCH SURFACE HEATING CAN
BE REALIZED AHEAD OF FRONT. MESOSCALE MODELS SEEM TO BE WELL
OVERDONE WITH AVAILABLE LOW LEVEL MOISTURE AND SURFACE BASED CAPE.
WITH MORNING SOUNDINGS AT KILN AND KPBZ SHOWING STRONG CAP IN
PLACE...EXPECT FRONT WILL HAVE BEST CHANCE OF FIRING STRONG
THUNDERSTORMS FROM I-70 SOUTHWARD LATE THIS AFTERNOON AND EVENING
WHEN FORECAST SOUNDING SHOW CAP BREAKING. NO CHANGES TO POPS AS THERE
WILL BE FAIRLY GOOD COVERAGE OF SHOWERS WITH THE FRONT.

FORECAST TEMPERATURES THIS AFTERNOON STILL APPEAR IN LINE ALTHOUGH
FRONT MAY BE MOVING SOUTHEAST A BIT FASTER THAN PREVIOUSLY PROGGED
AND COULD CUT OFF WARM ADVECTION SOMEWHAT EXCEPT IN THE AWAY FROM
THE FAR SOUTH AND WEST.

FRONT WILL SLOWLY PUSH SOUTH INTO WEST VIRGINIA TONIGHT AS AN
UPPER LEVEL TROUGH STRENGTHENS ACROSS NEW ENGLAND. SCATTERED
SHOWERS ARE THUS POSSIBLE...MAINLY FROM I-70 SOUTHWARD...ALBEIT
WITH DIMINISHING CHANCES THROUGH THE PERIOD.
-- End Changed Discussion --

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY/...
-- Changed Discussion --
A GOOD PUSH OF COOLER AND DRIER AIR IS INDICATED IN THE WAKE OF
THE FRONT AND HAVE ADJUSTED TEMPERATURES AND DEW POINTS DOWN
CLOSER TO NEW GFS MOS FOR THURSDAY. SCATTERED SHOWERS ARE STILL POSSIBLE...AGAIN
FROM I-70 SOUTHWARD...WITH DIMINISHING CHANCES FRIDAY.
-- End Changed Discussion --

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A SERIES OF SHORTWAVES EMBEDDED IN LOW AMPLITUDE RIDGE OVER THE
EASTERN CONUS WILL MOVE TOWARDS THE OHIO VALLEY THROUGH THE WEEKEND
FOLLOWED BY AN APPROACHING TROUGH BY THE END OF THE PERIOD. MODELS
ARE IN AGREEMENT WITH OVERALL PATTERN BUT DIFFER IN LOCATION AND SET
UP OF BOUNDARY ON THE WEEKEND. KEPT IN NO HIGHER THAN CHANCE POP FOR
THE MAJORITY OF THE PERIOD KEEPING IT IN LINE WITH MEX GUIDANCE.
TEMPERATURES WILL GRADUALLY RISE THROUGH NEXT WEEK.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
A WRM FNT WL CONT TO LIFT NWD TNGT...WITH GENL VFR CONDS EXPD
INTO WED. LLVL JET PUSHES INTO OH OVRNGT...SO ADDED LLWS TO THE
ZZV TAF. OTRW EXP SW WNDS TO GUST ARND 25KT WED. A CDFNT WL DROP S
WED AS WELL...WITH SOME SHWRS/TSTMS EXPD TO DVLP ESP IN THE
AFTN...MAINLY S OF I 80. ADDED AFTN VCTS TO ALL SITES EXCEPT FKL
AND DUJ...WHERE LESS INSTAB IS EXPD. AFT FROPA EXP A WSHFT TO THE
W.

.OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
THE CDFNT SHOULD PUSH S OF THE RGN WED NGT WITH GENL VFR CONDS
EXPD THRU FRI. SHWR/TSTM CHCS WL INCR AGAIN FRI NGT THRU SUN AS A
WRMFNT LIFTS SLOWLY N ACRS THE RGN.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$