-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KPBZ 230520
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
120 AM EDT THU MAY 23 2013

.SYNOPSIS...
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SHOWER AND THUNDERSTORM CHANCES WILL CONTINUE UNTIL A FRONT CROSSES
THE REGION THIS EVENING. MUCH COOLER WEATHER CAN BE EXPECTED FOR
THE WEEKEND.
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&&

.NEAR TERM /THROUGH TODAY/...

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SHORTWAVE MOVING THROUGH SWLY FLOW ON THE ERN FLANK OF MS VALLEY
UPR TROF CONTS TO SPREAD SHWRS...AND ISOLD TSTM OVR THE UPR OH
VALLEY EARLY THIS MRNG. THAT DISTURBANCE WL MAINTAIN NELY PROGRESS
AND COVERAGE OF RAIN WL DIMINISH AS THE PREDAWN PROGRESSES.

CONVECTIVE THRESHOLDS WL BE CONSIDERABLY LOWER TDA AS THE UPR TROF
SLIDES EWD. WITH CONVECTIVE TEMPS PROGGED IN THE MID TO UPR
60S...AND WITH OVRALL ASCENT INCRSG...POPS WERE INCRSD TO LIKELY
NMBRS AND TSTM MENTION WAS MAINTAINED.

DESPITE A RELATIVELY STRONG WIND FIELD...SEVERE POTENTIAL IS LOW
GIVEN THE OVRALL INSTABILITY LIMITATIONS.

NR TERM TEMPS WERE FORECAST USING TWEAKED LAMP GUIDANCE.
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&&

.SHORT TERM /TONIGHT THROUGH SATURDAY/...
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THE CDFNT WL COMPLETE A SWEEP OF THE REGION TNGT...BUT CHC POPS
WERE MAINTAINED INTO FRIDAY GIVEN THE PRESENCE OF THE MID/UPR
TROF. BLDG HIGH PRES SHOULD SUPPRESS THOSE RESIDUAL CHCS BY FRIDAY AFTN.

ISSUE THEREAFTER IS OF TEMPS AS DVLPMNT OF A HIGH AMPLITUDE ERN
CONUS TROF SPPRTS STRNG COLD ADVCTN. SHOULD SFC WIND DIMINISH
SUFFICIENTLY...PTCHY FROST IS PSBL BY DAYBREAK SATURDAY.

SHORT TERM TEMPS WERE FORECAST USING A BLEND OF PERSISTENCE AND
SREF MEANS.
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&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
DRY WEA IS EXPD THRU THE PERIOD WITH HIGH PRESSURE IN CONTROL. A
WRMFNT MAY APRCH BY MID WEEK BUT TOO MUCH UNCERTAINTY TO INCLUDE
ANY PCPN MENTION ATTM. TEMPS WL START OUT BLO AVG OVR THE
WEEKEND...THEN MODERATE TO SEASONAL LVLS AS HIGH PRESSURE SHIFTS E
OF THE AREA AND FLOW TURNS SRLY.

&&

.AVIATION /05Z THURSDAY THROUGH MONDAY/...
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EXP SCT TO NMRS SHWRS THRU THE PREDAWN AS A SHRTWV MOVES ACRS THE
REGION. GIVEN THE ELEVATED NATURE OF THE CONVECTION... BUT GENL
VFR WEA IS EXP WITH ONLY BRIEF MVFR RESTRICTIONS DUE TO VSBY.

MORE SHWRS AND SOME TSTMS ARE ANTICIPATED THIS AFTN AS A CDFNT
SLIDES CLOSER TO THE UPR OH REGION. MVFR...AND ISOLD IFR VSBY
SHOULD BE EXPECTED WITH THE PCPN...AND MORE GENL MVFR CONDITIONS
ARE EXPECTED WITH ACTUAL PASSAGE OF THE FRONT THIS EVE.

.OUTLOOK.../THURSDAY NIGHT THROUGH MONDAY/...
RESTRNS ARE LIKELY IN SHWRS INTO FRIDAY...BUT BLDG HIGH PRES WL
QUICKLY RTN VFR TO AREA PORTS BY AFTN. GENL VFR WL THEN PERSIST
INTO EARLY NEXT WEEK.
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&&

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

&&

$$

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