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000
FXUS61 KPBZ 132343 AAB
AFDPBZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PITTSBURGH PA
743 PM EDT MON MAY 13 2013

.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN THROUGH TUESDAY. A WARM FRONT WILL
CROSS THE REGION TUESDAY NIGHT...FOLLOWED BY A COLD FRONT
WEDNESDAY. THIS FRONT WILL BECOME STATIONARY ACROSS THE OHIO
VALLEY INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TUESDAY/...
STLT SHOWS A SHRTWV EXITING THE RGN...WITH SFC HIGH PRES BLDG IN.
THIS WL QUICKLY END ANY SHWRS AND CLR OUT THE CLOUDS. AS
DECOUPLING TAKES PLACE AND WINDS DROP...EXP TEMPS TO DROP AT OR
BELOW FREEZING ACRS AREAS NR THE OH/WV BORDER EWD EVEN WITH SOME
CI MOVG IN. THE CI WL INCR OVRNGT...WHICH SHOULD HELP KEEP TEMPS
ABV FREEZING IN WRN AREAS WITH SOME VRY WK WRM AIR ADVCTN ALOFT.
KEPT THE FROST ADVY AND FREEZE WRNG AS IS. TUE HIGH PRES SHIFTS
EWD WITH SRLY FLOW. INCRG AC AND WRM AIR ADVCTN COULD BRING A SLGT
CHC OF A SHWR TO THE RGN AS WELL.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
WMFNT WILL CROSS RGN TUE NGT...LEADING TO SGFNT INCR IN MSTR AND
TEMPS FOR WED. WIND XPCD TO VEER TO WSWLY BY WED AFTN...WHICH WILL
CONT TO ADVCT MSTR INTO RGN AND WILL AID IN MAXIMA REACHING LWR
80S ACRS MUCH OF RGN. SLOWLY-ADVCG CDFNT WILL APRCH FCST AREA WED
AFTN.

MODEST HEIGHT FALLS WILL ACT ON COMPARABLY MODEST INSTBY ALONG
THIS CDFNT AND WILL GENERATE SHWRS AND TSTMS WED AFTN-EVE. POPS
WERE INCRD SGFNTLY FROM PREV FCST. SVR WX POTL WILL BE LMTD BY DEG
OF MSTR...WHICH LKLY WILL BE LWR THAN WHAT APPEARS IN THE MODELS.
IF RICH MSTR DOES MATERIALIZE AS FCSTD IN MODELS...INSTBY WILL BE
GREATER...AND SVR WX WILL BE PSBL.   UPDATE...KRAMAR

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
PRIMARY CHG IN EXTENDED WAS TO INCR POPS ON MON. MSTR-RICH WARM
SECTOR WILL BE FOUND ACRS MUCH OF THE RGN IN ADVC OF A POTENT H5
TROF EJECTING FROM THE SRN PLNS INTO THE OHVLY. FAVORABLY-TIMED
WAVE...STG H5 FLOW AND MDT INSTBY WILL CONTRIBUTE TO TSTM DVLPMT
MON AFTN-MON NGT. PREV DISCUSSION FOLLOWS.  UPDATE...KRAMAR

THE MODELS AGREE IN A LOW AMPLITUDE RIDGE REMAINING OVER THE
CENTRAL CONUS THROUGH AT LEAST SUNDAY BEFORE A DEEPENING TROUGH
AMPLIFIES THE RIDGE AND MOVES IT EASTWARD FOR THE BEGINNING OF NEXT
WEEK. HOWEVER...THERE ARE INHERENT DIFFERENCES IN THE TIMING AND
STRENGTH OF A SERIES OF SHORTWAVES AS THEY MOVE THROUGH THE
FLOW...DECREASING CONFIDENCE THROUGH THE PERIOD. THUS...OPTED TO
KEEP NO HIGHER THAN CHANCE POPS THROUGH MUCH OF THE PERIOD...WHICH
IS RIGHT IN LINE WITH BOTH HPC/MEX GUIDANCE. BOTH THE ECMWF AND GFS
GRADUALLY WARM TEMPERATURES THROUGH THE PERIOD KEEPING TEMPERATURES
5-10 DEGREES ABOVE SEASONAL AVERAGES THROUGH THE PERIOD.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
EXP VFR CONDS AND DCRG WNDS TNGT AS HIGH PRES BLDS IN. VFR SHOULD
CONT INTO TUE ALTHOUGH MID AND HIGH CLDS WL BE INCRG. WNDS EXPD TO
PICK UP OUT OF THE S TUE AT 5-10KT.

.OUTLOOK.../TUESDAY NIGHT THROUGH SATURDAY/...
SCT SHWRS/TSTMS WL BRING PSBL RESTRNS WED INTO THU. VFR EXP FRI
WITH INCRG SHWR/TSTM CHCS FOR SAT.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...FROST ADVISORY FROM 1 AM TO 8 AM EDT TUESDAY FOR OHZ039-040-
     048>050-057>059-068-069.
     FREEZE WARNING FROM 1 AM TO 8 AM EDT TUESDAY FOR OHZ041.
PA...FREEZE WARNING FROM 1 AM TO 8 AM EDT TUESDAY FOR PAZ007>009-
     013>016-020>023-029-031-073>076.
WV...FREEZE WARNING FROM 1 AM TO 8 AM EDT TUESDAY FOR WVZ001>004-
     012-021>023.

&&

$$