Area Forecast Discussion
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000
FXUS61 KPBZ 252231
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
631 PM EDT FRI JUL 25 2014

.SYNOPSIS...
SHOWER AND THUNDERSTORM CHANCES ARE RETURNING FOR THE WEEKEND.
COLDER WEATHER CAN BE EXPECTED NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
A WEAK SHORT WAVE APPROACHING FROM THE NORTHWEST WILL SLOWLY
INCREASE CLOUDS TOWARD MIDNIGHT...HOWEVER A LACK OF INSTABILITY
AND A VERY DRY COLUMN BELOW IT WILL LEAD TO VERY LOW CHANCES OF
RAINFALL THROUGH MOST OF THE NIGHT. BEFORE THE HIGHER CLOUDS
APPROACH...OPTIMAL RADIATIONAL COOLING CONDITIONS ARE LIKELY TO
EXIST WITH A VERY DRY BOUNDARY LAYER AND CALM WINDS. AS
SUCH...RAPID FALL OFFS IN TEMPERATURES ARE EXPECTED THIS
EVENING...BEFORE THE DIURNAL FALL OFF EBBS A BIT OVERNIGHT. MORE
ACTIVE WEATHER LOOKS TO HOLD OFF UNTIL AFTER TONIGHT. FRIES

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SHWR AND TSTM CHCS WL INCRS THIS WEEKEND AS A SERIES OF SHRTWVS
MOV OUT OF THE GREAT LAKES REGION. SFC FRONTAL PLACEMENT UNDR
INCRSG BUT MORE ZONAL FLOW WL BE CRITICAL FOR UPR OH VALLEY SVR
POTENTIAL. AT MOMENT...THE INITIAL SVR CHC...ALBEIT SLGT...RESIDES
WITH PASSAGE OF A POTENTIAL MCS OR REMNANTS LATE SATURDAY OR EARLY
SUNDAY.

BY SUNDAY...A TRAILING...AND MORE POTENT SHRTWV IS PROGGED OFF THE
GREAT LAKES. INCRSD DEEP LYR SHEAR AND STEEPENING MID LVL LAPSE
RATES WITH THAT FEATURE WL BE PLENTY SUFFICIENT FOR AN ARRAY OF
SEVERE WEATHER...BUT LIMITATIONS ARISE IN ACTUAL INSTABILITY
PARAMETERS AND BNDRY PLACEMENT...ESPECIALLY IN RELATION TO OUTFLOW
REINFORCEMENT FM THE SATURDAY SYSTEM.

AT ANY RATE...THE STORM PREDICTION CENTER HAS HIGHLIGHTED THE
REGION WITH THESE POSSIBILITIES AND LCL MENTION HAS BEEN CONTINUED
IN THE HAZARDOUS WEATHER OUTLOOK.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LONG TERM WL FEATURE AN ERN CONUS UPR TROF PERSISTING THRU
THE PD WITH BLO AVG TEMPS. SFC RIDGING WL BLD IN UNDER THE TROF BY
MID WK...KEEPING ONLY UNMENTIONABLE SLGT CHCS FOR SHWRS IN THE
FCST. THE RIDGING IS EXPD TO WKN BY LT WK WITH BETTER CHCS FOR
SHWRS/TSTMS.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
MOSTLY CLEAR SKIES WILL GIVE WAY TO SOME MID AND HIGH LEVEL CLOUDS
TONIGHT...ULTIMATELY KEEPING FOG DEVELOPMENT AT BAY. VFR
CONDITIONS WILL PREVAIL SAT...ALTHOUGH SOME RESTRICTIONS COULD
COME AS SHOWER AND THUNDERSTORM CHANCES WILL BE INCREASING SAT
NIGHT INTO SUNDAY...JUST BEYOND THE SCOPE OF THE TAF PERIOD.

OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
LOW PRESSURE WILL LIKELY BRING SHOWER/THUNDERSTORM RESTRICTIONS
LATE SAT NIGHT AND SUN. ADDITIONAL RESTRICTIONS ARE POSSIBLE MON AS
THE ASSOCIATED COLDFRONT CROSSES.

&&

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

&&

$$





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