Area Forecast Discussion
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FXUS61 KPBZ 242358
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
758 PM EDT THU JUL 24 2014

.SYNOPSIS...
DRY AND COOLER WEATHER WILL CLOSE THE WORK WEEK...WITH SHOWER AND
THUNDERSTORM CHANCES RETURNING FOR THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
DRIER AIR CONTINUES TO FILTER INTO THE REGION ON THE HEELS OF A
RATHER BRISK NORTHERLY FLOW. UPSTREAM DEWPOINTS REALLY FAIL TO
FALL OFF MUCH MORE THAN THEY ALREADY ARE IN NORTHWESTERN
PENNSYLVANIA...SO WHILE SURFACE HIGH PRESSURE IS FORECAST TO DROP
DIRECTLY OVER THE FORECAST AREA BY MORNING...EVEN WITH A DEARTH OF
WIND DURING THE PRIME RADIATIONAL COOLING HOURS...THERMAL FREE
FALL IS NOT REALLY EXPECTED. THAT SAID...CURRENT RESIDENT
DEWPOINTS TO OUR NORTH ARE GENERALLY IN THE UPPER 40S...SO
AREAWIDE MID 40 TO LOWER 50 DEGREE READINGS WILL BE FAIRLY
COMMON. THIS IS STILL FAR BELOW NORMAL FOR THIS TIME OF THE YEAR.

FOR REFERENCE...THE RECORD LOW FOR TONIGHT...51F FROM 1953. WILL
BE EXTREMELY CLOSE TO THAT READING BY MORNING AT THE AIRPORT.
FRIES

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
HIGH PRESSURE AT THE SURFACE AND NORTHWEST FLOW ALOFT WILL PROVIDE
A COMFORTABLE FRIDAY WITH PLENTY OF SUNSHINE.

MORE ZONAL FLOW IS PROJECTED BY SATURDAY IN RESPONSE TO LOW PRES
DIGGING TWD THE NRN PLNS. SWD DIPPING JET IS LIKELY TO INCRS DEEP
LYR SHEAR OVR THE REGION AND MAY SPPRT SVR TSTM CHCS SHOULD
TIMING/INSTABILITY PARAMETERS COOPERATE. FOR NOW...THE STORM
PREDICTION CENTER HAS TOUCHED THE UPR OH REGION WITH A SLGT
RISK...AND THAT SITUATION WL BE FURTHER EVALUATED DURING THE NXT
CPL OF DAYS AS CURRENT MDLS SUGGEST MRNG PASSAGE OF THE NECESSARY
SHRTWV SPPRT.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
PHASING OF THE AFOREMENTIONED LOW WITH A JAMES BAY LOW IS PROGGED
TO DVLP A HIGH AMPLITUDE TROF OVR THE ERN CONUS. FOLLOWING SHWR
CHCS UNDR THE IMMEDIATE CROSSING OF THE MID LVL TROF AXIS...THE
TREND IS OF DRY AND COOLER CONDITIONS.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
CLEAR SKIES AND CALM WINDS UNDER HIGH PRESSURE WILL LEAD TO THE
FORMATION OF VALLEY FOG TONIGHT. THE TERMINALS THE ARE TYPICALLY
IMPACTED BY VALLEY FOG COULD DROP IN VSBY TO 1/2 OR 1/4 SM. ATTM...LOWER
CONFIDENCE IN FOG DEVELOPMENT AWAY FROM RIVER VALLEYS TONIGHT...SO
EXPECTING TERMINALS INCLUDING PIT TO HAVE LIGHT MVFR FOG RESTRICTIONS.

ANY FOG THAT DEVELOPS TONIGHT WILL BURN OFF AFTER SUNRISE TOMORROW
WITH MOSTLY CLEAR SKIES AND VFR CONDITIONS.

OUTLOOK.../FRIDAY THROUGH MONDAY/...
RESTRICTIONS ARE LIKELY BY SUNDAY AS LOW PRES SPREADS SHWRS AND
TSTMS OVR THE UPR OH REGION. THE POTENTIAL WL CONT INTO MONDAY
WITH PASSAGE OF THAT SYSTEMS CDFNT.

&&

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

&&

$$






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