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Area Forecast Discussion
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000
FXUS61 KPBZ 300128
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
928 PM EDT WED OCT 29 2014

.SYNOPSIS...
A WEAK GREAT LAKES DISTURBANCE TONIGHT WILL BE FOLLOWED BY
BUILDING HIGH PRESSURE THURSDAY. LOW PRESSURE WILL BRING UNSETTLED
WEATHER FRIDAY AND SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
THE DRY SLOT HAS MOVED MOST OF ITS WAY THROUGH THE AREA...AND A
SHORT WAVE TROUGH EXTENDING SOUTH OF THE MID-LEVEL LOW OVER THE
GREAT LAKES IS BRINGING A CHANGE IN THE LOW LEVEL FLOW TO THE
NORTHWEST ACROSS THE REGION. THIS IS QUICKLY ALLOWING FOR CLOUDS
TO FILL BACK IN ACROSS OUR AREA. ADDITIONALLY...THIS SHOULD ALLOW
FOR A FEW SHOWERS TO AFFECT THE NORTHERN COUNTIES DOWNWIND FROM
LAKE ERIE AS LOW LEVEL FLOW CONTINUES ITS TREND TO THE NORTHWEST
OVER THE NEXT FEW HOURS AND SHEAR IN THE LOW LEVEL DECREASES.
DEEP ENOUGH SATURATION COMBINED WITH UPSLOPE MAY ALLOW FOR A
SPRINKLE IN THE RIDGES OVERNIGHT AS WELL...HOWEVER THE TIME FRAME
DURING WHICH THIS COULD OCCUR IS RATHER SHORT AS RIDGING QUICKLY
BUILDS IN TOWARD MORNING...ALLOWING FOR A RAPID INCREASE IN THE
SHEAR IN THE COLUMN AND A DEGRADATION OF THE CONDITIONS NECESSARY
FOR AN UPSLOPE SPRINKLE. THE REST OF THE FORECAST AREA WILL
LIKELY REMAIN DRY WITH ABUNDANT CLOUDS. FRIES

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
SFC HIGH PRES IS EXPD TO BLD IN UNDER BROAD UPR TROFG THU. THE UPR
TROF IS EXPD TO DEEPEN BY FRI AS AN ASSOCIATED SFC LOW AND CDFNT
ADVN ACRS THE RGN. THE DEEPENING TROF IS PROGGED TO DVLP INTO A
CLOSED LOW OVR THE OH VLY FRI NGT...MOVING OFF THE CAROLINA COAST
BY LT SAT. MOISTURE AND OMEGA ON THE NRN SIDE OF THE LOW IS EXPD
TO KEEP PCPN ACRS THE RGN INTO SAT. CRITICAL THICKNESSES AND
SOUNDING PROFILES INDICATE A RAIN/SNOW SHWR MIX BY FRI NGT INTO
SAT...OR EVEN A CHG OVR TO ALL SNW ESP IN THE RIDGES SE OF PIT.
SOME LGT ACCUMS ARE PSBL MAINLY IN THE COLDER HIGHER TERRAIN
LOCATIONS...THOUGH VRY LTL UPSLOPE FLOW COMPONENT IS EXPD WITH
N-NNE WNDS SAT. PCPN CHCS SHOULD BE DCRG LTR SAT AS THE UPR LOW
BEGINS TO EXIT OFF THE COAST.

TEMPS SHOULD AVG 5-10 DEG BLO SEASONAL LVLS LT THIS WK...AND ARND
15 DEG BLO SEASONAL LVLS SAT.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
WPC SUGGESTS FOLLOWING ENSEMBLE MEANS IN THIS ANOMALOUS PATTERN AND 
SEE NO REASON TO DISAGREE.  HIGH PRESSURE WILL BUILD IN BEHIND THE 
DEPARTING DEEP SYSTEM.  WITH THE NORTHEAST TROUGH HANGING AROUND 
THROUGH THE WEEKEND...TEMPERATURES WILL CONTINUE TO RUN WELL BELOW 
NORMAL.  SATURDAY NIGHT MAY BE THE COLDEST OF THE SEASON THUS FAR 
WITH WIDESPREAD READINGS IN THE 20S.  MODERATION CAN BE EXPECTED FOR 
MONDAY AND TUESDAY AS RIDGING DEVELOPS ONCE AGAIN.  THE NEXT FRONT 
MAY ARRIVE COME TUESDAY NIGHT OR WEDNESDAY WITH RAIN SHOWER CHANCES.

&&

.AVIATION /02Z THURSDAY THROUGH MONDAY/...
GENERAL VFR FORECAST THROUGH THE OVERNIGHT AND THURSDAY. USING A
BLEND OF LATEST OBS AND MODEL DATA...MOST SITES SHOULD REMAIN JUST
INTO THE VFR CAT AS LARGE STRATOCU DECK DESCENDS OVER THE AREA
WITH THE NEXT SHOT OF COLDER AIR. WILL PUSH FKL AND DUJ INTO THE
MVFR CAT WITH THE CLOUD DECK.

COLDER AIR WILL SLOWLY LIFT NORTHWARD THURSDAY ALLOWING FOR
STRATOCU DECK TO EVENTUALLY THIN OUT. 

OUTLOOK.../THURSDAY NIGHT THROUGH MONDAY/...
WIDESPREAD RESTRICTIONS ARE EXPECTED ON FRIDAY AS DEEPENING LOW
PRES IS PROJECTED TO SHUNT A BROAD MSTR SWATH OVR THE UPR OH
REGION. ENSUING COLD ADVCTN WL THEN MAINTAIN STRATOCU POTENTIAL
UNTIL SFC HIGH STRENGTHENS ON SUNDAY.

&&

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

&&

$$






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