-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KPBZ 051127
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
627 AM EST SUN FEB 5 2012

.SYNOPSIS...
-- Changed Discussion --ANY REMAINING MIX OF LIGHT RAIN AND SNOW ACROSS THE MOUNTAINS WILL
END THIS MORNING, AS UPPER LEVEL DISTURBANCE EXITS EAST. HIGH
PRESSURE, COMING EAST FROM THE PLAINS, WILL THEN FOLLOW TO BRING SUNSHINE
BY AFTERNOON, AND AGAIN ON MONDAY.-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --RECENT RADAR DATA TRENDS AND HRRR AND WRF-NMM MODEL OUTPUT
CONTINUE TO SHOW ANY LIGHT MIX OF RAIN AND WET SNOW ACROSS THE
SOUTH EAST RIDGES WILL END BEFORE MID-MORNING, AS AN UPPER LEVEL
JETSTREAM MAX EXITS EAST. THERE MAY BE A SMALL ACCUMULATION OF WET
SNOW OVER THE HIGHER MOUNTAINS.

RECENT SURFACE DATA SHOWS SIGNS THAT THE LOW CLOUDS RESULTING IN
FOG PATCHES OVER THE HIGHER PA-WV-MD MOUNTAINS, HAS BEGUN TO LIFT. SO
EXPECT ANY REMAINING HIGHER ELEVATION FOG TO HAVE ENDED BY 9 AM.

PER TRENDS IN RECENT SATELLITE DATA AND SUPPORT FROM RECENT HRRR
AND NAM MODEL OUTPUT, EXPECT CLOUDS TO ALSO DECREASE, NORTH TO
SOUTH, THIS MORNING, YIELDING A DECENT AMOUNT OF SUNSHINE BY AFTERNOON.

HAVE CONTINUED TO FINE TUNE TEMPERATURE FORECAST PER RECENT HRRR
AND GFS LAMP MODEL OUTPUT. EXPECT AFTERNOON HIGHS TO BE 2 TO 5
DEGREES WARMER THAN NORMAL, WHICH IS ALSO SUPPORTED BY RECENT NAM
AND GFS MOS.-- End Changed Discussion --

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
BLEND OF RECENT SREF AND ECMWF MODEL OUTPUT SHOWS SPRAWLING HIGH
PRESSURE, EXTENDING FROM THE PLAINS TO THE APPALACHIANS, WILL
PROVIDE NO MORE THAN SCATTERED CLOUDS ACROSS THE UPPER OHIO VALLEY
TONIGHT INTO TUESDAY. THIS WILL MAINTAIN MILD CONDITIONS, WITH
LOWS AND HIGHS GENERALLY 5 TO 8 DEGREES WARMER THAN NORMAL.

MODELS THEN SHOW STRONG HIGH PRESSURE SPREADING SOUTHEASTWARD FROM
THE CANADIAN PLAINS. THIS WILL PUSH A COLD FRONT SOUTHWARD THROUGH
THE UPPER OHIO VALLEY TUESDAY NIGHT INTO WEDNESDAY. THE FRONT MAY
HAVE LITTLE MOISTURE TO INGEST, SO MAINTAINED A SLIGHT CHANCE OF
PREFRONTAL SHOWERS TUESDAY NIGHT, AND A CHANCE OF POSTFRONTAL SHOWERS
WEDNESDAY.

THE PRECIPITATION TYPE WILL BE A MIX OF RAIN AND SNOW, AS SURFACE
LAYER TEMPERATURES WILL STRADDLE THE FREEZING POINT. THIS IDEA IS
SUPPORTED BY RECENT GFS AND NAM MOS WHICH SHOW TEMPERATURES TO
LOWER TO SEASONABLE LEVELS.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOWS A DEEP UPPER
LOW PASSING EASTWARD THROUGH EASTERN CANADA LATE WEEK. HENCE
EXPECT A COLD FRONT, WITH A MIX OF RAIN AND SNOW SHOWERS, TO PASS
THROUGH THE UPPER OHIO VALLEY AROUND FRIDAY. FOR NOW HAVE
CONTINUED FORECAST OF NEAR-SEASONABLE POSTFRONTAL TEMPERATURES FOR
SATURDAY. HOWEVER, RECENT NAEFS MEDIAN VALUES AND GFS MOS SUGGEST
TEMPERATURES SATURDAY COULD BECOME 5 TO 10 DEGREES COLDER THAN
NORMAL.

&&

.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --DRY AIR WORKING IN FROM THE NORTH IS PROHIBITING MUCH FOG OR
STRATUS DEVELOPMENT EARLY THIS MORNING EXCEPT FOR KMGW AND THE
MOUNTAINS EAST. ANY PATCHY MVFR FOG WILL QUICKLY BURN OFF AFTER
SUNRISE. AS UPPER TROUGH EXITS EAST THIS MORNING FOG AND STRATUS
FROM MGW AND RIDGES WILL LIFT WITH REMAINING MID DECK QUICKLY
SHIFTING EAST. WINDS WILL BE LIGHT NORTHERLY INTO THE AFTERNOON.

OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
GENERAL VFR CONDITIONS ARE EXPECTED THROUGH TUESDAY. A SERIES OF
SHORT WAVES MAY BRING RESTRICTIONS AT TIMES IN SNOW SHOWERS
WEDNESDAY INTO THURSDAY.-- End Changed Discussion --

&&

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

&&

$$

NWS PBZ Office Area Forecast Discussion