FXUS61 KPBZ 231107
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
608 AM EST WED DEC 23 2009
.SYNOPSIS...
A SURFACE HIGH PRESSURE RIDGE WILL BUILD ACROSS THE REGION
TODAY...AND HOLD THROUGH THURSDAY. A WINTRY MIX WILL BE POSSIBLE
ON CHRISTMAS AS A LOW PRESSURE SYSTEM APPROACHES.
&&
.NEAR TERM /THROUGH TODAY/...
CLOUDS...ALONG WITH A BAND OF MAINLY FLURRIES IS CROSSING
EASTERN OHIO. THIS BAND MAY CLIP FAR SOUTHWEST PA AND NORTHERN
WEST VIRGINIA IN THE NEXT FEW HOURS. WITH ANY REPORTS OF SNOW
VERY LIGHT...WILL WORD SCATTERED FLURRIES THIS AM SOUTH OF PIT.
FURTHER NORTH...LAKE CLOUDS PUSHING DOWN FROM LAKES ERIE/HURON WILL
LIMIT SUNSHINE THIS MORNING. THE SURFACE RIDGE SHOULD BE ABLE TO
SUPPRESS THE CLOUD COVER BY THIS AFTERNOON...WITH SOME SUNSHINE
EXPECTED. MAX TEMPERATURES SHOULD BE AT OR BELOW FREEZING IN MOST
LOCATIONS TODAY
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
AFTER A PRIMARILY PARTLY CLOUDY NIGHT WITH TEMPS FALLING INTO THE
TEENS...CLOUDS WILL BE ON THE INCREASE THURSDAY...WITH TEMPS
MODERATING SOMEWHAT. CLOUD COVER...AND SNOW PACK WILL BE VARIABLES
IN MAX TEMP POTENTIAL THURSDAY. WITH THE LOW LEVEL FLOW OVER THE
SNOW PACK THURSDAY WITH WAA ALOFT...EXPECT SOME STRATUS/FOG COULD
FORM IN ADDITION TO THE HIGH CLOUDINESS EXPECTED AHEAD OF THE LOW
SYSTEM. THEREFORE...HAVE FAVORED MAXES CLOSER TO THE LOWER MET AS
OPPOSED TO MAV.
TEMPERATURES SHOULD HAVE A CHANCE TO FALL OFF THURSDAY
NIGHT...BEFORE THE BETTER WAA WORKS DOWN TO THE SURFACE DURING THE
DAY FRIDAY. LATEST FORECAST SOUNDINGS POINT TO A WINTRY MIX OF
FREEZING RAIN...RAIN AND POSSIBLY SLEET OVER PRIMARILY PA/WV
COUNTIES. LOOKS LIKE WARM ENOUGH FOR PRECIP TO START AS RAIN IN SE
OH AT THIS TIME. THE EASTERN/NORTHEAST COUNTIES WILL BE THE LAST
TO TURN OVER TO ALL RAIN FRIDAY AFTERNOON...AND THUS HAVE THE
GREATEST CHANCE FOR ACCUMULATIONS OF ICE. RIGHT NOW IT LOOKS LIKE
ACCUMS OF ICE WILL BE POSSIBLE...GENERALLY EAST OF I79. TOO EARLY
TO PIN DOWN EXACT LOCATIONS OR TIMING THOUGH...SO LATER SHIFTS
WILL DETERMINE ANY NEED FOR HEADLINES AS THE SYSTEMS EVOLUTION
BECOMES MORE CLEAR.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ON CHRISTMAS NIGHT STRONG CLOSED LOW OVER WESTERN LAKES WILL ALLOW
A SECONDARY LOW CENTER TO DEVELOP INLAND OF THE DELMARVA PENINSULA
WITH MOISTURE LOOKING TO BE THROWN BACK ACROSS EASTERN 2/3RD OF THE
CWA FRIDAY NIGHT INTO EARLY SATURDAY. HPC PROGS NOT TOO FAR OFF
00Z ECMWF AND 12Z GFS WITH THIS DEVELOPMENT. LOOKS TO BE A VERY
COMPLICATED SCENARIO SO FOR NOW BUMPED UP POPS TO LIKELY WITH A
MIX OF PRECIPITATION FRIDAY NIGHT TRANSITIONING TO ALL SNOW
EARLY SATURDAY MORNING... WITH SNOW DIMINISHING IN THE AFTERNOON
AS SURFACE LOW HEADS TO NEW ENGLAND. SUNDAY AND MONDAY CLOSED LOW
SLOWLY SLIDES EAST ACROSS UPPER OHIO VALLEY WITH BELOW NORMAL
TEMPERATURES AND SNOW SHOWERS. COLD SURFACE HIGH SHOULD ALLOW A
DRY DAY TUESDAY.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
LOW END VFR/MVFR CONDITIONS WILL LINGER FROM SOUTH OF PIT THROUGH
THIS MORNING...WITH A FEW FLURRIES PSBL. FURTHER NORTH...CLOUDS
STREAMING SOUTH FROM THE GREAT LAKES WILL RESULT IN AREAS OF MVFR
THIS AM FOR FKL AND POSSIBLY DUJ. BY THE AFTN...DRIER AIR WORKS IN
FOR ALL AREAS AS RIDGING BUILDS ACROSS THE REGION...WITH VFR THROUGH
THURSDAY EVENING AREA WIDE. EXPECT NORTH WINDS UNDER 7 KT FOR THE
NEXT 24 HOURS.
FOR THURSDAY NIGHT AND CHRISTMAS DAY...A SYSTEM WILL CROSS THE
AREA FROM THE SOUTHWEST. EXPECT MVFR TO IFR...WITH INITIAL PRECIP
A WINTRY MIX...CHANGING TO RAIN FOR MOST AREAS BY CHRISTMAS
AFTERNOON. AS THE SYSTEM EXITS TO THE NORTHEAST FRIDAY
NIGHT/SATURDAY...COLDER AIR WORKING IN WILL RESULT IN PRECIP
BECOMING SNOW AREA WIDE...WITH RESTRICTIONS PERSISTING THROUGH THE
WEEKEND.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
