FXUS61 KPBZ 021112
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
611 AM EST WED DEC 2 2009
.SYNOPSIS...
A DEEPENING STORM SYSTEM WILL BRING RAIN TO THE REGION LATER TODAY
AND INTO EARLY THURSDAY. COLDER AIR WILL MOVE IN FOR THE END OF
THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
DEEPENING SFC LOW WILL SLOWLY MOVE UP THE TN AND LOWER OHIO VALLEY
TODAY. LOW WILL WIND UP AS UL ENERGY DIGS INTO W KY THIS
AFTERNOON. WITH TRACK OF LOW...WARMER AIR WILL MOVE UP THE EASTERN
US AS MUCH COLDER AIR DIGS INTO THE N GREAT LAKES AND UPPER
MIDWEST. IT WILL TAKE A BIT OF TIME TO MOISTEN THE LOWER
ATMOSPHERE...BUT EXPECT ALL LOCATIONS TO SEE RAIN BY LATE
AFT/EARLY EVE. LOCATIONS NORTH OF I-80 WILL STAY DRY THE LONGEST.
SFC WINDS WILL INCREASE THIS AFTERNOON IN RESPONSE TO TIGHTENING
SFC PRES GRADIENT. VERY STRONG WINDS...AROUND 2000FT AND ABOVE ARE
EXPECTED LATE THIS MORNING AND THROUGH THE AFT AS 85H LOW MOVES
INTO THE OHIO VALLEY. WILL ISSUE A WIND ADVISORY FOR MY RIDGE
COUNTIES OF W MD AND N WV.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
DIFFERING SOLUTIONS ON TRACK OF LOW TONIGHT WITH NAM BEING FURTHER
WEST THAN GFS. THE TRACK OF THE SFC LOW WILL BE IMPORTANT FOR THE
LOCATION OF TONIGHTS DRY SLOT. THE NAM SOLUTION WOULD BRING THE
DRY SLOT THROUGH THE REGION THIS EVENING WHILE THE GFS SOLUTION
KEEPS THE DRY SLOT WELL EAST OF THE AREA. WILL LEAN TOWARD THE GFS
SOLUTION AS IT IS CLOSER IN AGREEMENT WITH 21Z SREF/12Z ECMWF.
RAIN WILL CONTINUE INTO EARLY THU MORNING. SFC LOW CONTINUES TO
DEEPEN TONIGHT AND ALSO SPEED UP AS UL WAVE MOVES QUICKLY THROUGH
W PA. BACK EDGE OF RAIN SHOULD REACH PIT CLOSE TO 12Z THU AND
CLEAR THE NORTH BY LATE THU MORNING.
MUCH COLDER AIR WILL MOVE IN BEHIND EXITING SYSTEM ON THU. WIND
DIRECTION IS NOT OPTIMAL FOR LES THU AND LL THICKNESS NOT COLD
ENOUGH UNTIL LATE IN THE DAY TO SUPPORT ALL SNOW. EXPECT TO SEE
SNOW FIRST ON THE HIGHEST ELEVATIONS AS 85H TEMPS DROP BELOW -3 BY
LATE AFTERNOON. MID LEVEL WIND DIRECTION HAS MORE OF A WESTERLY
COMPONENT WHICH WILL BE MORE CONDUCIVE TO UPSLOPE PRECIP THU AND
ACROSS THE FAR NORTH. WILL KEEP IN CHC FOR SHOWERS ACROSS MOST OF
THE REGION THU BUT THIS MAY BE OVERDOING IT. THIS WILL HAVE TO BE
ADDRESSED IN LATER FORECASTS.
STRONG CAA CONTINUES INTO FRIDAY BUT MID LEVEL WINDS BEGIN TO GO
MORE SOUTHWESTERLY AND 50H LOW REMAINS WELL NORTH OF THE REGION.
THIS WILL CONTINUE THE RISK FOR UPSLOPE SNOW SHOWERS BUT WILL NOT
PROVIDE A SHOT AT LES. EXPECT PLENTY OF CLOUDS AND COLD TEMPS
FRIDAY WITH THE STRONG MID LEVEL CAA.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
COLDER PATTERN WILL CONTINUE FOR THE REMAINDER OF THE LONG TERM
PERIOD. HOWEVER LARGE SFC HIGH WILL PROVIDE A MAINLY DRY PERIOD AS
WELL.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
CIRRUS CONTINUES TO OVERSPREAD THE REGION EARLY THIS MORNING.
CEILINGS WILL LOWER AND THICKEN LATER THIS MORNING...WITH INITIAL
PRECIP BEGINNING AT MGW AROUND NOON...TO PIT EARLY AFTN...AND TO
DUJ/FKL BY LATE AFTN. CONDITIONS WILL WORSEN TO IFR FOR MOST AREAS
WED EVENING. S/SE WINDS 3-6 KT OVERNIGHT WILL BECOME SOUTHEAST
AROUND 10 KT THIS AFTN...WITH GUSTS OF 20-25 KT LATE AFTN/EVENING.
WITH WINDS ALOFT INCREASING SIGNIFICANTLY...ESPECIALLY EAST...TO
40-50 KT AT 2000 FEET BY EVENING...WILL INCLUDE LLWS FOR LBE/MGW FOR
LATE THIS AFTN THROUGH THE EVENING HOURS.
RESTRICTIONS WILL CONTINUE THROUGH AT LEAST THURSDAY AS LOW PRESSURE
GRADUALLY PUSHES TO THE NORTHEAST. POST SYSTEM COLD ADVECTION WILL
MAINTAIN AREAS OF MVFR STRATOCUMULUS ACROSS THE REGION INTO THE
WEEKEND. HIGH PRESSURE IS PROGGED TO CROSS THE REGION SUNDAY WITH
MAINLY DRY/VFR CONDITIONS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND ADVISORY FROM 9 AM THIS MORNING TO 9 PM EST THIS EVENING
FOR MDZ001.
OH...NONE.
PA...NONE.
WV...WIND ADVISORY FROM 9 AM THIS MORNING TO 9 PM EST THIS EVENING
FOR WVZ023-041.
&&
$$
