FXUS61 KPBZ 260004
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
704 PM EST FRI DEC 25 2009
.SYNOPSIS...
A STRONG STORM SYSTEM OVER THE MIDWEST WILL MOVE SLOWLY EASTWARD
ACROSS THE LOWER GREAT LAKES THIS WEEKEND. RAIN WILL GRADUALLY TAPER
OFF BY SATURDAY MORNING. SCATTERED SNOW SHOWERS WILL RETURN ON
SUNDAY AS COLDER AIR MOVES BACK INTO THE UPPER OHIO VALLEY.
&&
.NEAR TERM /THROUGH SATURDAY/...
LARGE AREA OF PRECIPITATION WILL CONTINUE TO SLIDE NORTHEAST
OF THE FORECAST AREA TONIGHT. RAIN IS EXPECTED TO TAPER OFF AS
DRY SLOT PUSHES IN FROM THE WEST LATER TONIGHT.
COLDER AIR WILL MOVE IN BEHIND SURFACE FRONT BY SATURDAY MORNING.
ANY LEFT OVER PRECIPITATION WILL MIX WITH SNOW BUT LITTLE OR NO
ACCUMULATION IS EXPECTED. TEMPERATURES HOLD IN THE LOWER TO MID
30S OVERNIGHT...AND THEN WARM TO THE MID 30S TO LOWER 40S
SATURDAY.
WILL CONTINUE WIND ADVISORIES FOR THE RIDGES THROUGH EARLY EVENING
AS STRONG PRESSURE GRADIENT REMAINS ACROSS THE REGION.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
MOST OF THE FORECAST AREA WILL REMAIN DRY SATURDAY NIGHT WITH A DRY
SLOT HOLDING OVER THE REGION. MOISTURE WILL RETURN DURING SUNDAY AS THE
UPPER LOW BEGINS TO MAKE SLOW EASTWARD PROGRESS OVER THE LOWER
GREAT LAKES. MIXED RAIN AND SNOW SHOWERS ARE FORECAST SOUTH WHERE
SUNDAY AFTERNOON TEMPERATURES REACH THE UPPER 30S...WITH MAINLY
SNOW SHOWERS NORTH BUT LITTLE ACCUMULATION.
WENT WITH LIKELY POPS FOR SUNDAY NIGHT INTO MONDAY MORNING AS
UPPER LOW CROSSES TO OUR NORTH AND TRACKS TOWARD NEW ENGLAND.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
UPPER LEVEL LOW OVER THE LOWER GREAT LAKES WILL MOVE INTO NEW
ENGLAND MONDAY. PERSISTENT LOW LEVEL NORTHWEST FLOW AND COLD AIR
INSTABILITY WILL CONTINUE TO GENERATE SCATTERED SNOW SHOWERS
THROUGH MONDAY NIGHT.
SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION TUESDAY AND
WEDNESDAY BRINGING DRY WEATHER. A LOW PRESSURE SYSTEM OVER THE
SOUTHEASTERN STATES WILL BRING MOISTURE AND A CHANCE OF SNOW
SHOWERS TO THE THE FORECAST AREA FOR WEDNESDAY NIGHT INTO THURSDAY.
ANOTHER WEAK SHORT WAVE WILL BRING MORE SNOW SHOWERS FOR FRIDAY.
CLOUD COVER WILL HOLD DAYTIME TEMPERATURES DOWN TO FEW DEGREES BELOW
NORMAL THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
A STRONG LOW PRESSURE SYSTEM WILL REMAIN ACROSS THE MIDWEST...WITH
ASSOCIATED SHOWERS MOVING ACROSS THE TERMINALS OVERNIGHT. THE
FIRST ROUND OF SCATTERED SHOWERS WILL ADVECT NORTHEAST OF
KDUJ/KFKL THIS EVENING AND THEN SHOWERS ASSOCIATED WITH A
CONVERGENT ZONE WILL PUSH ACROSS THE TERMINALS PRIOR TO THE PRE-
DAWN HOURS. WITH THE CONVERGENT ZONE...RAIN MAY BECOME HEAVY AT
TIMES...WITH SOUTHEAST WINDS SHIFTING TO SOUTHWEST AND GUSTING
AROUND 25 KTS. THE WIND SHIFT AND HEAVIER RAIN WILL OCCUR FIRST AROUND
03Z AT KZZV...REACHING KPIT AROUND 06Z...AND FINALLY KDUJ/KFKL BY
DAWN. CEILINGS AND VISIBILITIES WILL BECOME MVFR ACROSS MOST OF THE
TERMINALS AND MAY DROP TO IFR AT TIMES AS THE SHOWERS ADVECT ACROSS THE
AREA OVERNIGHT. IFR CEILINGS WILL BE MORE LIKELY TO PREVAIL AT
KFKL/KDUJ.
LOW-LEVEL WIND SHEAR WILL CONTINUE TO BE POSSIBLE ACROSS
THE TERMINALS THIS EVENING...WITH A LOW-LEVEL JET EXITING
NORTHEAST OF THE AREA AND LLWS DIMINISHING BY 09Z ACROSS THE TAF
SITES.
HIGH PRESSURE WILL BUILD IN FROM THE SOUTH ON SATURDAY...WITH
CEILINGS BECOMING VFR BY LATE MORNING ACROSS THE AREA. THERE IS
THE CHANCE FOR A FEW SNOW SHOWERS ACROSS THE NORTHERN
TERMINALS ON SATURDAY...ALTHOUGH CONFIDENCE IS NOT HIGH ENOUGH TO
MENTION IN THE TAFS AT THE MOMENT. AN UPPER LEVEL LOW WILL
ADVECT INTO THE EASTERN GREAT LAKES ON SUNDAY AND INTO THE
NORTHEAST ON MONDAY. THIS WILL ALLOW FOR THE POSSIBILITY OF SNOW
SHOWERS WITH REDUCED CEILINGS AND VISIBILITIES. HIGH PRESSURE WILL
BUILD INTO THE AREA LATE ON TUESDAY...WITH VFR CONDITIONS
PREVAILING INTO WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND ADVISORY UNTIL 8 PM EST THIS EVENING FOR MDZ001.
OH...NONE.
PA...WIND ADVISORY UNTIL 8 PM EST THIS EVENING FOR PAZ030-032.
WV...WIND ADVISORY UNTIL 8 PM EST THIS EVENING FOR WVZ023-041.
&&
$$
