FXUS61 KPBZ 052215
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
515 PM EST SAT DEC 5 2009

.SYNOPSIS...

BUILDING HIGH PRESSURE WILL BRING DRY AND COLD CONDITIONS FOR
SUNDAY. THERE WILL BE A CHANCE OF SOME SNOW SHOWERS ON MONDAY AS A
WEAK DISTURBANCE CROSSES THE REGION...BUT THE BEST CHANCE FOR
WIDESPREAD WINTRY PRECIPITATION WILL COME WITH A MID WEEK LOW
PRESSURE SYSTEM.

&&

.NEAR TERM /THROUGH SUNDAY/...

SNOW DIMINISHED SUFFICIENTLY TO DROP THE EXTRA PRODUCTS WITH AN
EARLY EVENING UPDATE. SNOWFALL WILL RAPIDLY EXIT THE REGION
COMPLETELY AS THE EVENING PROGRESSES...WITH THE CONTINUED
NORTHEASTWARD TREK OF THE LOW. THE SKY WILL CLEAR FOR MOST AREAS
THIS EVENING/OVERNIGHT...EXCEPT FAR NORTH WHERE COLD W/NW FLOW
WILL RESULT IN CLOUDS PERSISTING NORTH OF I-80. HIGH PRESSURE WILL
BUILD ACROSS THE AREA SUNDAY FOR MOSTLY SUNNY SKIES...BUT WITH A
COLD AIRMASS REMAINING IN PLACE...EXPECT BELOW NORMAL TEMPERATURES
TO CONTINUE...ESPECIALLY OVER THE RIDGES WHERE SNOW COVER WILL
SUPPORT A DROP TO NEAR SINGLE DIGITS.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
LOW AMPLITUDE RIDGING WILL PUSH TO THE EAST SUNDAY NIGHT...WITH A
SHORT WAVE TROUGH CROSSING THE AREA MONDAY/MONDAY NIGHT. DEEP
MOISTURE IS QUITE LIMITED...AND WITH THE GREATEST FORCING TO
THE NORTH...WILL KEEP POPS LOW END CHANCE FOR MONDAY/MONDAY
NIGHT. TUESDAY SHOULD BE MAINLY DRY AS SHORT WAVE RIDGING
CROSSES THE REGION. SLIGHTLY BELOW NORMAL TEMPERATURES WILL
CONTINUE.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
WARM ADVECITION ALOFT AHEAD OF AN APPROACHING LOW TUESDAY
NIGHT IS EXPECTED TO PRODUCE A WINTRY MIX OF PRECIPITATION.
CURRENT FORECASTS OF THERMAL PROFILES SUGGEST THAT A BAND OF
SLEET/FREEZING RAIN COULD DEVELOP AND MOVE NORTH ACROSS THE
FORECAST AREA TUESDAY NIGHT INTO EARLY WEDNESDAY. AS WARM AIR SURGES
NORTHWARD ON THE EASTERN FLANK OF GREAT LAKES LOW PRESSURE, A
CHANGE TO RAIN IS EXPECTED. THE SYSTEMS COLD FRONT IS THEN PROGGED
TO CROSS THE UPPER OHIO ON WEDNESDAY NIGHT AND CHANGE REMAINING
PRECIP OVER TO SNOW. A COLD AND BLUSTERY DAY IS FORESEEN FOR
THURSDAY WITH LAKE EFFECT SNOW SHOWERS.

HIGH PRESSURE SHOULD BUILD OVER THE REGION BY FRIDAY, BUT WITH ZONAL
FLOW ALOFT, EXPECT SHORTWAVES TO MOVE THROUGH THE FLOW, AND HAVE
THUS KEPT POPS IN THE LATER PERIODS.

&&

.AVIATION /22Z SATURDAY THROUGH THURSDAY/...

RAPID IMPROVEMENT TO VFR IS EXPECTED AT MOST PORTS EARLY THIS
EVENING AS LAST OF THE SNOWFALL PROGRESSES EASTWARD. HOWEVER,
REPRIEVE MAY BE SHORT AS REDUCED CONDITIONS/STRATOCUMULUS ADVECT
OVER UPPER OHIO TERMINALS WITH THE COLDER AIR TO THE
WEST...ESPECIALLY AT FKL AND DUJ.

HIGH PRESSURE COMING BUILDING OUT OF THE MIDWEST WILL PROVIDE VFR
ACROSS THE UPPER OHIO VALLEY FOR THE START OF THE NEW WEEK. A
CROSSING DISTURBANCE MAY GENERATE A PERIOD OF MVFR RAIN AND SNOW
LATE MONDAY INTO MONDAY NIGHT. ANOTHER LOW WILL THEN AFFECT THE
REGION FROM TUESDAY NIGHT INTO WEDNESDAY...WITH A WINTRY MIX OF
PRECIPITATION EXPECTED. A PERIOD OF FREEZING RAIN AND SLEET WILL
BE POSSIBLE TUESDAY NIGHT...AND EARLY IN THE DAY WEDNESDAY.

&&

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

&&

$$

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