372
FXUS61 KPBZ 160857
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
357 AM EST MON DEC 16 2024
SYNOPSIS
DRY WITH WARMING TEMPERATURES THIS MORNING, BEFORE RAIN RETURNS
THIS AFTERNOON AHEAD OF THE NEXT SYSTEM. THE ENTIRE WEEK LOOKS
UNSETTLED. COLDER TEMPERATURES MOVE IN FOR LATE IN THE WEEK.
NEAR TERM /UNTIL 6 PM THIS EVENING/
KEY MESSAGES:
- WARMER TEMPERATURES AND RAIN RETURNING THIS AFTERNOON.
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A 500MB RIDGE WILL MOVE ACROSS THE REGION THIS MORNING. THIS
RIDGE WILL PROVIDE A RESPITE FROM THE RAIN AND ALSO SPREAD MUCH
WARMER AIR ACROSS THE REGION. THE BREAK FROM THE RAIN WILL BE
SHORT LIVED AS THE NEXT SHORTWAVE TROUGH WILL DIG INTO THE UPPER
OHIO VALLEY THIS AFTERNOON. RAIN WILL OVERSPREAD THE REGION
FROM WEST TO EAST IN CONJUNCTION WITH THE WARMER AIR. HIGHS
TODAY WILL BE 10 TO 15 DEGREES ABOVE NORMAL.
PROBABILITIES OF RAINFALL > 0.30 INCHES TODAY RANGE FROM 40 TO
80% WITH THE HIGHER VALUES OVER OHIO.
SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/
KEY MESSAGES:
- RAIN ENDS EARLY TUESDAY.
- ABOVE NORMAL TEMPERATURES TUESDAY.
- RAIN CHANCES RETURN AGAIN ON WEDNESDAY.
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A SURFACE COLD FRONT, TRAILING TODAY'S SHORTWAVE TROUGH WILL
SWING THROUGH THE REGION TONIGHT. ONCE THE BOUNDARY EXITS TO
THE EAST, DRIER AIR WILL OVERSPREAD THE REGION BRINGING AN END
TO THE THREAT FOR RAIN. COLD AIR ADVECTION BEHIND THE FRONT WILL
DROP TEMPERATURES ABOUT 5 TO 10 DEGREES ON TUESDAY, BUT READINGS
WILL REMAIN ABOVE NORMAL.
EXPECT TO SEE A DECREASE IN CLOUD COVER ON TUESDAY.
UNCERTAINTY THEN RAMPS UP QUICKLY WITH TIMING AND STRENGTH OF A
SECOND, DEEPER TROUGH APPROACHING FROM THE CENTRAL CONUS LATE
TUESDAY NIGHT. SOME MODELS HOLD IT BACK WITH OTHERS EVEN
KEEPING IT POSITIVE/NEUTRAL TO OUR WEST ON WEDNESDAY EVENING.
CHANCE FOR MEASURABLE PRECIPITATION WILL BEGIN WEDNESDAY
AFTERNOON/EVENING AND CEASE AROUND THURSDAY MORNING/EARLY
AFTERNOON.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/
KEY MESSAGES:
- TEMPERATURES COOLING INTO THE 20S-30S BY THE END OF THE WEEK
AND INTO THE WEEKEND.
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THERE IS UNCERTAINTY WITH HOW FAST THE UPPER LEVEL TROUGH MOVES OUT
OF THE AREA AS A SHORTWAVE TROUGH IS EXPECTED TO MOVE INTO THE AREA
ON FRIDAY AND LINGER THROUGH LATE SATURDAY BRINGING ANOTHER CHANCE
OF RAIN.
TEMPERATURES ARE EXPECTED TO COOL ON THURSDAY. TEMPERATURES IN
THE LOW 30S WILL PERSIST THROUGH FRIDAY AND THEN COOL INTO THE
MID-20S BY SATURDAY.
AVIATION /09Z MONDAY THROUGH FRIDAY/
A MIX OF IFR/LIFR CEILINGS (MVFR CLOSER TO THE RIDGES DUE TO
DOWNSLOPING WINDS) HAS SET UP ACROSS THE AREA AS RAIN SHOWERS
GRADUALLY DEPART TO THE EAST OVER THE FIRST FEW HOURS OF THE TAF
PERIOD. ADDITIONALLY, SOME PATCHY FOG HAS DEVELOPED IN A FEW OF
THE COMMON SPOTS LIKELY DUE TO SATURATED GROUNDS AND LINGERING
LOW-LEVEL MOISTURE. IMPROVEMENTS IN VISIBILITY ARE EXPECTED
STARTING IN THE 08Z-10Z TIMEFRAME, ONCE SHOWERS HAVE DEPARTED
AND LINGERING MIST/DRIZZLE TAPERS OFF. CEILINGS LIKEWISE SEE
MINOR IMPROVEMENTS THROUGH MONDAY MORNING, THOUGH LATEST HREF
GUIDANCE MAINTAINS 50-80% PROBABILITIES FOR IFR NORTH OF I-80
(FKL/DUJ) AND IN AREAS WEST/NORTHWEST OF PIT (NAMELY BVI AND
ZZV). ELSEWHERE, MVFR IS MORE LIKELY BY THE 14Z-19Z TIMEFRAME.
THIS IMPROVEMENT WILL BE SHORT-LIVED, HOWEVER, AS A BROAD,
ORGANIZED RAIN SHIELD IS EXPECTED TO RETURN FROM THE WEST
BEGINNING AROUND 16Z AT ZZV AND CLOSER TO 19-20Z FOR PIT AND
AREAS EAST. THIS WILL BRING ANOTHER DROP IN CIGS/VSBYS WITH
PROBABILITIES FOR IFR OR WORSE INCREASING TO 70-90% AREAWIDE
SAVE FOR THOSE RIGHT ALONG THE RIDGES.
AS WE APPROACH 00Z, THE NOSE OF A 40-50KT LOW-LEVEL JET WILL BE
PRESSING INTO THE REGION FROM THE WEST WHICH COULD BRING SOME
LLWS CONCERNS TO AREA TERMINALS DURING OVERNIGHT HOURS. RAIN
SHOULD TAPER FROM WEST TO EAST AFTER 03Z, ALLOWING SOME
IMPROVEMENT IN VISIBILITIES TOWARDS THE TAIL END OF THE TAF
PERIOD, THOUGH LOW CEILINGS WILL LINGER.
OUTLOOK...
HIGH PRESSURE AND A SHORT-LIVED RETURN OF VFR ARE EXPECTED
TUESDAY BEFORE ANOTHER WEATHER SYSTEM BRINGS PRECIPITATION AND
RESTRICTIONS BACK TO THE AREA MID TO LATE WEEK.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...22
NEAR TERM...22
SHORT TERM...22/LUPO
LONG TERM...LUPO
AVIATION...CERMAK/LUPO/AK
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