067
FXUS61 KPBZ 061156
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
656 AM EST TUE JAN 6 2026
SYNOPSIS
PASSING LOW PRESSURE BRINGS LIGHT RAIN TUESDAY INTO WEDNESDAY
MORNING. RAIN RETURNS THURSDAY NIGHT INTO SATURDAY. TEMPERATURES
CONTINUE TO WARM THROUGH THE WORK WEEK, REACHING WELL ABOVE
AVERAGE THURSDAY-SATURDAY BEFORE TEMPERATURES FALL BEHIND A COLD
FRONT SUNDAY INTO EARLY NEXT WEEK.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGES:
- DRY WEATHER CONTINUES INTO TUESDAY MORNING
- HIGH POP BUT LOW QPF RAIN EXPECTED TUESDAY INTO WEDNESDAY
MORNING
- ABOVE AVERAGE TEMPERATURES CONTINUE
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BY SUNRISE, THE UPPER RIDGE AXIS BEGINS TO SHIFT EASTWARD,
ALLOWING FOR SUBTLE HEIGHT FALLS AHEAD OF AN APPROACHING
SHORTWAVE TROUGH DIVING THROUGH THE OHIO VALLEY. AT THE SFC A
WEAK LOW PRESSURE SYSTEM CROSSES SOUTHERN ONTARIO. OUR POSITION
WELL SOUTH OF THIS SYSTEM PUTS US WELL INTO THE WARM SECTOR
BEHIND THE INITIAL WARM FRONT, CROSSING DURING THE AFTERNOON,
BEFORE A WEAK COLD FRONT SWEEPS THE REGION TUESDAY NIGHT INTO
WEDNESDAY MORNING.
MOIST ADVECTION PUSHES PWATS NEAR THE 90TH PERCENTILE, BUT WEAK
FORCING IN THE WARM SECTOR PRECLUDES HEAVY RAINFALL. THE
RESULTANT LIGHT SCATTERED RAIN SHOWERS AND PERIODS OF DRIZZLE
YIELDS QPF VALUES LIKELY (70-100% CHANCE) BELOW 0.25 INCHES.
A MORE STOUT SOUTHERLY FLOW AIDS WAA AT THE SFC WILL CONTINUE
OUR WARMING TREND AND PUSHING OUR HIGH TEMPERATURES BACK 10-15
DEGREES ABOVE AVERAGE FOR THIS TIME OF YEAR. AREAS SOUTH OF
PITTSBURGH GENERALLY HAVE A >60% CHANCE TO SEE HIGH TEMPERATURES
CRACK 50 DEGREES TODAY.
SHORT TERM /WEDNESDAY THROUGH THURSDAY/
KEY MESSAGES:
- LINGERING PRECIPITATION WEDNESDAY MORNING; MOSTLY DRY
THEREAFTER THROUGH THURSDAY
- ABOVE AVERAGE TEMPERATURES HOLD
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THE MAIN SHORTWAVE DEPARTS WEDNESDAY MORNING, WITH SURFACE HIGH
PRESSURE RIDING ACROSS THE MIDDLE OHIO VALLEY INTO THE
APPALACHIANS DURING THE DAY. LINGERING MOISTURE UNDERNEATH THE
SUBSIDENCE INVERSION MAY ALLOW FOR LINGERING LIGHT PRECIPITATION
DURING THE MORNING, FAVORING NORTH OF I-80 AND UPSLOPE-PRONE
AREAS. WEAK COLD ADVECTION SHAVES SEVERAL DEGREES OFF OF
TUESDAY'S HIGHS, BUT VALUES REMAIN ABOVE NORMAL.
DRY WEATHER CONTINUES THROUGH THURSDAY AS THE SURFACE HIGH MAINTAINS
INFLUENCE, AND AS 500MB HEIGHTS RISE OVER THE EASTERN CONUS IN
RESPONSE TO DEEPENING TROUGHING OVER THE INTERMOUNTAIN WEST. LOW-
LEVEL WARM ADVECTION SHOULD HELP TO SLOWLY ERASE LINGERING
STRATOCUMULUS FROM SOUTH TO NORTH WEDNESDAY NIGHT, BEFORE AN
INCREASE IN MID AND UPPER CLOUD COVER THURSDAY OVER THE CROSSING
RIDGE AXIS. AFTER WEDNESDAY NIGHT TEMPERATURES STRADDLING FREEZING
ACROSS THE REGION, MAXIMUMS JUMP ROUGHLY 10 DEGREES ON THURSDAY,
WITH LOWER AND MID 50S COMMON.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/
KEY MESSAGES:
- MILD WITH ROUNDS OF RAIN LIKELY THURSDAY NIGHT INTO SATURDAY
- EVENTUAL FRONTAL PASSAGE LEADS TO SEASONABLE CHILL RETURNING
WITH LIMITED SNOW POTENTIAL
- IMPACTS LIKELY LIMITED TO INCREASED WIND GUSTS, PENDING LOW
TRACK
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THE TROUGH TO OUR WEST ADVANCES EASTWARD INTO THE WEEKEND, LIKELY
CROSSING THE UPPER MIDWEST ON SATURDAY, AND THEN CROSSING THE UPPER
OHIO VALLEY INTO THE NORTHEAST CONUS ON SUNDAY. MODEL EXTENDED MODEL
SOLUTIONS/ENSEMBLES AGREE ON THIS LARGE-SCOPE PATTERN. MOIST
SOUTHWEST FLOW AND SHORTWAVES OUT AHEAD OF THE MAIN TROUGH AXIS
SUGGEST THAT ROUNDS OF RAIN ARE LIKELY DURING THE THURSDAY NIGHT
THROUGH SATURDAY PERIOD, ALONG WITH CONTINUED ABOVE-NORMAL
TEMPERATURES. A FRONTAL PASSAGE DURING THE WEEKEND, ACCOMPANIED
BY DEEPENING SURFACE LOW PRESSURE, PROMISES A RETURN TO A MORE
SEASONABLE CHILL AND PERHAPS LAKE-SUPPORTED SNOW SATURDAY NIGHT
INTO SUNDAY.
WHILE THAT OVERALL OUTLOOK IS GENERALLY AGREED ON, THE DETAILS
ARE NOT. ENSEMBLE CLUSTER ANALYSIS CONTINUES TO SUGGEST A RANGE
OF STRENGTH AND TIMING OUTCOMES REGARDING THE APPROACHING
TROUGH, WHICH COULD IMPACT FACTORS SUCH AS PRECIPITATION TIMING
AND WHEN THE ARRIVAL OF COLD AIR OCCURS. NEVERTHELESS, THERE
DOES NOT SEEM TO BE HIGH POTENTIAL FOR IMPACTS THAT WOULD DRIVE
LONG-FUSE HEADLINE ISSUANCES. 72-HOUR PROBABILITIES OF MORE
THAN ONE INCH OF RAINFALL THROUGH 7 AM SUNDAY ARE GENERALLY 30
PERCENT OR LESS ON THE NBM. THIS SUGGESTS LITTLE IN THE WAY OF
WATER CONCERNS, EVEN WHEN TAKING MELTING SNOW INTO ACCOUNT.
FOLLOWUP SNOW POTENTIAL FOR SATURDAY NIGHT THROUGH MONDAY IS
SIMILARLY UNIMPRESSIVE; PROBABILITIES FOR AN INCH OR MORE OVER
THAT PERIOD TOP OUT AT 20-30 PERCENT NORTH OF I-80 AND IN THE
HIGHER TERRAIN. LAKE INFLUENCES MAY BOOST THE NORTHERN TOTALS
SOMEWHAT, BUT AT THIS TIME, IMPACTFUL ACCUMULATION IS STILL A
LESS LIKELY OUTCOME. THE LONE EXCEPTION COULD BE WIND GUSTS THIS
WEEKEND, WITH HIGHER RIDGES POSSIBLY SEEING APPRECIABLE PEAK
VALUES. MORE WIDESPREAD CONCERNS WILL DEPEND ON THE STRENGTH,
TRACK, AND TIMING OF SURFACE LOW PRESSURE, BUT SUCH OUTCOMES DO
SEEM TO BE IN THE PROBABILITY SPACE AND WILL NEED TO BE
MONITORED.
AVIATION /12Z TUESDAY THROUGH SATURDAY/
KEY MESSAGES:
- AREA-WIDE VFR EXPECTED BEFORE RAIN RETURNS TUESDAY PM
- MVFR TO IFR RESTRICTIONS RETURN TUESDAY AS LOW PRESSURE
BRINGS RAIN TO THE REGION
------------------------------------------------------------
MOIST ADVECTION HELPS TO LOWER CLOUDS AHEAD OF AN IMPENDING
SHORTWAVE TROUGH CROSSING THE OHIO VALLEY. RAINFALL IS EXPECTED
TO BREAK OUT ACROSS THE REGION BY MIDDAY OR EARLY AFTERNOON AS
CIGS DEGRADE FIRST TO MVFR THEN IFR. RAINFALL IS EXPECTED TO
REMAIN ON THE LIGHTER SIDE, BUT LOW CIGS (IFR/LIFR) AND POCKETS
OF DRIZZLE COULD LOWER VIS FURTHER. RESTRICTIONS CONTINUE
THROUGH THE EVENING AND INTO THE OVERNIGHT AS THE SYSTEM CROSSES
THE REGION. WIDESPREAD RAIN BEGINS TO WIND DOWN BEHIND THE COLD
FRONT IN DRY ADVECTION LATE TONIGHT.
WINDS GRADUALLY SHIFT FROM SOUTHERLY TO SOUTHWESTERLY THROUGH
THE DAY AND THEN TO WESTERLY OVERNIGHT AS THE COLD FRONT CLEARS
THE REGION. A 30-35KT JET SETTLES ACROSS THE REGION FROM 20Z
TUESDAY - 04Z WEDNESDAY WHICH COULD BRING LLWS TO SOME LOCATIONS.
THIS SHEAR IS VERY SCATTERED AND SHORT-LIVED AT THIS TIME LLWS
HAS NOT BEEN INCLUDED IN TAFS.
OUTLOOK... RESTRICTIONS ARE EXPECTED TO CONTINUE INTO WEDNESDAY
AS LOW LEVEL MOISTURE REMAINS UNDER A TEMPERATURE INVERSION.
VFR RETURNS LATE WEDNESDAY AND THURSDAY UNDER HIGH PRESSURE.
POTENTIAL RESTRICTIONS AND RAIN RETURNS FRIDAY AND SATURDAY WITH
A SERIES OF CROSSING LOW PRESSURE SYSTEMS.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...AK
NEAR TERM...AK
SHORT TERM...CL
LONG TERM...CL
AVIATION...LUPO/AK
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