809
FXUS61 KPBZ 081919
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
219 PM EST SAT NOV 8 2025
SYNOPSIS
A BRIEF PERIOD OF DRY WEATHER IS EXPECTED THIS AFTERNOON BEFORE
ANOTHER SHORTWAVE TROUGH DIVES INTO THE REGION TONIGHT. THIS
WILL BRING A ROUND OF SHOWERS ON SUNDAY, CHANGING TO SNOW
SHOWERS SUNDAY NIGHT.
NEAR TERM /THROUGH SUNDAY/
KEY MESSAGES:
- DRY CONDITIONS THROUGH THE AFTERNOON
- RAIN CHANCES INCREASE TONIGHT INTO SUNDAY
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A SHORTWAVE RIDGE TRANSITIONING OVER THE REGION TODAY WILL
RESULT IN DRY CONDITIONS UNDER INCREASING SUBSIDENCE. AFTER SOME
CLEARING AND DRYING OUT FROM THE DENSE FOG EARLIER, CLOUD COVER
HAS CLEARED A BIT AS WELL. THIS HAS ALLOWED TEMPERATURES TO
WARM INTO THE MID AND UPPER 50S. HEADING INTO TONIGHT, THE
DEEPENING UPPER TROUGH IS PROGGED TO DIG ACROSS THE UPPER
MIDWEST AND WESTERN GREAT LAKES OVERNIGHT AND SUNDAY. MEANWHILE,
SURFACE LOW PRESSURE WILL DEEPEN AS IT TRACKS UP THE OHIO RIVER
VALLEY. WHILE THERE IS A MINIMAL CHANCE OF BRIEF LIGHT RAIN
ACROSS NORTHERN ZONES THIS EVENING WITH A WEAK SHORTWAVE, RAIN
CHANCES WILL SUBSTANTIALLY RAMP UP ACROSS MUCH OF THE AREA
SUNDAY MORNING AS THE SURFACE LOW TRAVERSES THE EASTERN GREAT
LAKES AND DRAGS ITS TRAILING COLD FRONT ACROSS THE REGION.
PRECIPITATION ON SUNDAY WILL MAINLY BE LIQUID WITH THE NBM PROBS
ADVERTISING A 60% TO 80% PROBABILITY OF RAINFALL AMOUNTS
TOPPING 0.25 INCHES, BUT THIS IS MAINLY IN THE NORTHWESTERN
PORTIONS OF THE FORECAST AREA. COVERAGE SHOULD BECOME MORE
SCATTERED BEHIND THE FRONT, BUT SHOWERS WILL PERSIST AS THE
UPPER TROUGH CONTINUES TO DEEPEN AND APPROACH FROM THE WEST.
SHORT TERM /SUNDAY NIGHT/
KEY MESSAGES:
- RAIN CHANCES INCREASE SUNDAY MORNING
- COLDER WITH RAIN MIXING WITH/CHANGING TO SNOW SUNDAY NIGHT
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OVERNIGHT AND INTO SUNDAY, A DEEPENING UPPER TROUGH IS PROGGED TO
DIG ACROSS THE UPPER MIDWEST AND WESTERN GREAT LAKES WHILE THE
SURFACE LOW (OVER SOUTHERN ILLINOIS) WILL DEEPEN AS IT TRACKS UP THE
OHIO RIVER VALLEY. RAIN CHANCES WILL SUBSTANTIALLY RAMP UP ACROSS
MUCH OF THE AREA SUNDAY MORNING AS THE SURFACE LOW TRAVERSES THE
EASTERN GREAT LAKES AND DRAGS A TRAILING COLD FRONT ACROSS THE
REGION TOMORROW AFTERNOON.
POST-FRONTAL PASSAGE, PRECIPITATION COVERAGE SHOULD BECOME MORE
SCATTERED, HOWEVER, SHOWERS WILL PERSIST AS THE UPPER TROUGH
CONTINUES TO DEEPEN AS IT APPROACHES THE REGION. TEMPERATURES DROP
QUICKLY SUNDAY NIGHT WHEN RAIN MIXES WITH AND THEN TRANSITIONS TO
SNOW. WITH WARM GROUND TEMPERATURES AND PRIOR TO THE SYSTEM MOVING
THROUGH, ONLY A FEW TENTHS OF AN INCH (MAINLY ON GRASS AND ELEVATED
SURFACES) ARE EXPECTED BY SUNRISE ON MONDAY.
LONG TERM /MONDAY THROUGH FRIDAY/
KEY MESSAGES:
- MUCH COLDER WITH SNOW SHOWERS MONDAY INTO TUESDAY
- ACCUMULATION POSSIBLE MAINLY NORTH OF I-80 AND IN THE RIDGES
- UNSETTLED WEDNESDAY AND THURSDAY WITH OCCASIONAL RAIN/SNOW
CHANCES MAINLY NORTH OF PITTSBURGH
- APPARENT TEMPERATURES IN THE TEENS TUESDAY MORNING
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THE UPPER-LEVEL TROUGH WILL CONTINUE TO MOVE ACROSS THE REGION ON
MONDAY. DIFFERENCES REMAIN IN THE UPPER PATTERNS BETWEEN THE GEFS
AND THE EURO WITH THE DURATION OF THE NW FLOW. DIFFERENCES IN THE
FLOW WOULD RESULT IN DIFFERING SNOW ACCUMULATIONS THROUGH TUESDAY.
DESPITE THESE DIFFERENCES, THE PICTURE REMAINS THE SAME THAT NW FLOW
WILL BRING SCATTERED TO NUMEROUS SNOW SHOWERS ACROSS PORTIONS OF THE
OH VALLEY.
850MB TEMPERATURES ARE EXPECTED TO DROP TO BETWEEN -8 TO -10 DEG C
BY MONDAY, WHILE LAKE ERIE TEMPERATURES HOVER AROUND +12 TO +14 DEG
C. LAKE AND TERRAIN ENHANCEMENT WILL BE LIKELY MONDAY NIGHT INTO
TUESDAY BEFORE FLOW BACKS TO THE W AND THE MOST EFFICIENT LAKE AND
TERRAIN ENHANCEMENT IS TURNED NORTH OF THE REGION. MESOSCALE
FEATURES (SUCH AS A REINFORCING SURFACE TROUGH) WILL GREATLY AFFECT
SFC TO 850MB FLOW AND THUS THE POSITIONING, DURATION, AND INTENSITY
OF ANY HEAVIER FOCUSED LAKE BANDS REMAINS LOW CONFIDENCE AT THIS
TIME. DESPITE THIS, MODELS CONTINUE TO HINT AT THE LIKELIHOOD OF ONE
OR SEVERAL LAKE BANDS YIELDING ENHANCED SNOWFALL NEAR AND SOUTH OF
LAKE ERIE. NBM PROBABILITIES FOR ADVISORY LEVEL SNOWFALL CONTINUE TO
FLUCTUATE. CURRENTLY, THERE IS A 40%-60% NORTH OF I-80 WHILE
THE PA AND WV RIDGES PROBABILITIES REMAIN BETWEEN 30%-40%. WE
WILL CONTINUE TO MONITOR THE EVOLUTION OF THIS SYSTEM AND
PATTERN OVER THE COMING FORECAST PERIODS.
THE SURFACE TROUGH IS WILL SHIFT TO THE NORTHEAST OF THE AREA ON
TUESDAY, AS BOUNDARY LAYER FLOW BACKS TO THE SW AND SNOW CHANCES
DECREASE THROUGH THE DAY. BROAD UPPER TROUGHING IS THEN EXPECTED TO
PERSIST ACROSS AREAS FROM THE UPPER MIDWEST INTO NEW ENGLAND.
OCCASIONAL RAIN/SNOW CHANCES WILL BE POSSIBLE, MAINLY NORTH OF PIT,
AS INDIVIDUAL SHORTWAVES ROTATE THROUGH THE TROUGH.
TEMPERATURES ARE EXPECTED TO BE 15 TO 20 DEGREES BELOW AVERAGE
MONDAY AND TUESDAY, BEFORE MODERATING SOME BY MID WEEK.
AVIATION /19Z SATURDAY THROUGH THURSDAY/
PASSING HIGH PRESSURE THIS AFTERNOON WILL ALLOW FOR SOME VFR
READINGS ACROSS THE AREA. ANOTHER SHORTWAVE TROUGH PASSING
THROUGH THE AREA TONIGHT WILL BRING SHOWERS AND SOME
DETERIORATING FLIGHT CONDITIONS OVERNIGHT, WITH JUST ABOUT EVERY
TERMINAL GOING BELOW IFR THROUGH 06Z TO THE END OF THE TAF
PERIOD. THERE MAY BE SOME IMPROVEMENT TO MVFR BY NOON TOMORROW
BUT OVERALL, EVERY TERMINAL WILL BE IMPACTED. WINDS WILL
SHIFT TO THE WEST LATE TONIGHT WITH SOME GUSTS REACHING 20 KNOTS
AT SOME OF THE TERMINALS.
OUTLOOK...
RESTRICTIONS ARE LIKELY TO CONTINUE SUNDAY NIGHT AS RAIN SHOWERS
CHANGE TO SNOW SHOWERS ALLOWING FOR LOWER CIGS EXPECTED. THIS
WILL PERSISTS THROUGH THE DAY ON MONDAY AS WELL WITH SOME
RESTRICTIONS POSSIBLE ON TUESDAY.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...SHALLENBERGER
NEAR TERM...SHALLENBERGER
SHORT TERM...88/LUPO
LONG TERM...LUPO/AK
AVIATION...SHALLENBERGER
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