367
FXUS61 KPBZ 210925
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
425 AM EST WED JAN 21 2026
WHAT HAS CHANGED
BETTER CONFIDENCE IN A PROLONGED COLD EVENT FRIDAY THROUGH THE
WEEKEND. POTENTIAL FOR ISOLATED FREEZING DRIZZLE EARLY THURSDAY.
POTENTIAL WEEKEND WINTER STORM TRACK HAS TRENDED WESTWARD.
KEY MESSAGES
1) RAIN AND SNOW RETURN TODAY AND THURSDAY WITH A PASSING
TROUGH AND ASSOCIATED FRONT. A WINTER WEATHER ADVISORY REMAINS
IN EFFECT FOR NORTHERN COUNTIES
2) SNOW POSSIBLE AGAIN SATURDAY INTO SUNDAY. TOTALS DEPENDENT
ON THE WESTERN EXTENT OF THE LOW PRESSURE TRACK
3) CONSECUTIVE COLD MEAN DAILY TEMPERATURES STARTING FRIDAY
THROUGH THE FIRST HALF OF NEXT WEEK COULD NEGATIVELY IMPACT
REGIONAL INFRASTRUCTURE, SUCH AS FROZEN PIPES, AND PUTTING A
STRAIN ON THE ENERGY GRID.
DISCUSSION
KEY MESSAGE 1... RAIN AND SNOW RETURN TODAY AND THURSDAY WITH A
PASSING TROUGH AND ASSOCIATED FRONTAL SYSTEM. A WINTER WEATHER
ADVISORY REMAINS IN EFFECT FOR NORTHERN COUNTIES
A TROUGH AND ASSOCIATED FRONT CROSSING THE REGION TODAY WILL
BRING ANOTHER ROUND OF SNOW AND A RAIN/SNOW MIX TO THE AREA.
INITIALLY PRECIPITATION SHOULD BE ALL SNOW, BUT TRANSITION TO A
RAIN SNOW MIX FROM SOUTH TO NORTH UP AS FAR NORTH AS PA SR422
DURING THE AFTERNOON WITH WARM ADVECTION AHEAD OF THE FRONT. 2
TO 5 INCHES OF SNOW WILL BE POSSIBLE ACROSS NORTHERN COUNTIES
(HIGHER VALUES FROM SOUTH TO NORTH), MAINLY ALONG AND NORTH OF
I-80. GUIDANCE HAS SHOWN REASONABLY GOOD CONTINUITY WITH AMOUNTS
AND LITTLE CHANGE WAS MADE TO OVERALL SNOW TOTALS. LATEST
ENSEMBLES SHOW A 40-75% CHANCE OF >3" WITHIN THE CURRENT
ADVISORY AREA, SO THE ADVISORY HAS BEEN MAINTAINED.
ADDITIONALLY, THERE LOOKS TO BE A CHANCE FOR FREEZING
RAIN/DRIZZLE FARTHER NORTH WHERE IT WAS PREVIOUSLY ALL SNOW
LATER THIS AFTERNOON AND EVENING BASED OFF LATEST FORECAST
SOUNDINGS, WHICH SHOW ALL OF THE MOISTURE AND LIFT BELOW -10C
FOR AT LEAST SEVERAL HOURS. NBM UNCONDITIONAL PROBABILITIES FOR
FREEZING RAIN BUMP UP TO AROUND 20% FROM 20Z-01Z, AND THE HREF
ALSO HINTS A A GLAZE IN SPOTS NORTH OF SR 422 AS WELL DURING
THIS TIMEFRAME. HAVE ADDED MENTION OF THIS IN THE LATEST
ADVISORY UPDATE. THE RIDGES IN PA AND WV COULD ALSO SEE FREEZING
RAIN/FREEZING DRIZZLE LATER THIS AFTERNOON AND EVENING, BUT
PROBABILITIES ARE TOO LOW FOR ANY HEADLINES AT THIS TIME, BUT
IT WILL NEED TO BE WATCHED.
ANOTHER CONSIDERATION IS FOR AREAS THAT SEE RAIN DURING THE DAY
ON WEDNESDAY WHERE SURFACE TEMPERATURES MAY STILL BE BELOW
FREEZING GIVEN PREVIOUS COLD TEMPERATURES. THIS WILL NEED TO BE
MONITORED STILL.
KEY MESSAGE 2... SNOW POSSIBLE SATURDAY INTO SUNDAY. TOTALS
DEPENDENT ON THE WESTERN EXTENT OF THE LOW PRESSURE TRACK.
THIS WEEKEND THERE IS A LOW PRESSURE SYSTEM FORECAST TO DEVELOP TO
THE SOUTH AND MOVE EAST OF THE AREA. THERE ARE DIFFERENT OUTCOMES
RESULTING FROM THE UNCERTAINTY IN THE STORM TRACK.
(1) THE FIRST OUTCOME WOULD BE THE LOW DEVELOPING AND STAYING TO THE
SOUTH, MAINLY TRACKING THROUGH THE SOUTHEASTERN U.S. THIS WOULD
RESULT IN LOW SNOW ACCUMULATIONS (<1") FOR OUR REGION WHICH HAS A
20% CHANCE OF OCCURING.
(2) THE SECOND OUTCOME WOULD BE THE LOW STAYING SOUTH BEFORE CURVING
NORTHWARD AS IT APPROACHES THE MID-ATLANTIC REGION. THERE WOULD BE
MEASURABLE SNOW ACCUMULATION FOR THE REGION WITH A LIKELY RANGE
BETWEEN 1" IN THE NORTH TO 6" IN PARTS OF NORTHERN WEST VIRGINIA.
CURRENTLY, THIS APPEARS TO BE THE MOST LIKELY OUTCOME WITH A 50%
CHANCE OF OCCURRENCE.
(3) THE THIRD OUTCOME WOULD BE THE LOW CURVING NORTHWARD SOONER AND
TRACKING ALONG THE APPALACHIAN MOUNTAIN RIDGES BEFORE REFORMING
OFFSHORE IN THE ATLANTIC. THIS WOULD RESULT IN THE HIGHEST POSSIBLE
ACCUMULATION WITH >6" LIKELY AND A POSSIBLE MAXIMUM ACCUMULATION OF
UP TO 12" (IN NORTHERN WV). THIS IS THE LEAST LIKELY OUTCOME WITH A
20% CHANCE OF OCCURRENCE.
WE WILL CONTINUE TO MONITOR THIS STORM THROUGHOUT THE WEEK AND
PROVIDE UPDATES ALONG THE WAY.
KEY MESSAGE 3... CONSECUTIVE COLD MEAN DAILY TEMPERATURES STARTING
FRIDAY THROUGH THE FIRST HAVE OF NEXT WEEK COULD NEGATIVELY IMPACT
REGIONAL INFRASTRUCTURE, SUCH AS FROZEN PIPES, AND PUTTING A STRAIN
ON THE ENERGY GRID.
MODEL GUIDANCE CONTINUES TO SIGNAL A RELATIVELY LONG PERIOD OF WELL
BELOW NORMAL TEMPERATURES FROM FRIDAY INTO LATE NEXT WEEK. EMPIRICAL
DATA SUGGESTS INFRASTRUCTURE PROBLEMS (FROZEN PIPES, ETC), START TO
OCCUR AFTER THE MEAN DAILY TEMPERATURE RUNS -12F BELOW NORMAL FOR 48
HOURS OR MORE. FOR THIS TIME OF YEAR IN THE PGH AREA THIS IS
APPROXIMATELY A DAILY MEAN TEMPERATURE OF 15F.
THROUGH TUESDAY, HIGHS IN THE UPPER TEENS/LOW 20S AND LOWS NO HIGHER
THAN 10F ARE LIKELY FOR A MAJORITY OF THE AREA. THIS WOULD RESULT IN
THE DAILY MEAN TEMPERATURE REMAINING BELOW 15F . THERE IS INCREASED
UNCERTAINTY LATER INTO NEXT WEEK. A LOT CAN CHANGE BEING THAT FAR
OUT, BUT IT WILL BE MONITORED.
ADDITIONALLY, WE MAY SEE RELATIVELY FAST ICE FORMATION ON AREA
RIVERS GIVEN THE AVERAGE DAILY TEMPERATURES THAT ARE FORECAST.
AVIATION /09Z WEDNESDAY THROUGH SUNDAY/
KEY MESSAGES...
1) VFR THROUGH MOST OF THE MORNING.
2) MVFR/IFR CIG/VIS RESTRICTIONS WITH SNOW AFTER 18Z.
3) TIGHTENING PRESSURE GRADIENT BRINGS GUSTY SOUTH/SOUTHWEST
WINDS.
------------------------------------------------------------
HIGH PRESSURE WILL KEEP THE AREA DRY WITH LIGHT WINDS THROUGH
OVERNIGHT HOURS. HIGH CLOUDS BEGIN TO MOVE IN AND CEILINGS
GRADUALLY LOWER THROUGH THE MORNING AHEAD OF THE NEXT
APPROACHING LOW PRESSURE SYSTEM. SNOW CHANCES INCREASE BY LATE
MORNING AND AFTERNOON ACROSS MUCH OF THE AREA AS CEILINGS DROP
TO MVFR/IFR. RAIN MAY MIX IN AT TIMES, PRIMARILY ALONG AND SOUTH
OF I-70. VISIBILITIES MAY DROP AS LOW AS IFR/LIFR INSIDE
PRECIPITATION, ESPECIALLY DURING INSTANCES OF HEAVIER SNOW.
SOUTH-SOUTHWEST WINDS INCREASE AFTER SUNRISE, WITH GUSTS IN THE
20-25 KNOT RANGE. GUSTY WINDS WILL LINGER THROUGH THE REMAINDER
OF THE PERIOD.
OUTLOOK... RESTRICTIONS AND SNOW LINGER INTO THURSDAY WITH THE
APPROACH AND PASSAGE OF A COLD FRONT. CIG RESTRICTIONS ARE STILL
POSSIBLE FRIDAY AND SATURDAY UNDER COLD NW FLOW AND BROAD UPPER
TROUGHING.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 10 AM EST
THURSDAY FOR PAZ007>009-015-016-077-078.
OH...NONE.
WV...NONE.
DISCUSSION...88
AVIATION...CERMAK/RACKLEY
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page