956
FXUS61 KPBZ 061455
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1055 AM EDT SAT SEP 6 2025
SYNOPSIS
SHOWERS AND POSSIBLY A RUMBLE OF THUNDER WILL ACCOMPANY A WEAK
COLD FRONT OVERNIGHT AND INTO THE MORNING. DRY AND COOLER
TEMPERATURES EXPECTED SATURDAY AFTERNOON INTO SUNDAY.
NEAR TERM /THROUGH SUNDAY/
KEY MESSAGES:
- WAVES OF RAIN, MODERATE AT TIMES, ARE POSSIBLE TODAY BUT
FAVORING LOCATIONS SOUTH AND EAST OF PITTSBURGH
- HIGH TEMPERATURE WILL BE AROUND 10 DEGREES BELOW NORMAL
---------------------------------------------------------------
AN EMBEDDED MID-LEVEL SHORTWAVE ROUNDING THE EASTERN FLANK OF
THE BROAD UPPER LEVEL TROUGH WILL PROVIDE JET-INDUCED LIFT
THROUGH EARLY THIS MORNING TO PRODUCE AREAS OF SHOWERS AND
LOCALIZED THUNDERSTORMS. AVAILABLE SOUNDINGS SHOW LIMITED
BUOYANCY SHOULD PREVENT STORMS FROM DEVELOPING SEVERE WIND
DESPITE 40KTS OF EFFECTIVE SHEAR AND 40-50KTS OF SW WIND AT
700MB. AS THE WAVE TRANSLATES ENE THROUGH 10AM, EXPECT STORMS
CAPABLE OF LIGHTNING, GUSTY WIND UP TO 40 MPH, AND PERIODS OF
MODERATE RAIN WHILE GENERALLY STAYING EAST OF I-77 IN OHIO.
HI-RES MODELING INDICATES A PRECIPITATION LULL PERIOD DEVELOPING
AROUND 10AM IN BETWEEN SHORTWAVE MOVEMENTS BEFORE THE NEXT WAVE
INCREASES SHOWER ACTIVITY AFTER NOON. BY THIS TIME, THE PRIOR
WAVE WILL HAVE PUSHED THE SURFACE COLD FRONT SE THROUGH MOST OF
THE REGION; THIS MEANS BUOYANCY WILL BE NEIGH AVAILABLE AND
LIGHTNING POTENTIAL WILL BE LOW (LET ALONE ANY SEVERE THREAT).
AS THE UPPER TROUGH AXIS INCHES NEAR THE REGION LATE IN THE DAY,
THE PRECIPITATION LINE WILL SHIFT EAST OF THE AREA AS DRY
SLOTTING BEGINS TO ERODE CLOUDS WEST TO EAST. THOUGH LATE-DAY
SUNSHINE CAN'T BE RULED OUT, IT WILL BE TOO LITTLE, TOO LATE AS
AREA TEMPERATURE STRUGGLES TO REACH 70 DUE TO CLOUD COVER AND
SURFACE COLD ADVECTION.
DRY ADVECTION AND BUILDING SURFACE HIGH PRESSURE FAVORS MOSTLY
CLEAR OVERNIGHT SKIES THAT LEADS TO MORNING LOWS DIPPING INTO
THE 40S.
SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/
KEY MESSAGES:
- DRIER AND WARMER MONDAY INTO TUESDAY.
- PATCHY VALLEY FOG EACH MORNING.
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THERE IS HIGH CONFIDENCE IN HEIGHT RISES SUNDAY NIGHT INTO
MONDAY AS THE MAIN EASTERN TROUGH AXIS WEAKENS IN AMPLITUDE AND
MOVES OFF TO THE EAST, REPLACED BY A CENTRAL CONUS RIDGE AXIS
RIDING UP THE OHIO VALLEY. THIS WILL CLEAR SKIES OVERNIGHT
MONDAY ALLOWING EFFICIENT RADIATIVE COOLING TO TAKE LOWS AROUND
15 DEGREES BELOW AVERAGE WITH PATCHY VALLEY FOG. MONDAY, MIXING
WILL ALLOW WARMER (BUT STILL BELOW AVERAGE) AFTERNOON TEMPERATURES
MONDAY WITH ONLY PATCHY AFTERNOON CUMULUS WITH DRY CONDITIONS.
MONDAY NIGHT INTO TUESDAY WILL BRING MUCH OF THE SAME WITH COOL
LOWS AND VALLEY FOG, FOLLOWED BY ANOTHER DAY OF HEATING.
CORRESPONDINGLY, TEMPERATURES ARE FORECAST TO CLIMB A COUPLE
DEGREES COMPARED TO THE DAY PRIOR, BUT STILL REMAIN SLIGHTLY
BELOW AVERAGE. HIGH CLOUDS MAY INCREASE THROUGH TUESDAY AS UPPER
MOISTURE BLOWS OFF FROM A COASTAL SOUTHEAST LOW.
LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/
KEY MESSAGES:
- SEASONABLE TEMPERATURES AND DRY LATE-WEEK.
- FORECAST UNCERTAINTY GROWS NEXT WEEKEND.
-------------------------------------------------------------------
THERE APPEARS TO BE A CONTINUED CONSENSUS THAT UPPER SHORTWAVE
TROUGHING DROPS OVER THE AREA THROUGH THE WEDNESDAY TO FRIDAY
PERIOD, SLOWING THE WARMING TREND AND KEEPING TEMPERATURES NEAR
AVERAGE. DESPITE THE UPPER VEERING FLOW, NEAR-SURFACE HIGH
PRESSURE AND SUBSIDENCE IS FORECAST TO PREVAIL, KEEPING
TEMPERATURES NEAR CLIMATOLOGICAL NORMAL AND MUCH OF THE AREA
DRY.
ENSEMBLE UNCERTAINTY BEGINS TO SNOWBALL ON FRIDAY THROUGH NEXT
WEEKEND AS ENSEMBLES STRUGGLE WITH 1) JUST HOW LONG TO KEEP THE
WEAK EASTERN TROUGHING AROUND 2) THE AMPLITUDE AND EASTWARD
EXTENT OF A CENTRAL CONUS RIDGE, AND 3) THE LOWER-PROBABILITY
EVENT OF REINFORCED TROUGHING PATTERN DEVELOPING NEXT WEEKEND.
THE RANGE OF ALL SOLUTIONS WOULD HAVE TEMPERATURES ANYWHERE FROM
AROUND 10 DEGREES ABOVE AVERAGE TO 10 DEGREES BELOW AVERAGE. ON
THE WHOLE, ENSEMBLE MEANS HOLD TEMPERATURES STEADY, BUT TRENDS
ARE LIKELY TO FALL ON EITHER SIDE AS PATTERN RESOLUTION
CONTINUES. IN ALL SCENARIOS EXCEPT THE LOW- PROBABILITY OF A
STRONG UPPER TROUGH REINFORCEMENT, HOWEVER, RAINFALL WILL REMAIN
LIMITED TO NONE.
AVIATION /15Z SATURDAY THROUGH WEDNESDAY/
GENERALLY LIGHT RAIN AT 12Z WITH LOCALIZED CEILING RESTRICTIONS
WILL LARGELY PULL OUT OF THE REGION BY MID-MORNING, LEAVING
CLOUDY BUT GENERALLY VFR CONDITIONS. A SECOND WAVE OF LIGHT RAIN
IS FORECAST DURING THE MIDDAY/AFTERNOON HOURS, WHICH WILL
GENERALLY NOT BE VERY RESTRICTIVE EXCEPT PERHAPS TO BORDERLINE
MVFR VISIBILITY AT TIMES. MGW HAS THE BEST CHANCE OF SEEING
SIMILAR CATEGORIES WITH CEILING.
CLOUDS ARE EXPECTED TO BREAK FROM WEST TO EAST DURING THE
EVENING AND NIGHTTIME HOURS. VFR CONTINUES INITIALLY. ALTHOUGH
NOT DEPICTED IN CURRENT TAFS, A ROUND OF FOG IS POSSIBLE
TONIGHT, AT LEAST IN VALLEYS, BUT HREF DOES SHOW SOME POTENTIAL
FOR A MORE WIDESPREAD EVENT. THAT POSSIBILITY WILL BE EVALUATED
FOR FUTURE UPDATES.
OUTLOOK.
VFR IS LARGELY EXPECTED (OTHER THAN EARLY MORNING VLY FG)
THROUGH MID WEEK WITH HIGH PRESSURE IN CONTROL.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...FRAZIER
NEAR TERM...FRAZIER
SHORT TERM...MILCAREK
LONG TERM...MILCAREK
AVIATION...CL
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