040
FXUS61 KPBZ 061736
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
136 PM EDT SAT SEP 6 2025
SYNOPSIS
ANOTHER ROUND OF LIGHT RAIN IS EXPECTED INTO THE AFTERNOON,
ESPECIALLY SOUTH AND EAST OF PITTSBURGH. A MOSTLY DRY PATTERN
WILL THEN TAKE HOLD STARTING TONIGHT. COOL TEMPERATURES THROUGH
SUNDAY WILL BE FOLLOWED BY A SLOW WARMING TREND DURING THE WORK
WEEK.
NEAR TERM /THROUGH SUNDAY/
KEY MESSAGES:
- ADDITIONAL LIGHT RAIN THIS AFTERNOON, ESPECIALLY FROM
PITTSBURGH AND TO THE SOUTHEAST
- DRIER WEATHER TONIGHT AND SUNDAY, SAVE FOR A FEW SHOWERS NORTH
OF I-80 SUNDAY
- TEMPERATURES ABOUT 10 DEGREES BELOW NORMAL THROUGH SUNDAY
---------------------------------------------------------------
THE LATE-MORNING RELATIVE LULL IN RAINFALL IS BEGINNING TO END.
AS AN UPPER JET MAX ROTATES AROUND THE EASTERN PORTION OF A
LARGE-SCALE UPPER TROUGH, RIGHT-REAR QUADRANT JET DYNAMICS IS
SUPPORTING AN AREA OF LIGHT RAIN OVER THE OHIO VALLEY THAT WILL
CONTINUE TO LIFT INTO OUR REGION WITH TIME INTO THE EARLY
AFTERNOON. WITH LIFT WEAK OVERALL, NO INSTABILITY TO SPEAK OF,
AND SLOWLY DECREASING PRECIPITABLE WATER BEHIND THE EARLIER COLD
FRONT, RAIN WILL CONTINUE TO BE LIGHT. ABOUT 0.10" INCH OR LESS
OF ADDITIONAL RAIN IS FORECAST, MOST OF WHICH WILL FALL OVER
THE SOUTHEASTERN HALF OF THE CWA. DAYTIME HIGHS ARE STILL
EXPECTED TO END UP SOME 10 DEGREES BELOW NORMAL.
THE RAIN WILL ERODE THROUGH THE AFTERNOON AS SUPPORT FOR LIFT
DECREASES WITH THE DEPARTING JET MAX, WITH ONLY THE SOUTHEAST
RIDGES HANGING ON TO A FEW SHOWERS BY SUNSET. THE ADVECTION OF A
DRIER AIRMASS AND APPROACHING HIGH PRESSURE WILL HELP TO ERODE
CLOUDS FROM WEST TO EAST THIS EVENING, WITH A MOSTLY CLEAR
OVERNIGHT PERIOD FORECAST. SOME PATCHES OF FOG MAY DEVELOP,
ESPECIALLY IN RIVER VALLEYS TO THE SOUTH AND EAST OF
PITTSBURGH. COOL OVERNIGHT LOWS IN THE 40S TO AROUND 50 ARE MOST
LIKELY.
SUNDAY WILL FEATURE DRY WEATHER FOR MOST, WITH LOW-LEVEL RIDGING
TAKING CONTROL OVER THE UPPER OHIO VALLEY. MODEL SOUNDINGS
INDICATE ENOUGH MODEST, SHALLOW INSTABILITY FOR DIURNAL CUMULUS
DEVELOPMENT. WITH 850 TEMPS OF 3-4C ADVECTING OVER LAKE ERIE
WATER TEMPS OF 22C OR SO, A FEW LAKE-EFFECT RAIN SHOWERS WILL BE
POSSIBLE NORTH OF I-80 DURING THE DAY. TEMPERATURES WILL BE
FAIRLY SIMILAR TO TODAY, AS INCREASED SUNSHINE IS OFFSET BY THE
COOLER 850MB TEMPERATURES.
SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/
KEY MESSAGES:
- DRIER AND WARMER MONDAY INTO TUESDAY
- PATCHY VALLEY FOG EACH MORNING
--------------------------------------------------------------
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 /18Z SATURDAY THROUGH THURSDAY/
AN AREA OF LIGHT RAIN THIS AFTERNOON, SUPPORTED BY UPPER
DIVERGENCE IN THE RIGHT ENTRANCE REGION OF AN UPPER JET, WILL
REMAIN GENERALLY SOUTH AND EAST OF A ZZV/PIT/DUJ LINE, WITH
MINIMAL VISIBILITY RESTRICTION FOR THE MOST PART. PERHAPS A
BRIEF DROP TO HIGH-END MVFR WILL BE POSSIBLE AT MGW, LBE, OR
DUJ, BUT MOST OF THE PERIOD WILL REMAIN VFR.
CLOUDS BREAK TONIGHT, WITH CONTINUED VFR IN MOST CASES. SOME
FOG, MAINLY IN VALLEYS, IS EXPECTED LATE TONIGHT/EARLY SUNDAY
MORNING. MGW, LBE, AND DUJ HAVE THE BEST SHOT AT A PERIOD OF
MVFR/IFR VISIBILITY ACCORDING TO HREF PROBABILITIES, AND HAVE
INCLUDED MENTION IN THOSE TAFS.
ANY FOG WILL LIFT BY 13Z OR SO SUNDAY, WITH VFR FOR THE BALANCE
OF THE DAY. AFTERNOON CUMULUS AND SOME NORTHWEST WIND GUSTS TO
AROUND 15 KNOTS WILL BE POSSIBLE BEGINNING AROUND MIDDAY.
OUTLOOK.
VFR IS LARGELY EXPECTED (OTHER THAN EARLY MORNING VALLEY FOG)
THROUGH MID WEEK WITH HIGH PRESSURE IN CONTROL.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...CL
NEAR TERM...CL
SHORT TERM...MILCAREK
LONG TERM...MILCAREK
AVIATION...CL
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