121 FXUS61 KPBZ 140545 AFDPBZArea Forecast Discussion National Weather Service Pittsburgh PA 145 AM EDT Sun Sep 14 2025
.SYNOPSIS... Dry and warm weather is expected through much of the week under high pressure.
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.NEAR TERM /THROUGH TODAY/... KEY MESSAGES:
- Dry and warm today ---------------------------------------------------------------
Early morning cloud cover will continue to clear from north to south as a weak upper level trough completes its passage across the Upper Ohio Valley region. Patchy early morning river valley steam fog is also expected as the clearing occurs.
Otherwise, surface high pressure will remain centered to our north across Ontario today. 500 mb heights will also rise through the day as a strong ridge across the central CONUS begins to drift eastward. Mostly sunny skies are expected today, with just a few diurnal cumulus clouds possible as convective temperatures are reached. Lowered dew points a few degrees below NBM guidance with mixing down of dry air today. High temperatures are expected to be around 10 degrees above average.
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.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... KEY MESSAGES:
- Dry and warm weather continues through Tuesday - Low shower chances return for the ridges Tuesday night --------------------------------------------------------------
Surface high pressure will strengthen as it drifts across eastern Canada and the NE CONUS. At the same time, the strong ridge across the central CONUS will continue to build eastward through Tuesday. This pattern should maintain dry and warm weather through early in the week.
A coastal low is expected to begin moving northward across the Carolinas Tuesday night, as high pressure remains centered across the NE CONUS. The upper ridge is also progged to weaken as the low approaches. Some increase in cloud cover is expected ahead of the approaching low. Moisture rotating around the low could spread a few showers as far west as the ridges of PA and WV Tuesday night, though rain chances are expected to remain limited with a dry easterly flow.
High temperatures are expected to remain above average, with Monday being the warmest day of the period. Highs Tuesday could be a couple of degrees lower than Monday, as 500mb heights begin to fall ahead of the approaching low. Overnight lows will still be close to, or a few degrees above average, with efficient night time radiational cooling.
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.LONG TERM /WEDNESDAY THROUGH SATURDAY/... KEY MESSAGES:
- Above average temperatures continue - Dry for most of the area through late week - Low rain chances return Saturday ------------------------------------------------------------------
Model ensembles indicate low pressure is expected to track slowly northward along the Mid Atlantic coast on Wednesday. Minimal precip chances are expected near the PA and WV ridges, through a dry, downsloping easterly flow should preclude precip across the remainder of the area, though some increase in cloud cover is expected.
Ridging is then progged to build across the Ohio Valley region behind the exiting low through the day on Thursday. The ridge is then progged to track slowly eastward across the Upper Ohio Valley region through Friday, maintaining dry weather. Temperatures are expected to be a few degrees above average on Wednesday, reaching levels around 10 degrees above average by late week as 500mb heights rise.
Ensembles indicate a trough across the Midwest will advance slowly eastward toward the weekend. At this time, minimal rain chances are in the forecast as this trough approaches, through uncertainty exists in the strength of the trough, and the amount of moisture available.
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.AVIATION /06Z SUNDAY THROUGH THURSDAY/... Expect VFR conditions throughout the TAF period, with the exception of a brief period of river valley fog near FKL between 09Z to 12Z this morning. High to mid-level clouds will persist south of PIT for the next 3-4 hours before drier air moves in from the north, as observed on GOES-19 water vapor satellite imagery.
Diurnal driven cu appears favorable south and east of Pittsburgh, mostly along the ridges, after 15Z. Fair weather cu will dissolve after dark with decoupling.
.OUTLOOK.... Early morning river valley fog potential continues Monday morning. Otherwise, high confidence of VFR under high pressure with winds be light and variable from the north/northeast.
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.PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None.
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SYNOPSIS...WM NEAR TERM...WM SHORT TERM...WM LONG TERM...WM AVIATION...Hefferan
NWS PBZ Office Area Forecast Discussion