401 FXUS61 KPBZ 042323 AFDPBZArea Forecast Discussion National Weather Service Pittsburgh PA 723 PM EDT Sat Oct 4 2025
.SYNOPSIS... High pressure remains dominant through Monday, leading to continued dry weather and warm temperatures. The next chance of a wetting rainfall arrives Tuesday into Wednesday.
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.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... KEY MESSAGES:
- Dry weather continues under high pressure. - Lows remain just above normal, patchy valley fog possible. -------------------------------------------------------------
Expansive upper ridging over the eastern CONUS and surface high pressure just off of the Mid-Atlantic coast will maintain mostly clear skies through tonight, save for occasional patches of thin cirrus. Some patchy valley fog is once again expected around sunrise Sunday given nearly calm wind, a clear sky, and an overall dry airmass.
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.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/... KEY MESSAGES:
- Dry and warm Sunday and Monday ----------------------------------------------------------------
Sunday will be another beautiful day and very similar to Saturday. Upper ridging slowly pivots eastward and high pressure remains anchored off the New England coast with light southerly flow promoting another warm day with low 80s highs. Dew points remain comfortable with dry boundary layer mixing.
On Monday, a weak shortwave will move through in southwest flow on the back periphery of the eastward moving ridge. This should result in an increase in cloud cover by the latter half of the day, but plenty of dry air precludes any precipitation mention. Continued light southerly flow will modify the airmass a touch more with afternoon highs a tick higher than Sunday. Cloud coverage will continue to increase overnight Monday night ahead of an approaching cold front.
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.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... KEY MESSAGES:
- Passing cold front returns areawide rain Tuesday - Dry weather returns Wednesday with some gusty wind - Temperatures fall to seasonal normals -------------------------------------------------------------------
Low pressure passing way off to our north will drag a cold front through the area on Tuesday and return high rain chances areawide. Flow will increase out of the south just a bit ahead of the boundary and return 60s dew points. PWATs will bump up to near 1.5" which is around the 90th percentile of climatology, so plenty of moisture will be available to work with. The best shortwave energy and dynamics will remain displaced to our north, even in ensemble members that favor a deeper trough. Timing of this feature shows little disagreement, so feel pretty confident that rain will arrive on Tuesday morning with the highest coverage in the afternoon and evening hours coincident with strongest forcing from the boundary. Instability looks like it`ll be hard to come by with a very saturated profile and even the 25th percentile cloud coverage from NBM >50% Tuesday morning and increasing through the day. Still, while not a drought buster, this should be a welcomed wetting rain for most. Probability for >0.25" is around 80-90%, >0.5" at 60-80%, and >1" at 20-40%, so the most likely range as of now 0.25"-0.75" with some locally higher amounts possible.
The trough quickly kicks out of here early Wednesday as the front does the same. A slower, less likely solution suggests some showers could linger into the late morning hours, but the general consensus among most of the ensembles is for a quicker departure. High pressure builds in immediately on its heels as dry air arrives in north-northwest flow. It`ll likely be a bit gusty in the wake of the front with a tightening gradient ahead of the building high, and NBM max gust probabilities show a 40-60% chance of >25 mph gusts for most of eastern OH/western PA.
The other notable difference will be temperatures starting to feel more like fall. Normal high temperatures are in the mid 60s and that`s right around where we look to be to close out the latter half of the week with dry weather returning. Another disturbance may return rain chances headed into next weekend but details remain fuzzy at this point.
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.AVIATION /00Z SUNDAY THROUGH THURSDAY/... High confidence VFR continues through the TAF period under high pressure. Mostly clear skies and light (generally southerly) winds are expected overnight and into the day tomorrow. Model probabilities are very low on any valley fog but ambient conditions suggest formation is still possible, even if impacts are more doubtful.
.OUTLOOK.... VFR conditions are expected on the whole through Monday as high pressure remains in control. Patchy valley fog is once again possible Monday morning, but with minimal terminal impact. Restrictions are forecast to return Tuesday into Wednesday as an approaching front brings rain chances.
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.PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None.
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SYNOPSIS...CL NEAR TERM...CL/Milcarek SHORT TERM...MLB LONG TERM...MLB AVIATION...AK
NWS PBZ Office Area Forecast Discussion