274 FXUS61 KPBZ 091802 AFDPBZArea Forecast Discussion National Weather Service Pittsburgh PA 202 PM EDT Thu Oct 9 2025
.SYNOPSIS... High pressure provides dry and cool conditions into the upcoming weekend. The next chance of rain arrives this weekend, as weakening Great Lakes low pressure combines forces with a developing coastal storm system.
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.NEAR TERM /THROUGH TONIGHT/... KEY MESSAGES:
- Clear and quiet - Temperatures around 5 degrees below normal, with frost/freeze conditions ---------------------------------------------------------------
High pressure tracks to our north tonight across New York State and into western New England by morning. Diurnal cumulus have been few and far between this afternoon, given the overall dry column (0.25 precipitable water on the 12Z PBZ sounding). Afternoon highs are still on track to reach the upper 50s to lower 60s in the majority of cases.
This clear sky trend will continue tonight, although some localized steam fog may be possible again over the larger rivers. The main question centers around temperatures and the frost/freeze potential. The surface high track keeps a very modest surface pressure gradient over our region, with light easterly low-level flow tonight. While radiational cooling will not be ideal due to this, the dry air mass with dewpoints dropping into the upper 20s to mid 30s will still support conditions capable of producing frost/freeze conditions. Still, the Laurel Ridges in particular are tricky - the ridges are a bit more likely to hold on to wind overnight, and nearby valleys may experience a bit of a downslope effect from the easterly flow, if it remains strong enough.
Ended up going with a NBM mean/10th percentile temperature blend with a few tweaks, similar to previous shifts. This supports freezing or just below temperatures mainly to the north of Pittsburgh and in eastern Tucker County, and this is where the Freeze Warning has been placed. Frost Advisories were hoisted for other counties, save for portions of northern West Virginia and eastern Ohio. The aforementioned Laurels have a Frost Advisory for now, and cannot rule out the need for an upgrade here. The easterly flow/non-ideal radiational cooling does provide a hit to confidence.
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.SHORT TERM /FRIDAY THROUGH SATURDAY/... KEY MESSAGES:
- Slight warming trend and dry conditions through Saturday. - Increasing clouds Saturday afternoon. ----------------------------------------------------------------
The high will weaken as it moves eastward off the New England coast by Friday night with a ridge extending southwestward to eastern Kentucky. This will help to maintain mostly clear skies tomorrow. Wind is forecast to shift out of the southeast allowing for air to warm as result of downsloping along the ridges. Highs are forecast to reach into the mid to upper 60s, around average temperatures for this part of autumn. Light southeasterly wind will persist overnight inhibiting efficient radiative cooling, resulting in warmer overnight lows into the 40s.
The ridge will weaken as it moves eastward on Saturday. Most of the region expected to remain dry with highs in the upper 60s/lower 70s. Increasing clouds expected to the northwest moving into Saturday afternoon with an upper level trough approaching from the northwestern Great Lakes region.
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.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... KEY MESSAGES:
- Chance for measurable precipitation Saturday night into Sunday - Temperatures in the upper 60s and lower 70s - Drier pattern returns next week. -------------------------------------------------------------------
By Saturday night, an upper-level trough in the area will bring a chance for measurable precipitation Saturday night through Sunday night. There is a higher probability (>75%) for measurable precipitation for western Pennsylvania and northern West Virginia while a 55%-75% probability in eastern Ohio/northern West Virginia panhandle. High temperatures will slightly cool into the low to mid 60s on Sunday.
Models have been showing good continuity with this trough phasing with a coastal low off the Carolina coast on Sunday. There is a higher relative level of uncertainty in these scenarios mainly with the strength of the low/trough. Guidance shows relatively good agreement in ridging building back in over the eastern CONUS, however, there is uncertainty with the strength of the ridge as the trough moves offshore.
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.AVIATION /18Z THURSDAY THROUGH TUESDAY/... VFR conditions are forecast for the next 24 hours with high pressure tracking north of the region. Isolated diurnal cumulus will collapse with sunset, with a clear overnight and perhaps a few high clouds by midday Friday. Steam fog may occur once again on the larger rivers given expected cool air temperatures, but any terminal impact should be brief at best. Light east wind through tonight will veer towards the southeast Friday morning.
.OUTLOOK... VFR is expected through Saturday under high pressure. Restriction and shower potential returns Saturday night through early Monday as an upper level low tracks southeast across the region.
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.PBZ WATCHES/WARNINGS/ADVISORIES... PA...Frost Advisory from midnight tonight to 9 AM EDT Friday for PAZ020-021-029-031-073>076-078. Freeze Warning from midnight tonight to 9 AM EDT Friday for PAZ007>009-013>016-022-077. OH...Frost Advisory from midnight tonight to 9 AM EDT Friday for OHZ039>041-048>050-057-058. WV...Frost Advisory from midnight tonight to 9 AM EDT Friday for WVZ001-002-510>513. Freeze Warning from midnight tonight to 9 AM EDT Friday for WVZ514.
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SYNOPSIS...CL NEAR TERM...CL SHORT TERM...Lupo LONG TERM...Lupo AVIATION...CL
NWS PBZ Office Area Forecast Discussion