Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
245 FXUS61 KPBZ 030238 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 938 PM EST Tue Dec 2 2025 .SYNOPSIS... Drier weather expected tonight through Wednesday, followed by additional snow chances and below-normal temperatures through the end of the week. && .NEAR TERM /UNTIL 8 AM WEDNESDAY MORNING/... KEY MESSAGES: - Refreezing on untreated surfaces could cause slick spots and hazardous travel overnight into Wednesday morning. --------------------------------------------------------------- Any moisture that has remained (especially on untreated roads and sidewalks) has frozen with temperatures already below freezing. This will lead to slick spots and hazardous travel conditions tonight and Wednesday morning. Overnight, temperatures will continue to drop into the mid to lower 20s with overcast skies. && .SHORT TERM /8 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... KEY MESSAGES: - Dry weather and below-seasonal temperatures Wednesday - A front Wednesday night into Thursday provides a reinforcing cold shot and some minor snow accumulation mainly in the ridges and north of I-80 - Very cold temperatures Thursday night; single digits possible north of Pittsburgh ---------------------------------------------------------------- Surface high pressure crosses the Middle Ohio Valley and the Central Appalachians later Tuesday night and Wednesday, and extends ridging up into the forecast area. This should provide dry weather and continued chilly temperatures. Highs on Wednesday will continue to run some 10 to 12 degrees below climatology. The next cold front, extending from low pressure over Hudson Bay, is forecast to cross the region late Wednesday night and Thursday morning. The associated shortwave trough is expected to remain mostly over the northern Great Lakes, keeping much of the synoptic support to our north. Still, the boundary will provide a reinforcing shot of cold air as 850mb temperatures drop into the -10C to -15C range by Thursday afternoon. Given the system`s northern origins, moisture remains limited overall. A shot of light snow is forecast, with minor accumulation. Parts of western PA south of I-80 and northern WV have a 30 to 50 percent chance of exceeding a half inch (but a 20 percent chance or less at exceeding an inch). Probabilities are locally higher in the Laurels, owing to stronger lift with upslope enhancement, where there is a 50 to 70 percent chance of exceeding a half inch and a 30 to 40 percent chance of exceeding an inch. Additionally portions of Mercer and Venango may be more favored for lake- enhanced activity as model soundings hint at some modest instability and reasonably steep lapse rates into the DGZ that could support briefly stouter snow showers during peak heating. Better potential for such activity, including snow squalls, lies to the north with deeper moisture and instability, but those areas north of I-80 could still see an inch or so of accumulation before snow ends Thursday afternoon. High pressure then builds into the region following Thursday`s cold front, with temperatures Thursday night looking to be the coldest of the week. The latest NBM suggests a70 percent chance or greater of lows dropping below 20 degrees across the entire county warning area. It also suggests a 40 to 60 percent chance for single digits along and north of the I-80 corridor (20 to 40 percent chance in areas farther south). && .LONG TERM /FRIDAY THROUGH TUESDAY/... KEY MESSAGES: - Dry and cold Thursday night and Friday - Below average temperatures and continued wintry precipitation chances into early next week ------------------------------------------------------------------- Analysis of ensemble model clustering continues to favor broad upper level troughing east of the Rockies Friday with an embedded shortwave lifting fairly quickly through the Ohio River Valley. These trends favor keeping the surface low track south of the region, with only low probability for light snow clipping locations south and east of Pittsburgh through the day. Passage of the upper trough axis and surface cold front Saturday/Saturday night may provide enough cold advection within NW flow plus weak lift to create lower probability precipitation chances that favor higher terrain and Lake Erie- adjacent zones. Temperature is highly favored to stay below average as the Saturday front only reinforces the recent seasonably cool trends. Eastern CONUS trough is likely to persist into early next week with embedded shortwave movement driving precipitation chances. Periodic but generally light precipitation chances could develop while the cooler airmass generally maintains a snow precipitation type. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... KEY MESSAGES: -MVFR prevails through the first half of Wednesday -Scattering to VFR expected in the afternoon -Gradual wind shift from NW to SW ------------------------------------------------------------------- Conditions have improved to MVFR across the board this evening with the departure of snow. A lingering upper trough and NW flow off of the Great Lakes is maintaining a few flurries, but no observations have shown notable degradation in restrictions from the overall broad 1.5-2.5 kft cigs. MVFR conditions will prevail tonight and through tomorrow morning as low level moisture remains in place beneath a sinking subsidence inversion from approaching high pressure. Said high pressure will briefly build in Wednesday with wind backing to the SW around 8-10 knots. Improvement to VFR is expected by afternoon as drier low level air advects in, though mid-level moisture and associated cloud coverage will concurrently increase ahead of the next approaching cold front expected on Thursday. Outlook... Cig restrictions are likely, along with scattered snow showers, late Wednesday night into Thursday with a crossing cold front. VFR is expected to return late Thursday and Friday as high pressure builds in behind the front. Restrictions are possible again Saturday and Sunday with a crossing cold front. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...Cermak/CL NEAR TERM...Cermak/Lupo SHORT TERM...Cermak/CL LONG TERM...Frazier AVIATION...WM/MLB