Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
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482 FXUS61 KPBZ 052318 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 618 PM EST Fri Dec 5 2025 .SYNOPSIS... Periodic light snow chances and below-normal temperatures continue through the weekend. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... KEY MESSAGES: - Flurries/freezing drizzle possible at higher terrain, however, precipitation chances decreasing overnight. - Overcast skies with low temperatures about 10 degrees warmer than Friday morning. --------------------------------------------------------------- A weak shortwave embedded in the flow will continue to pass to the south, allowing for some weak column lift, particularly when combined with a subtle inflection point in the upper jet. This has allowed some flurries to occur well into the forecast area with the only chance of any light accumulations in the high terrain (50% to 60% chance of any accumulation). In these areas, there is also the possibility for some freezing drizzle which will be spotty. The chance for precipitation will decrease overnight. Cloud cover is expected to fill-in overnight, making radiative cooling far less efficient. In addition, the sfc-850mb will be much warmer than the night prior, keeping forecast lows ~10 degrees warmer than Friday morning. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... KEY MESSAGES: - Below normal temperatures continue - Additional waves of light wintry precip over the weekend - Only minor accumulations expected, primarily north of I-80 and in the ridges ---------------------------------------------------------------- A series of weak mid-level shortwaves traverse the Great Lakes and Ohio Valley over the weekend. The first brings low chances for light snow showers to areas generally near and north of Pittsburgh on Saturday, with little or no accumulations expected. This is further confirmed in the NBM with the probabilities roughly below 20% for the southern/low elevation areas receiving even a tenth. The second wave is slightly stronger than the first and brings higher chances for a wintry mix to the entire area on Sunday. Precipitation is expected to start at snow (possibly a rain/snow mix in the Mon Valley) Sunday morning before transitioning to a rain/snow mix across the lowlands south of I-80 by late morning and afternoon. Overall accumulations with the Sunday system are still anticipated to be light, with measurable snowfall appearing most likely north of I-80 and in the ridges. The latest NBM probabilities in those areas suggest a 20-40% chance of exceeding an inch, 10-20% chance for 2 inches, and a nil chance for 3 inches. This leaves locations such as Pittsburgh a 40% to 60% chance for just a 20% to 30% chance for even a half inch. A cold front brings a reinforcing shot of cold air and northwest flow late in the day Sunday into Sunday night, will slowly bring an end to the precipitation just about everywhere by Monday morning. The ridges will likely keep the flurry activity going through dawn on Monday morning but will still come to an end rather quickly. Highs on Saturday and Sunday reach the mid to upper 30s for much of the area. Lows Saturday night continue a slight warming trend and remain in the mid to upper 20s, while lows Sunday night drop back into the teens and low 20s under post-frontal northwest flow and cold advection. Keep in mind that these temperatures are still below normal. && .LONG TERM /MONDAY THROUGH FRIDAY/... KEY MESSAGES: - Below normal temperatures continue the middle of next week. - Another round of winter weather potential towards mid week. ------------------------------------------------------------------- Dry post-frontal flow and building surface high pressure keep the area dry and cold to start next week. The mentioned high will keep any precip from lifting north into the forecast area, as a low pressure system is expected to pass to the south. While Tucker and Preston counties could see some light snow on Monday, the amounts will be less than an inch with the rest of the forecast area remaining dry. In fact the NBM probs give a less than 10% for even a inch of snowfall. The Tuesday and into Wednesday disturbance will feature a strong and progressive low pressure system track in from the northwest as the trough over the east continues to filter into the region colder air and precip chances. However, given some warm advection in from the south on Wednesday, there will likely be a change over to rainfall. There also stands the chance for some freezing precip to mix in at times. The Tuesday and Wednesday shortwave will be one to watch as well as the long term period features an active pattern. This in conjunction with the overall colder than normal temperatures expected, can expect the potential for snow in the extended. Colder air will filter in behind the front on Thursday. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... Staunch MVFR to occasionally IFR stratus covering the southeast 2/3rds of the forecast area appears more and more likely to remain in place through the overnight period. HREF model data supports this thought with 70-90% probabilities for MVFR or lower ceilings to exist at most terminals, with some hint at NW expansion with weak southerly flow. There remains a non-zero chance for this region to experience enough lift for localized light snow or (if ice crystals don`t form) freezing drizzle. Will preclude TAF mention of that at this time, but it will bear monitoring. For areas outside of the stratus deck (BVI/FKL), light wind and radiational cooling may favor IFR/LIFR freezing fog development that is likely to wane if/when the stratus cloud deck reaches the terminal. Increased mixing/lift Saturday morning ahead of an incoming shortwave should result in some improvements to overnight restrictions (less likely at FKL/DUJ where warm frontal convergence occurs). However, any VFR conditions are likely to be short-lived as the afternoon passage of the shortwave of surface front re-introduce an MVFR stratocu deck and lower probability light snow showers (FKL/DUJ having greatest likelihood for visibility impacts due to snow). Outlook... The overall weather pattern through late next week strongly favors shortwave movement within upper troughing that occurs almost every other day. Each system will feature varying degrees of precipitation chances (type mainly snow, save for short periods of rain at southern terminals), intensities, and either the continuation of or reintroduction to MVFR-IFR restrictions. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...Shallenberger NEAR TERM...Milcarek/Lupo SHORT TERM...Shallenberger LONG TERM...Shallenberger AVIATION...Frazier