Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
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957 FXUS61 KPBZ 010939 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 539 AM EDT Wed May 1 2024 .SYNOPSIS... The remainder of the work week will be dry and warm. A slight cool down is expected this weekend with returning rain chances. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... KEY MESSAGES: - Warm and mostly sunny today under building high pressure. ------------------------------------------------------------------ Warm and dry weather is in store today with a weak upper ridge building overhead. Temperatures climb to around 80 degrees under mostly sunny skies and light winds. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... KEY MESSAGES: - Dry weather and above-normal temperatures continue through Thursday. ---------------------------------------------------------------- Dry weather and above-normal temperatures continue tonight into Thursday. A weak front pushes into the area from the northwest overnight but only brings a wind shift as convection will struggle to develop given the lack of moisture and ascent beneath the upper ridge. Temperatures settle into the 50s by early Thursday morning before climbing back into the 80s (upper 70s north of I-80) Thursday afternoon. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... KEY MESSAGES: - An unsettled pattern returns Friday through the weekend with above-average temperatures and periods of showers and thunderstorms favored. ------------------------------------------------------------------- High pressure will continue to support above-normal temps and dry conditions Thursday night with lows ranging from upper 50s south of I-80 to low 50s farther north. Ensembles continue to indicate a more active weather pattern setting up Friday into the weekend as an upper level trough pushes eastward over the Great Lakes, shunting the ridge axis southeastward and bringing a deep-layer southwest flow to the region. Periods of showers and thunderstorms can be expected Friday afternoon through the weekend, though exact timing and intensity of any given round of convection remains uncertain due to the complex nature of the more active pattern. The latest ensemble runs continue to paint Friday night and Saturday as the most likely periods to see widespread shower and thunderstorm activity, though there also continues to be some signal for scattered convection lingering through Sunday and even into early next week. At this time, a widespread severe weather threat appears unlikely due to a lack of notable instability or bulk shear. The same can be said about the threat for a widespread flood threat, as ensemble probabilities for widespread rainfall amounts of an inch or greater remain low (30% or less) across the area during any given 24-hour period this weekend. That said, heavier rain rates in thunderstorms could result in a localized minor flood threat for low-lying and urban areas. For this reason, the Weather Prediction Center has highlighted a Marginal Risk for excessive rainfall across eastern OH, western PA, and northern WV on Saturday. Stay tuned for more details on timing and impacts as we get closer to the weekend. As for temperatures, Friday continues to look like the warmest day of the week, with highs potentially reaching the mid to upper 80s across much of the area. Ensembles guidance continues to indicate a 70% or greater chance of exceeding 85 degrees for areas south of I-80. Temperatures Saturday through Monday also trend above normal, but remain in the 70s due to thickening cloud cover and an increasing coverage of showers and storms. && .AVIATION /10Z WEDNESDAY THROUGH SUNDAY/... Building high pressure has resulted in light and variable to calm wind with just a few passing cirrus, but also for fog/stratus development with restrictions to IFR/LIFR for MGW, LBE, and most recently HLG. Where wind has gone calm, low-level moisture has manifested as dense fog. However, where wind has remained slightly elevated, stratus has been predominant. Sites have even bounced around between IFR/LIFR VIS to IFR/LIFR CIG overnight dependent on variable wind speed. Hi-res model ensemble guidance suggests high confidence (60-80%) MVFR or lower VIS at MGW/LBE/HLG with the highest probability for LIFR at HLG (~60%); probabilities for LIFR at MGW creep up to 30-40%, so have included a TEMPO group to account for this. AGC/PIT have a low (<30%) chance of seeing VIS restrictions creep in, but with little to no precip observed in the area and higher dew point depressions have left mention out. VFR quickly returns after 13z Wednesday with high confidence as mixing commences and ridging builds further. A passing warm front will bring a modest increase in mid-level clouds come late morning/early afternoon, but otherwise will see southwest wind prevail around 5-10 knots. Cirrus thicken late Wednesday night with increasing upper level moisture. .Outlook... VFR conditions are expected to continue into Thursday under high pressure. The next chance for restrictions comes late Friday into early Saturday with passing low pressure. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...Cermak/Milcarek NEAR TERM...Cermak/CL SHORT TERM...Cermak/Milcarek LONG TERM...Cermak AVIATION...MLB