Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
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722 FXUS61 KPBZ 060107 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 907 PM EDT Fri Jul 5 2024 .SYNOPSIS... Shortwave passage will create periods of moderate rain showers with low probability thunder through tonight, along with a non zero flood threat. Dry weather returns Saturday through Monday with temperature rising well above normal by Monday afternoon. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... KEY MESSAGES: - Shower and thunderstorm activity will become more widespread tonight, with a still-present risk of localized flash flooding. The risk of damaging wind gusts remains low. ------------------------------------------------------------------- Earlier strong storms, currently still south and west of Pittsburgh, have weakened considerably as they have crossed into the CWA, as they entered an area more hostile to convective maintenance. Rain rates have slackened as activity has become more stratiform in nature, and only a few cloud flashes have been observed recently. Adjusted near-term PoPs for radar trends. Much of this activity will lift off to the northeast by midnight. As a shortwave trough crosses overnight, there may be an uptick of precipitation once again. This is already occurring to some degree upstream in southern Ohio. A few thunderstorms remain possible, tapping into elevated instability. However, any severe risk has largely ended for the night with the loss of daytime heating. Flash flooding cannot be totally ruled out as high PWAT persists, but strong enough steering flow and relatively dry antecedent conditions should keep risk low. Passage of a surface trough and upper wave will diminish precipitation chances west to east and offer a slight reprieve from the warm, muggy conditions by morning. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY NIGHT/... KEY MESSAGES: - Dry and more seasonable weather returns on Saturday. - Rising temperature likely through Monday as dry weather persists. ------------------------------------------------------------------- Drier southwest flow and ridging at the surface will support dry weather Saturday. Lingering morning stratus clouds are expected to break up with a scattered to broken cumulus field developing in the late morning to early afternoon; weak cool advection plus the cloud cover should aid temperature returning to more seasonal values. More notably for some, drier air will mix to the surface and bring relief to the region from the multiple day experience of humid conditions. Return flow as high pressure settles over the Atlantic will support rising temperature Sunday into Monday as the next upper trough system develops over the Central Plains. Heat risk concerns return as a result, though probabilities of seeing heat indices above advisory criteria remain low. && .LONG TERM /TUESDAY THROUGH FRIDAY/... KEY MESSAGES: - High probability for dry weather and slightly above average temperature the rest of the weekend. - Unsettled weather returns Tuesday through at least mid-week. ------------------------------------------------------------------- Ensemble consensus continues to favor an Upper Midwest trough lifting through the Great Lakes region Tuesday into Wednesday morning with a weak surface trough. Moist advection ahead of the wave is likely to foster a warm, humid environment translating to likely showers and thunderstorms ahead of the feature. Environmental conditions remain varied, but with ensemble means showing near 90F highs and 70F dewpoints, there appears to be at least a low probability for flash flood risk and potential other severe hazards. Variations become post-shortwave passage depending on high pressure strength to the north as well as potential pattern impact from the remnants of Hurricane Beryl. The main takeaways for the long range period is that 500mb mean heights suggest a continuation of near to above normal temperature and precipitation chances tied to shortwave movement. && .AVIATION /01Z SATURDAY THROUGH WEDNESDAY/... Remnant showers from a passing MCS in northern WV will briefly impact MGW (and potentially LBE) through 03Z. A brief period of MVFR to IFR vis may occur with convection. Otherwise, scattered showers north of MGW will continue to pass slowly from west to east ahead of a cold front. Cigs should lower to MVFR/IFR early Saturday morning with lingering low-level moisture; ZZV may experience MVFR to IFR fog between 09Z to 12Z if the cold front tracks through eastern Ohio before dawn. VFR conditions increase between 13Z to 16Z with diurnal heating and building high pressure. Scattered VFR low- lvl cu will likely develop with mixing of the boundary layer after 15Z. .Outlook... VFR conditions should persist into Sunday under high pressure. The next chance for widespread restrictions will be with our next system Tuesday. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...Frazier NEAR TERM...Frazier/CL SHORT TERM...Frazier LONG TERM...Frazier AVIATION...Hefferan/88