Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
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940 FXUS61 KPBZ 090648 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 248 AM EDT Thu May 9 2024 .SYNOPSIS... Showers and thunderstorms will return, mainly south of Pittsburgh, as a frontal boundary turns around and approaches as a warm front. Thereafter, unsettled weather continues, with periodic showers and storms Thursday through Saturday. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... KEY MESSAGES: - A returning frontal boundary will provide shower and thunderstorm chances late tonight, mainly south of Pittsburgh. ------------------------------------------------------------------- A frontal boundary positioned south of our region will begin to lift back north as a warm front overnight as 500mb heights begin to rise. Clouds will increase as a result, with contribution of high clouds from convection well to the south. With lift supplied by the front and a shot of isentropic lift, showers and thunderstorms will begin to fire in the southern CWA after 06Z, with chances greatest near and south of the Mason-Dixon Line. At this time, feel that the threat of severe thunderstorms overnight is low. Shear appears to be weak overall, and storms are likely to be elevated. DCAPE appears marginal for a downburst threat, but perhaps some hail could be realized from the stronger storms given elevated CAPE. Overnight low temperatures will end up some 5 to 10 degrees above normal, given the cloud increase. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/... KEY MESSAGES: - Showers/storms return early Thursday through Friday. ------------------------------------------------------------------- A sfc low approaching from the west will track along a boundary in the vicinity of the Mason- Dixon line on Thursday, followed by a shortwave on Friday. Another Marginal risk for flooding seems to be the case. This will depend on where the main axis of moisture sets up. Hi res models suggest this may be a bit further south than the Tuesday night activity and may be less impactful. NBM probs in DESI do surpass 40% for 1 inch for the area south of the Mason Dixon. Thus, any flooding issues will be dependent on training in WV or any heavier rainfall over the OH and PA areas that received heavy rainfall already. Strong height falls on Friday usher in a cooler pattern with a long wave trough position in the east. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... KEY MESSAGES: - Ensembles suggest a wet pattern into the weekend. - Cooler temperatures arrive by late week with highs in the 60s this weekend. ------------------------------------------------------------------- By Friday night into Saturday, another fast moving shortwave dives southeast in northwest flow bringing another round of showers to the area. Overall, a rather damp weekend is on tap. The slow moving trough will keep rain chances through Sunday as well. Temperatures through Sunday will be 5-10 degrees below the seasonal normal of about 70 this time of year. Some moderation of temperatures is likely Monday and Tuesday as heights rise and flow turns from northwest to more westerly, though there is a possibility of another trough dropping over the northeast on Tuesday keeping things a bit cooler than currently forecast. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... MVFR cig restrictions with rain will return from the south after 12Z as a low pressure system tracks through the region. Probability for thunder is expected to increase after 16Z with daytime heating. A few storms south of PIT may be severe in the afternoon/evening. Rain should generally taper off overnight. It becomes increasingly likely that cigs will lower to IFR/LIFR from the south after 00Z Friday with lingering moisture and cooler conditions behind a cold front. .Outlook... Restrictions will likely continue through Friday afternoon with lingering low-level moisture and cold advection from the northeast. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...CL NEAR TERM...CL SHORT TERM...Shallenberger/88 LONG TERM...Shallenberger AVIATION...Rackley