Area Forecast Discussion
Issued by NWS Cleveland, OH
Issued by NWS Cleveland, OH
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620 FXUS61 KCLE 261748 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 148 PM EDT Thu Sep 26 2024 .SYNOPSIS... A weak cold front will gradually move east today as high pressure briefly builds into the Great Lakes region this afternoon. The tropical remnant low of Helene enters the Ohio Valley on Friday night, where it will remain through the weekend as it rapidly weakens. && .NEAR TERM /THROUGH FRIDAY/... 9:40 AM Update: Just some minor tweaks needed to the POP and sky grids through this afternoon. A few showers are ongoing from near Wooster to Akron with dry weather elsewhere. Adjusted POPs a bit to increase them in that corridor this morning. Previous Discussion: A weak cold front continues to progress eastward this morning, with modest 850-925mb moisture and frontogenesis leading to some scattered rain showers generally south of a KMFD-KCLE-KERI line. Should see these showers dissipate as the front departs to the southeast and high pressure builds into the Great Lakes region, skirting the northern part of the forecast area this afternoon into tonight. After making landfall later this evening, Helene will work its way northward, rapidly dissipating as it does so. Even so, the northernmost rain bands will move in from the south during the day Friday, with rain chances increasing compared to previous forecasts, with KFDY-KMFD-KCAK and areas south increasing to 60-70% PoPs. Because of how quickly Helene dissipate as it approaches the Ohio Valley, there will be a minimal to no flood risk for our forecast area, though there could be a modest chance for a beneficial 0.25-0.50" QPE for some parts of central Ohio. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/... The remnants of Helene will settle over the Ohio Valley with the upper low beginning to creep north or east into the area during the short term period. Moisture will continue to stream north into the area over the weekend with periodic showers and perhaps isolated thunderstorms possible. Showers will be hit and miss and generally light so do not anticipate a complete washout or a drought- buster. Coverage will be highest during peak diurnal heating Saturday and Sunday with the best rain chances in the southwestern part of the CWA, which will be closer to the surface low. High temperatures will be in the 70s each day with lows in the upper 50s to lower 60s anticipated each night. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... Upper low will finally drift east into the Mid-Atlantic Monday and off the East Coast Tuesday. However, an upper trough may linger somewhere in the eastern vicinity of the CWA through as late as Tuesday morning as a ridge attempts to build over the Lower Great Lakes. If the trough remains to the east of the area, a drier forecast may pan out, but any residual troughing over the local area could result in continued scattered shower chances. Maintained slight chance to chance PoPs for the time being, but it`s possible that the forecast improves in the upcoming days. An upper trough and surface cold front will move east/southeast across the Upper Great Lakes and across the region at some point Tuesday and possibly into Wednesday, but there`s quite a bit of uncertainty in the timing/strength of the upper trough. Regardless, this feature will bring additional precipitation chances to the local area towards the end of the long term period. Temperatures will generally be near to a couple degrees above normal early next week, but cold air advection behind the aforementioned cold front may usher slightly below normal temperatures into the region Wednesday. && .AVIATION /18Z Thursday THROUGH Tuesday/... MVFR to locally IFR ceilings persist near a slow-moving frontal boundary across eastern Ohio and northwestern PA, including at MFD, YNG, and ERI. The front will continue to gradually push south and weaken into this evening which should allow VFR to return. Otherwise, we remain beneath expansive VFR clouds streaming northward from Hurricane Helene. As the system makes landfall and begins pushing inland tonight into Friday, interaction with an upper-level disturbance will help draw deeper moisture northward. This will allow for cloud bases to gradually lower from south to north on Friday with some light rain potentially getting into MFD before 18z. All terminals, except for ERI and perhaps YNG, have a decent chance to see some rain after 18z with a period of MVFR visibility possible. Except MVFR cloud bases to overspread most sites (except for ERI) from south to north through the day Friday. The initial timing of MVFR is somewhat uncertain at CLE due to some downslope flow. Winds will be out of the east-northeast through the TAF period. Speeds will remain modest and 12 knots or less through early Friday. Speeds and gusts will increase into Friday afternoon. Sustained winds of 20-25 knots and gusts to 35 knots are looking increasingly likely at TOL, FDY and MFD, especially between 18z Friday and 0z Saturday. Speeds will gradually diminish to the east/northeast, though gusts up to 30 knots will be possible at CLE and CAK, with gusts 20-25 knots towards YNG and ERI. Outlook...Periods of non-VFR are possible with scattered rain showers and low ceilings Friday afternoon through Monday. && .MARINE... Light and variable winds this morning will shift to the northeast and increase to 10 to 15 knots this afternoon. Flow will continue to increase over Lake Erie as Helene moves inland late tonight into Friday with winds peaking at 25 to 30 knots with gusts to 35 knots Friday afternoon into Friday evening. The highest winds and waves will be in the western and central basins of the lake. Winds diminish to 10 to 20 knots Saturday into Sunday. Small Craft Advisories will be needed Friday and Saturday and may continue from roughly The Islands to Avon Point through Sunday. Expect winds to shift to the east/southeast and diminish further Monday. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...Saunders NEAR TERM...Saunders/Sullivan SHORT TERM...Maines LONG TERM...Maines AVIATION...Sullivan MARINE...Maines