Area Forecast Discussion
Issued by NWS Cleveland, OH
Issued by NWS Cleveland, OH
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945 FXUS61 KCLE 210755 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 355 AM EDT Sat Sep 21 2024 .SYNOPSIS... A cold front will continue to track east across the area through this afternoon and exit to the east by this evening. High pressure briefly returns tonight into Sunday morning before a series of systems cross the region Sunday night through the first half of the week. && .NEAR TERM /THROUGH SUNDAY/... Showers with isolated elevated thunderstorms have developed ahead of a weak trough axis/cold front that is currently moving east across the local area. These showers will continue to track east through early this morning. However, the lower levels are still quite dry, so any showers/thunderstorms that manage to develop over the area will be hit and miss and rainfall rates may be on the lighter side. The front will continue to track east across the area today; overall instability, coverage, and rainfall chances will remain low until diurnal instability increases this afternoon. By then, the front will likely be near or a bit east of the OH/PA border so showers/thunderstorms may begin to initiate in the CWA before moving east outside of the local area. There may be a narrow corridor of marginal instability (MLCAPE values of 500-1200 J/kg) and shear values of 20-30 knots across far eastern NE OH and NW PA so can`t rule out a few thunderstorms. If thunderstorms do develop, there may be a low- end chance of hail and gusty winds, but the greatest severe risk will reside to the east of the CWA where diurnal destabilization and forcing will be more favorable. Dry weather is expected behind the front and this will continue through tonight and the first half of Sunday. Patchy fog is possible overnight, primarily in areas that receive rainfall, but cloud cover may be a bit too high for radiational cooling. Isentropic ascent near and behind a warm front will allow rain chances to increase from the west starting Sunday afternoon, but the higher PoPs won`t occur until Sunday night (see Short Term Discussion below). Expect highs to climb into the mid to upper 80s west of I-71 today with upper 70s to lower 80s anticipated east. Tonight`s lows will fall into the upper 50s to lower 60s. Maximum temps will generally be in the 80s Sunday, although NW PA will likely see highs in the upper 70s. The warmest temps in the mid to upper 80s will once again be found west of I-71. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/... The short term forecast will not be a total drought buster, but a series of systems through the region will allow for the best chances for widespread rainfall in some time and will at least attempt at holding the drought at where it is through the end of the month. A cold front will approach the region for Sunday night into Monday, coincident with an upper level shortwave that will breakdown the upper ridge over the region for much of the weekend. Will continue a mix of likely to categorical PoPs for Sunday night into Monday with the front itself. There seems to be a possible lull in precipitation on Monday night as the front departs and another shortwave organizes to the west for Tuesday and have a down trend in PoPs to slight chance to chance for Monday night. The shortwave will move through on Tuesday with a low pressure through the region and have PoPs increasing again to likely. Overall, looking at an average of 1 to 1.5 inches of total rainfall by Tuesday night, which will help some of the rain deficits of the region and curb the drought from worsening. Temperatures through the period will trend toward normal. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... Low confidence in the long term forecast as there are two divergent solutions in the extended guidance. The forecast changes are based on the final path of the trough that will swing through the Great Lakes region starting on Wednesday. Some guidance members have the trough devolving into a closed upper low that will settle over the Midwest and Ohio Valley during the middle-to-end of the week. This would allow for a more wet forecast with continuous rain chances across the local area. Other guidance members have the energy of this midweek trough splitting with some energy moving through the region and extending a trough or even a closed low feature into New England with the other piece of energy parting well south over the south central United States. This would set up a blocking pattern with the local area on the backside of a trough with subsidence and overall drier conditions. There are therefore a wide span of options with the forecast and general low confidence in how much rain could occur in the region. Will go with generally lower PoPs than the previous forecast given more solutions presenting dry. Temperatures through the period will be near normal. && .AVIATION /06Z Saturday THROUGH Wednesday/... Some elevated showers have developed over Lake Erie, although there`s still quite a bit of dry air over the local area so any overnight showers that manage to develop over land may not reach the surface or will be very light. There may be a brief period of non-VFR conditions in fog at KTOL early this morning, but it`s possible that the lower visibilities/ceilings remain to the west of the terminal. Additional diurnally-enhanced showers and perhaps a few thunderstorms may develop in the vicinity of KERI late this morning into early this afternoon as a cold front pushes east into PA, however activity will be isolated and the higher coverage will occur when the front is to the east of the local area this afternoon. Have VCSH at KERI between 15Z and 18Z. Light and variable/southeast winds will gradually shift to the west/northwest and increase to 5 to 10 knots behind the cold front today. Expect winds to become light and variable after 00Z Sunday. Outlook...Non-VFR possible in periodic showers and thunderstorms Sunday evening through Wednesday. && .MARINE... A front will move across the lake this morning and bring westerly flow to the area. Winds should remain at 10 kts or so and there could be some waves of 1 to 2 ft over the central and eastern basins. High pressure will return for tonight into Sunday and bring northeast to east flow tonight, followed by offshore flow on Sunday. Likely all last week, suspect that easterly flow will develop during the day on Sunday with a push of stronger winds in the afternoon. A cold front will approach the lake on Sunday night and southerly flow will take hold and increase into Monday to about 15 kt as the front crosses the lake. The front will be east of the lake by Monday night and west to northwest flow will be favored behind the cold front. A low pressure system will move through the central Great Lakes on Tuesday and southerly flow will return. Another cold front will cross the lake behind the low for Wednesday and westerly flow will return. Overall, low probability in any marine headlines at this time but there could be some windows of unpleasant marine weather conditions with the various fronts moving across the lake. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...Maines NEAR TERM...Maines SHORT TERM...Sefcovic LONG TERM...Sefcovic AVIATION...Maines MARINE...Sefcovic