339 FXUS61 KCLE 111111 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 711 AM EDT Fri Apr 11 2025 .SYNOPSIS... Weak low pressure over Upstate New York will get absorbed by a larger low pressure system undercutting the region to the south and will move off the Mid-Atlantic coast tonight. High pressure will enter the region for Saturday. A warm front will cross the area on Sunday. && .NEAR TERM /THROUGH SATURDAY/... Minor changes to the forecast this morning. Some clearing has entered Northwest Ohio and the Toledo area, but clouds will try to refill into the area later this AM. Otherwise, low clouds and fog persist into NW PA and far NE OH and will largely remain for today. Previous Discussion... The pattern for today and tonight will largely stay the same for most of the forecast area. The area will be on the cooler, back side of a weak low pressure system to the east. Weak flow and high low level moisture will allow for widespread cloud cover for the entire area and intermittent instances of fog and/or very fine rain/drizzle in NE OH and NW PA. The energy of this low will transfer southeast into another system that will strengthen over the Mid-Atlantic coast. This will allow for high pressure to build in from the west with a much drier air mass. Clouds should be able to clear easily across Northwest Ohio by tonight. However, clouds will be more difficult to clear out downwind of Lake Erie until the surface high gets over the region on Saturday and allows for some backed flow to reduce the lake influence into the region. Highs will be cooler than normal in the 40s to lower 50s with lows in the 30s. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... High pressure will be overhead Saturday night, sliding to the east on Sunday as rather weak low pressure works from the central Plains towards the Upper Mississippi Valley. This low pressure will drift into the northern Great Lakes by Monday morning while deepening, lifting a warm front across the area Sunday night and pushing a cold front across the area Monday afternoon. Dry and chilly conditions are anticipated for Saturday night, with lows mainly in the 30s. Some weak moist isentropic lift ahead of the warm front on Sunday will increase clouds and may lead to some light rain shower activity...though the lift will be fairly modest with dry low-levels so POPs are low, generally in the 20% range. Highs on Sunday should warm into the 50s, with some chance at reaching 60 along the I-75 corridor. 20-30% POPs continue into Sunday night ahead of the warm front before lifting northeast of the area overnight. Lows Sunday night range from the mid 40s to low 50s. Monday should start dry and relatively milder before the cold front crosses from midday through the afternoon. Have 40-60% POPs with the frontal passage and those have room to come up still. Am not looking at a high-QPF rain event overall (NBM probabilities of rain staying <0.50" generally 90-95%), which makes sense given the stronger vorticity advection, height falls, and upper-level divergence staying to our north on Monday. However, with a strong front passing through near peak heating with some instability developing a round of showers and perhaps thunder is a decent likelihood. Deep-layer bulk shear values will be strong Monday afternoon, potentially on the order of 50kt...which along with the presence of an elevated mixed layer/EML (GFS and ECMWF suggesting 500-700mb lapse rates of 7- 8C/km) does at least raise an eyebrow for severe weather potential. Dew points likely staying <60F and air temperatures likely staying <70F should keep instability somewhat in check, though if we can manage 500-1000 J/KG of MLCAPE by Monday afternoon ahead of the front there`d be some potential for damaging winds/large hail given the strong deep-layer shear and presence of an EML. Greatest likelihood for building that much instability is just to our south, though trends will be worth monitoring. We should get into a relative dry break behind the front Monday night with lows falling back well into the 40s amid westerly breezes. && .LONG TERM /TUESDAY THROUGH THURSDAY/... A deep upper trough will be over the Great Lakes and digging into the Northeast U.S. on Tuesday. This trough will lift out on Wednesday, with the next rather deep trough digging into the Midwest and Great Lakes Thursday into Friday. Chilly, breezy, showery weather is expected for Tuesday, especially from Northeast OH into PA with relatively drier conditions farther west. It gets just chilly enough (850mb temperatures -6C to -9C) amid west-northwest flow for some lake effect precip Tuesday night into early Wednesday...which would likely mix with/change to snow Tuesday night with little to no accumulation. Surface high pressure builds in Wednesday as upper troughing starts lifting out, allowing for drier and clearing conditions. Rain chances begin returning Thursday into Thursday night as low pressure and a cold front ahead of the next rather impressive trough begin approaching from the west. Temperatures will be below normal for much of this period, though will briefly spike up towards normal on Thursday. && .AVIATION /12Z Friday THROUGH Tuesday/... Overall, not too many changes to the aviation forecast with this TAF package. Widespread non-VFR continues across the region with MVFR to the west and IFR/LIFR in the east. Some clearing skies are trying to enter the KTOL area and will be in and out through the morning. Abundant low level moisture and weak north flow will allow for IFR/LIFR conditions to continue through the TAF period with very slow improvement. High pressure will enter from the west this afternoon and will help scour out some of the clouds in Northwest Ohio, but the only terminals that may fully lose ceilings would be KTOL and KFDY. KCLE and KMFD could see ceilings improve to VFR by the end of the TAF period with the advancing high pressure, but it may be difficult given the air mass across the region and the colder north flow and there will be a drastic edge to the MVFR vs. clear skies. LIFR will stick around KERI and KYNG after 00z into Saturday. Outlook...Non-VFR ceilings and visibility will continue into Saturday across NE OH/NW PA. Scattered rain showers with non- VFR are possible this Monday afternoon through Tuesday. Isolated thunderstorms are possible Monday evening. && .MARINE... Northerly winds of 10-15 knots will lead to choppy conditions with waves of 1-3 feet through this evening. High pressure leads to light and variable winds with limited wave action Saturday and Saturday night. Winds shift south-southeast into Sunday but should stay under 15 knots through much of Sunday night, allowing fairly quiet marine conditions to continue through the weekend. Winds shift south- southwest and increase to 10-20 knots Monday morning, then shift southwest and at 15-20 knots Monday afternoon-night behind a cold front. 2-4 footers will begin building over the open waters on Monday and then push into the nearshore waters while increasing to 3- 5 feet Monday night, especially east of the Islands. Winds shift more westerly at 20-30 knots on Tuesday as a secondary trough axis pushes across the lake, with winds staying up at 15-25kt through Wednesday morning while shifting more northwesterly. This will maintain rough conditions Tuesday-Tuesday night with waves building to 5-10 feet east of the Islands and 3-6 feet to the west. Waves will gradually diminish on Wednesday. Small Craft Advisories will be needed for most or all of the lake from later Monday through at least Tuesday night with and behind the cold frontal passage. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...Sefcovic NEAR TERM...Sefcovic SHORT TERM...Sullivan LONG TERM...Sullivan AVIATION...Sefcovic MARINE...Sullivan