FXUS61 KCLE 040634 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 134 AM EST Wed Dec 4 2024 .SYNOPSIS... High pressure quickly glides west to east south of the area through this evening. Deepening low pressure glides east across Ontario while extending a strong cold front across the area Wednesday night into Thursday. Lingering troughing remains in place over Lake Erie on Thursday before high pressure builds back in by Friday. && .NEAR TERM /THROUGH TODAY/... 9:30 PM Update... Removed PoPs from Erie County, PA the rest of the evening as the last of the lake-effect snow has pushed offshore. This will yield dry conditions areawide overnight. Light radar returns moving into western Ohio is virga due to mid-level warm air advection and moist isentropic ascent ahead of the approaching clipper. Low-level dry air will hold firm through the night, so only expect a thickening cloud deck. 6:30 PM Update... The persistent, 5 day long lake-effect snow event is finally over! The final bands over Erie County, PA are rapidly pushing northward in response to strengthening warm air advection and southwesterly flow. This will send the last of the snow showers over northeastern Erie County out over the lake by 03Z with just an additional 1-2 inches between now and then. After coordination with BUF, will expire the warnings on schedule at 00Z. Otherwise, the forecast remains on track through this evening. Original Discussion... Lake effect snow showers associated with a Lake Huron connection will gradually move north and exit the local area this evening as low level ridging builds over the region and winds favor a southwesterly component. Have kept the Lake Effect Snow Warning for Erie and Crawford Counties in Pennsylvania in place through 7 PM tonight. We'll have a brief window of dry weather as the low level ridge axis remains overhead before a deepening low pressure system moving across Ontario impacts the region. We'll remain fairly cloudy tonight with overnight low temperatures dropping to the low to mid 20s areawide. && .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... A very active short term period in store as a multi-hazard winter weather system and Arctic front will impact the area Wednesday evening into the end of the week. Nearly all hazards are on the table with this system including additional snowfall, strong winds, blowing snow, snow squalls, and cold temperatures. A Winter Storm Watch is in effect from late Wednesday afternoon through early Friday morning for Cuyahoga, Summit, Lake, Geauga, Portage, Ashtabula, Trumbull Counties in Ohio and Erie and Crawford Counties in Pennsylvania. Ahead of the front, a strong low level jet characterized by 850mb winds between 55 and 65 knots moves overhead the region. Strong southerly to southwesterly surface winds are expected to increase to 25-30 MPH with gusts to 40+ MPH by Wednesday afternoon. Highest wind speeds and gusts will likely occur along and west of I-71 where the better jet support lies and along the Lake Erie lakeshore given the southerly wind component favorable for downsloping. Fairly moist airmass in addition to the upper jet ahead of the cold front will support widespread rain and snow showers across the local area beginning Wednesday afternoon. As the Arctic front approaches the local area by Wednesday night, expect for conditions to deteriorate further. Rapidly dropping temperatures, the existing snowpack, new snowfall, and strong winds in excess of 35 MPH will likely lead to some travel impacts for the Thursday morning commute either in the way of snow squalls and/or blowing snow. By Thursday, the Arctic front will have crossed the region with mean layer flow turning northwesterly behind the front. 850 mb temperatures quickly plummet to the -12C to -18C range by Thursday. Cooler surface temperatures coupled with strong northwesterly winds will allow for a window of Wind Chill temperatures to drop into the single digits during the early morning hours on Thursday and Friday. Outside of the Winter Storm Watch, have roughly 1-3 inches of snowfall with the majority of it falling late Wednesday into the day Thursday. The system turns more lake effect in nature behind the Arctic front. The aforementioned cool 850 mb temperatures in addition to a relatively warm Lake Erie will result in another round of efficient lake effect snowfall across the traditional Snowbelt. The current storm total snowfall for Snowbelt counties ranges anywhere between 6-8 inches with locally higher amounts in excess of 12 inches possible where snow bands persist. && .LONG TERM /FRIDAY THROUGH TUESDAY/... Lake effect snow is likely to continue into the day Friday with an additional 1 or 2 inches of snow in the primary snowbelt in Northeast Ohio and Northwest Pennsylvania with locally higher amounts in higher terrain areas of Northwest Pennsylvania. High pressure builds in to the south so any lake effect snow bands that have persisted during the day Friday should shift northward to mainly offshore Lake Erie by late Friday night into Saturday. By Sunday high pressure shifts eastward to off the Atlantic coast. Temperatures warm up on Sunday on the backside of the departing high pressure with high temperatures into the 40s. Broad upper-level trough and surface low approaches from the west with periods of rain expected Monday and Tuesday. Temperatures will continue to rise, with highs near 50 on Monday. && .AVIATION /06Z Wednesday THROUGH Sunday/... The airspace is in a reprieve of non-VFR at the moment with high pressure to the south of the area. With moisture entering from the southwest, some MVFR is located across Indiana and is spreading into Northwest Ohio. Expect this cloud deck to continue across the airspace and allow for some MVFR by late morning for most terminals. There could be a brief break in the MVFR as this deck has a back edge before a cold front. However, a strengthening low pressure system will enter the region today and extend a cold front across the area. Enough lift ahead of the main front may allow for some scattered rain and/or snow showers and ceilings with these would likely be MVFR. The Arctic cold front will cross toward the end of the TAF period and bring a brief window with possible snow squalls. Have PROB30s for a one or two hour window for low visibility snow, low ceilings, and increased winds as this feature moves through the airspace. Behind the front, snow showers will overtake the region with the highest impact snow in NE OH and NW PA, where trends to IFR will take place. Winds through the period will be problematic. Winds are already increasing out of the southwest with gusts in the 20 to 25 kt range. Wind gusts will be in the 30 to 35 kt range this afternoon and then abruptly shift to the west with the cold front passage this evening. Outlook...Non-VFR likely in snow through early Friday with the most pessimistic conditions across NE Ohio and NW PA. Non-VFR possible in NE OH and NW PA with lingering snow showers Saturday. && .MARINE... Southwest flow will be on the rise in the evening into tonight, peaking during the day Wednesday. Offshore flow will mean nearshore waters will be around 20-30 knots with speeds closer to 35 knots in the open waters. A cold front will move east across Lake Erie Wednesday night, with flow quickly becoming west Wednesday night and then northwest by Thursday morning, with gale force winds expected with and behind the cold front through Thursday. A gale warning will be in effect Wednesday evening through early Thursday afternoon west of the islands and the Wednesday morning through Thursday evening east of the islands. A low water advisory may also be needed for the western basin of Lake Erie at various points Wednesday evening through Thursday afternoon. A small craft advisory is in effect until the start of the gale warning starts and will likely be needed again through the end of the week and into the weekend. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...Winter Storm Watch from this afternoon through late Thursday night for OHZ011>014-021>023-089. PA...Winter Storm Watch from this afternoon through late Thursday night for PAZ001>003. MARINE...Small Craft Advisory until 7 PM EST this evening for LEZ142- 143. Low Water Advisory until 1 AM EST Friday for LEZ142-143-162- 163. Gale Warning from 7 PM this evening to 1 PM EST Thursday for LEZ142-143-162-163. Small Craft Advisory until 7 AM EST this morning for LEZ144>149. Gale Warning from 7 AM this morning to 7 PM EST Thursday for LEZ144>149-164>169. && $$ SYNOPSIS...Iverson NEAR TERM...Garuckas/Iverson SHORT TERM...Iverson LONG TERM...Saunders AVIATION...Sefcovic MARINE...Saunders