469 FXUS61 KCLE 190147 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 947 PM EDT Mon Oct 18 2021 .SYNOPSIS... High pressure will persist over the area through Wednesday before a low pressure system brings a cold front across the area Thursday. High pressure will return for the weekend. && .NEAR TERM /THROUGH TUESDAY NIGHT/... Good radiational cooling conditions are expected tonight as high pressure expands to the north and east. Winds are light which have allowed temperatures to drop quickly this evening. Some of the coolest locations as of 9 PM are 41 at Ravenna and 42 at Wooster. Expanded the mention of patchy frost to a few more counties in NE Ohio that tend to have some of the cooler valleys. Previous discussion...Quiet and average temperatures will persist through Tuesday night as high pressure builds across the eastern U.S. Lingering clouds in NE OH and NW PA will continue to gradually diminish this evening, allowing for clear skies across the area through Tuesday afternoon. Scattered high clouds will move in for Tuesday night, but will not result in any precipitation. High temperatures will climb into low 70s for western counties and the upper 60s for the eastern counties. Overnight lows will dip into the mid to low 40s tonight with a chance of reaching the upper 30s in areas with the greatest radiational cooling. Tuesday night will only drop into the upper 40s to low 50s as cloud cover will keep the area a bit warmer. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... On Wednesday, an upper-level ridge will be centered over the area with surface high pressure located south of the area with a high pressure ridge extended north across the Great Lakes region. Wednesday will easily be the warmest day of the forecast with most areas getting to at least 70. That all changes down the road though... By Wednesday night, an upper-level trough approaches the area, moving eastward across the southern Great Lakes Thursday into Thursday night. At the surface, this will result in a low of around 1005 mb moving east from lower Michigan Thursday morning to southern Quebec by Thursday night. A cold front associated with this low will move east across our region during the daytime Thursday. This will result in an area of rain showers moving east across the area ahead of the cold front very late Wednesday night through Thursday evening. A belt of higher dew points in the upper 50s will support MUCAPE of around 500 J/kg, resulting in isolated embedded thunderstorms. Strong mid-level westerlies will create bulk wind shear of 50-60 knots, which could potentially support severe thunderstorms, though that potential is severely limited by the marginal amount of instability. If low-level advection and/or daytime heating is stronger than currently forecast, we'll have to keep an eye on severe potential for Thursday afternoon, particularly for the eastern half of the CWA. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A second reinforcing cold front will move south across Lake Erie and northern Ohio late Thursday night into Friday. This will bring much colder temperatures to the region, along with lake effect rain showers Friday through at least Saturday afternoon. Below normal temperatures are expected through the long term with highs in the upper 50s to low 60s. Patchy frost may start to become possible Sunday and Monday morning as some models are forecasts low downs into the 30s. && .AVIATION /00Z Tuesday THROUGH Saturday/... VFR conditions with mostly clear skies and no restrictions to visibility are expected through the TAF cycle. High pressure will expand north into the area tonight with winds dropping to 6 knots or less at most locations. On Tuesday, southwest winds of 7-12 knots will develop with occasional gusts to around 20 knots at ERI. Outlook...Non-VFR possible in showers Wednesday night into Thursday. Non-VFR likely in lower ceilings Thursday night into Friday. && .MARINE... High pressure ridge continues to build over Lake Erie today, remaining over the area through Wednesday afternoon. As high pressure builds in, northwest winds (and associated waves) will diminish through this evening. For this reason, have allowed the Small Craft Advisory to expire. As the high pressure ridge axis shifts to the east, winds become west/southwest late tonight. Wind speeds approach 20 knots Tuesday afternoon through Wednesday morning, so another Small Craft Advisory may be needed for the eastern half of Lake Erie. There's a bit of a lull Wednesday afternoon through Wednesday night before wind speeds increase to 20- 30 knots ahead of an approaching low pressure system. That low pressure system and associated cold front move east across the Great Lakes region Wednesday night through Thursday night. Wind speeds of at least 20 knots on Lake Erie are possible through Thursday night and thus, another Small Craft Advisory will likely be needed again. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...Campbell NEAR TERM...Campbell/KEC SHORT TERM...Saunders LONG TERM...Saunders AVIATION...KEC MARINE...Saunders