561 FXUS61 KCLE 310806 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 406 AM EDT Sat Aug 31 2019 .SYNOPSIS... High pressure across the western Great Lakes will build east towards New England by Sunday. Meanwhile an upper level disturbance will cross the region Sunday then shift east on Monday. A weak front will settle south across the eastern Great Lakes Monday night. && .NEAR TERM /THROUGH SUNDAY/... High pressure across the western Great Lakes and Midwest will expand east across the region today, then shift east to New England through Sunday. Considerable dry air will be over the region in the 850- 700mb layer while high cloud thickens and streams overhead today. The combination of the high cloud and a slightly cooler airmass across the north will keep temperatures down 4-5 degrees from yesterdays highs in the mid 70s. The airmass will continue to moisten overnight into Sunday as the high builds to the east. Dewpoints will creep back up into the mid 60s allowing ML CAPE values of 1000 J/kg or more to develop, especially across inland portions of NE Ohio. Thunderstorms are expected to develop during the afternoon as shortwave energy moves east across the Southern Great Lakes Region. Low level convergence will be maximized downwind of Lake Erie where northeasterly flow off the lake will merge with a weak warm front attempting to lift north. This is where storms are expected to initiate first before expanding on outflow boundaries. Scattered to numerous coverage is expected across inland Northeast Ohio and Northwest Pennsylvania during the mid to late afternoon with lower pops across Northwest Ohio. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/... A surface trough and accompanying mid level disturbance will be lifting northeast out of the area Sunday night into Monday. Shower/thunderstorm chances will be present across the area Sunday night, gradually lifting northeast of the area into Monday. Low shower/thunderstorm chances will persist through the day Monday, especially across the eastern part of the area, as a secondary mid level wave digs southeast through the Great Lakes. The best forcing will remain north of the area, so only low chance/slight chance pops warranted for this period. Brief ridging builds east across the area Monday night through Tuesday, with mainly dry conditions expected. A stronger low will move east across the northern Great Lakes Tuesday into Tuesday night, forcing a cold front southeast towards the area Tuesday night. This will allow shower/thunderstorm chances to increase across the area mainly after midnight Tuesday night. Highs will generally be in the upper 70s to low 80s across the area, and a few degrees cooler across the higher terrain of NW PA. Highs will be a few degrees warmer Tuesday with a brief period of stout WAA with the ridge quickly moving east of the area. Mid 80s will be common across the area on Tuesday. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... A quiet second half of the week is expected after the cold front moves east through the area Wednesday. A few showers, possibly a rumble of thunder, will be possible early in the day east, but the front should be out of the area by the afternoon with dry conditions prevailing. High pressure builds east across the region into the weekend, with dry conditions and near to slightly below normal temperatures. && .AVIATION /06Z Saturday THROUGH Wednesday/... VFR expected through the TAF cycle with varying degrees of high level clouds. Clouds will start to lower Saturday night towards 10K feet. Light north to east winds of 10 knots or less are expected except near Lake Erie where a few gusts to 18-20 knots are possible during the afternoon. OUTLOOK...Non VFR for scattered showers and thunderstorms late Sunday afternoon through Monday. && .MARINE... Northeast winds will ramp up a bit this morning as high pressure builds east across the Great Lakes. Winds will generally remain in the 10-20 knot range through the day. Given the long northeasterly fetch through the day, waves may build into the 2-4 feet range from the Islands east to Cleveland, especially on the northeast facing beaches. Will opt for a moderate risk of waves and currents, and expect conditions to remain just below small craft advisory criteria. Winds will decrease tonight into Sunday as the high moves over the lakes into New England. Flow will remain generally light Monday and Monday night before increasing out of the south to southwest Tuesday ahead of an approaching cold front. Winds will become northwesterly to northerly early Wednesday as the front moves east across the lake. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...KEC NEAR TERM...KEC SHORT TERM...Greenawalt LONG TERM...Greenawalt AVIATION...KEC MARINE...Greenawalt