651 FXUS61 KCLE 231151 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 651 AM EST Tue Feb 23 2021 .SYNOPSIS... A trough moves eastward through our region this morning and is followed by a ridge building from the south and west through tonight. As a low moves eastward across the central Great Lakes on Wednesday, it will drag a cold front through northern Ohio and northwest Pennsylvania. Another high pressure ridge builds eastward by Wednesday night and Thursday. && .NEAR TERM /THROUGH WEDNESDAY/... A trough at the surface and aloft traverses our CWA this morning and exits eastward by midday. Isentropic lift aloft and low- level convergence along the surface trough axis will likely allow a mix of snow and rain showers to affect northern OH and northwest PA, especially northeast of a Toledo to Mansfield to Pittsburgh line. Model soundings continue to suggest a surface- based melting layer will likely reside over most of our CWA and be deep enough for the snow to mix with rain, especially outside the higher terrain in northwest PA. The time window during which precip is most likely to occur spans 5 AM to 10 AM EST this morning. Any snow accumulations will likely be less than 1 inch, but localized accumulations of 1 to 2 inches are expected in the higher terrain of northwest PA. Odds favor fair weather this afternoon through tonight as high pressure at the surface and aloft builds eastward. Highs should reach the mid 30's to lower 40's this afternoon. Lows should reach the upper 20's to lower 30's overnight tonight before temperatures moderate slightly toward daybreak. The moderating temperatures will be in response to low-level WAA on the backside of the departing high pressure ridge. On Wednesday, a shortwave trough advances eastward from the Upper Midwest to the eastern Great Lakes, while the accompanying surface low advances from the western Great Lakes toward southern QC and northern New England. This low will drag a surface cold front eastward through our CWA Wednesday afternoon. Low-level WAA should allow highs to reach the 40's prior to the frontal passage. Isentropic lift aloft and low-level convergence along the cold front will likely generate isolated to scattered rain showers along and ahead of the front. Precip should end quickly behind the front as surface ridging builds eastward. By nightfall, the only remaining precip in our CWA should be scattered and light lake-enhanced rain and snow showers in northwest PA and perhaps far-northeast OH. No snow accumulations are expected by sunset. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... A cold front will be exiting the area Wednesday night as low pressure moves east away from the Great Lakes. High pressure will briefly build northeast into the area Thursday before a mid level shortwave and associated low level trough moves southeast across the Great Lakes Thursday night. Surface ridging will build east through the area Thursday night through Friday before becoming centered over the Mid Atlantic. Most of the period looks to be dry aside from some slight chance pops across the snow belt Wednesday night and again Thursday night behind the respective front/trough, with minimal moisture and weak lake induced instability. Highs on Thursday will be in the low to upper 30s across the area, with mid 30s to low 40s for highs on Friday. && .LONG TERM /SATURDAY THROUGH MONDAY/... Precip chances will increase across the area Friday night into Saturday, as a mid level shortwave and attendant surface low move from the Plains through the Great Lakes, and isentropic ascent increases northward through the Ohio valley into the lower Great Lakes. Precip could start out as a mix Friday night before transitioning to mainly rain early Saturday and diminishing altogether Saturday afternoon. High pressure will build east across the area late Saturday into Sunday providing mainly dry conditions. Low pressure will move northeast through the Ohio valley late Sunday through Monday, which may bring precip chances back to the area. Models diverge a bit with the overall synoptic pattern Sunday into Monday, with uncertainty regarding a northern stream low and cold front moving into the Great Lakes, so confidence is low in pops/temps for Monday. Highs Saturday and Sunday should reach the mid to upper 40s, and it wouldn't be out of the question to see a few locations reach 50 across the area. Highs Monday are currently forecasted to be in the low to mid 40s. && .AVIATION /12Z Tuesday THROUGH Saturday/... A surface trough sweeps eastward across our region through about 15Z/Tues. Behind the trough, a surface high pressure ridge builds eastward through about 06Z/Wed and is followed by another trough overspreading our region from the west as the embedded low moves from the Upper MS Valley toward northern Lower MI by 12Z/Wed. Southwesterly to westerly surface winds of about 10 to 20 knots are expected through the TAF period. Occasional gusts as high as 25 knots are forecast through this early evening. Ceilings will be prevalent through the TAF period and should fluctuate between VFR and MVFR. Fair weather is expected at most terminals. However, the first trough should be accompanied by periods of light snow, perhaps mixed with rain, and MVFR visibility through about 15Z/Tues. Brief IFR ceilings and visibility may accompany steadier precip. The best potential for precip exists northeast of a KCLE to KCAK to KPIT line. Outlook...Non-VFR possible with periods of snow and/or rain Wednesday, Wednesday night, Thursday night, and Friday night through Saturday. && .MARINE... Southwest winds will increase out of the southwest this morning as a trough moves east across the lake, peaking around 25 kts before subsiding back to 10-20 kts this afternoon and evening. Winds become southerly across the lake late tonight into Wednesday ahead of low pressure moving into the central Lakes. As the low moves east out of the Great Lakes, it will bring a cold front across the lake Wednesday, with winds becoming southwest in the 20-30 kts range again late Wednesday, subsiding and becoming northwest Wednesday night. Surface high pressure will dominate over the lake Thursday into Friday, with light and variable winds becoming southerly as the high builds east late Friday. Winds will increase out of the south again Friday night into Saturday ahead of another low moving into the lakes. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...Jaszka NEAR TERM...Jaszka SHORT TERM...Greenawalt LONG TERM...Greenawalt AVIATION...Jaszka MARINE...Greenawalt