459 FXUS61 KCLE 252337 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 737 PM EDT Tue Aug 25 2020 ...00z Aviation TAF and Evening Near Term Forecast Update... .SYNOPSIS... A weak cold front will stall south of the area tonight. A warm front will lift northeast across the area Tuesday. A stationary front will be draped across the Lower Great Lakes by Friday morning. On Saturday, a cold front will move east across the area. && .NEAR TERM /THROUGH WEDNESDAY NIGHT/... 700 pm update... We have taken out the precip chances for the rest of the evening as the convection from this afternoon has dissipate. It will be a fairly quiet night and slightly more "comfortable" airmass with lower dewpoints the further northeast you are located. Previous discussion... The severe thunderstorm watch has been cancelled for all counties in our CWA. Some residual showers may be possible through tonight, but the severe threat appears to be over. The strongest and most organized storms were located across portions of NW PA early this afternoon, associated with effective shear values of 35 to 40 knots. Another stronger, but less organized storm was located near Mansfield this afternoon, but is more pulsey in nature given effective shear around 15 to 20 knots. Nothing more than an isolated shower or thunderstorms is expected 6 PM, mainly along and south of US-30. Following the storms this afternoon and evening, a warm front will lift northeastward across the area by Wednesday morning. Showers and thunderstorms could be possible, mainly along the lakeshore from Toledo to Erie, associated with isentropic lift along the front. By the afternoon hours, instability will build across Northeast Ohio and Northwest Pennsylvania, accompanied by 35 to 40 knots of effective shear. If instability can be realized, some stronger storms capable of damaging winds and large hail could be possible along this instability gradient. The best chance for any stronger storms would be east of I-71 Wednesday afternoon and evening. By Wednesday evening, convection should begin to wane, although can't rule out some isolated showers with possibly a rumble of thunder across NW PA Wednesday night into Thursday morning. Temperatures throughout the near term will be above average and it will feel muggy with highs in the upper 80s to perhaps near 90. Lows will also be warm with temperatures in the lower 70s. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... Interesting forecast shaping up for the end of the week as moisture from the Gulf starts to stream northeast across the area while a front slowly sinks south out of Canada. Expecting some shower activity to reach the southeastern counties during the morning on Thursday but coverage and duration are not yet clear. The actual front is not expected to reach the area until evening on Thursday which leaves little forcing to initiate thunderstorms during the afternoon. Moderate instability is expected to develop across the region with temperatures in the upper 80s to lower 90s and could see a few thunderstorms during the afternoon so will keep a chance in the forecast. Pops ramp up to likely by Thursday evening as the front sags south and we should see convection fill in along this boundary. The frontal boundary will once again stall overhead Thursday night with PW values already up to around 2 inches. This is the beginning of a wet period as Gulf moisture continues to stream northeast across the area on Friday as the remnants of Hurricane Laura move north up the Mississippi Valley. Occasional showers with scattered thunderstorms are expected Friday into Friday night within this moisture rich environment. Meanwhile an upper level trough will move into the Upper Midwest with low pressure reaching the Central Great Lakes by Friday Night. This set-up could lead to heavy rainfall across the region as a stronger front develops and interacts with the tropical moisture. Most of the area will see 1 to 2 inches of rain with locally higher amounts possible. Wet conditions will continue until the cold front clears the area sometime on Saturday. && .LONG TERM /SATURDAY THROUGH TUESDAY/... A much cooler and drier airmass will arrive by Sunday with high temperatures in the 70s. Although the airmass dries out fairly quickly, would not be surprised to see some lake effect cloud off the east end of the lake on Sunday morning. This should mix out quickly on Sunday though as strong high pressure builds south out of Canada. Gradual warming will occur early next week with the next system on our doorstep by Tuesday. && .AVIATION /00Z Wednesday THROUGH Sunday/... Another over quiet TAF forecast with this update through the next 24 hours. The only exception will be the return of widely scattered convection developing again midday through the afternoon hours on Wednesday. The coverage will be widely scattered and once again dissipate tomorrow evening. At this time, we think the best chance for this development will be from 15z to maybe 21z. We will likely see the hit and miss convection like we had Tuesday afternoon. Otherwise, VFR condition will prevail. Winds will be gradually shift back from the south or southwest around 5 to 10 knots late tonight and tomoroww morning as a weak surface boundary lifts northward again. Outlook...Non-VFR possible with occasional showers and thunderstorms Wednesday night through the end of the week with an unsettled weather pattern. The more widespread and extensive showers, storms, and non- VFR potential will be Friday into Saturday. && .MARINE... A cold front will stall across Lake Erie tonight with northwest winds of 10 to 15 knots decreasing overnight. Conditions may be choppy for a brief period this evening with 2 to 3 foot waves before starting to decrease. A warm front accompanied by showers and thunderstorms will lift back north across Lake Erie on Wednesday. Southwest winds of 10 to 20 knots are expected on Thursday and Small Craft Advisories will likely be needed east of Cleveland. Conditions will be impacted again as this front settles back south to near Lake Erie Thursday Evening. The potential exists for thunderstorms on the lake to be strong both Thursday and Friday. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...Kahn NEAR TERM...Griffin/Kahn SHORT TERM...KEC LONG TERM...KEC AVIATION...Griffin MARINE...KEC/Sefcovic