582 FXUS61 KCLE 170805 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 405 AM EDT Wed Mar 17 2021 .SYNOPSIS... A weak high pressure ridge over the Great Lakes region this morning will move eastward later today. A developing low pressure system near the near Oklahoma will move towards the Ozarks Region later today. This stronger low pressure system will then track towards to the Mid- Atlantic region on Thursday and east of New Jersey by Friday morning. Behind this low, a stronger ridge affects our region Friday through weekend as the embedded high moves from near James Bay to the Mid- Atlantic region. && .NEAR TERM /THROUGH THURSDAY/... The main weather story in the near term will be the storm system bringing gusty winds and widespread rain on Thursday. We have weak high pressure in control of our weather pattern this morning with light winds and mostly clear to fair skies. Due to these calm and clear conditions, we do have some patchy fog mainly down near the higher terrain around Mansfield back to the west towards the Findlay area. The latest nighttime microphysics satellite imagery is showing some patchy fog developing west-southwest of the Cleveland metro area as well. While there may be some patchy dense fog this morning, we are not expecting the fog to become widespread. The patchy fog does appear to be shallow in nature. We should see a good amount of sunshine this morning and that will quickly burn off any fog shortly after sunrise. High and mid level clouds will be on the increase from the west and southwest later this afternoon into this evening. Temperatures will be milder today with lower to middle 60s expected away from the lakeshore and cooler in the 50s closer to the lake. A rather stout and strong low pressure system will be developing near the Ozarks Region later today into tonight. This low pressure system will deepen as it track eastward across the lower Ohio Valley on Thursday. The pressure gradient between this low and a high pressure system north of the Great Lakes region will cause northeast winds to increase late tonight into Thursday. Gusty winds up to 35 to 45 mph may be possible with the highest wind gusts near the lakeshore and west of I-71. Widespread light to occasionally moderate rain will advance in our direction ahead of this system and spread across the region tonight through Thursday. Tomorrow will be wet and blustery day with temperatures only in the 40s. General rainfall amounts expected with this system will average .75" across northwest PA to 1.25" near our central Ohio counties with isolated higher amounts possible. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... By Thursday night, the event will likely be winding down with rain changing to a rain/snow mix, then eventually all snow by early Friday morning as colder air aloft moves into the region. However, as anomalously high pressure moves south across the Great Lakes and the low exits east of the area, a substantial pressure gradient should remain in place over the region, especially west of I-71 and along the lakeshore. We could easily see gusts of 40 to 45 mph, or higher to near 50 mph along the immediate lakeshore, with sustained winds of 25 to 30 mph. It shouldn't take much to see these type of winds given the corridor of 50 to 60 knot 925 mb winds across the area. Will likely need at least Wind Advisory headlines during this period. Winds will continue decreasing in intensity throughout the day Friday, though some gusts of 25 to 30 mph remain possible. Skies should clear relatively fast Friday morning, making for a sunny, yet chilly and blustery day with highs in the lower 40s. Lows Friday night will reach the low to mid 20s under clear skies. By Saturday, sunny skies will remain, albeit with slightly warmer temperatures with highs generally in the low to mid 50s. Given the light flow across the region, anticipate lake breeze development is possible. This would result in slightly cooler temperatures in the mid to upper 40s along the lakeshore. && .LONG TERM /SUNDAY THROUGH TUESDAY/... A quiet long term period is expected as high pressure builds southeast through the Great Lakes to the Atlantic coast through Tuesday. Low pressure will approach the area on Tuesday, but most of the precipitation should hold off until just after the forecast period. Above average temperatures are expected through the long term period with plentiful sunshine on Sunday and Monday. For now, went with 50 percentile NBM temperatures which brings highs in the lower to mid 60s on Sunday, with mid to upper 60s on Monday. Will have to watch for lake breeze development Clouds begin increasing from the west on Tuesday, though warm air advection will keep temperatures well above average into the mid 60s. && .AVIATION /06Z Wednesday THROUGH Sunday/... VFR conditions are present across much of the airspace this overnight. The only aviation issue we are watching this morning is some localized fog around FDY bringing down the visibility to less than 1 sm and at times patchy dense along with some broken ceilings around 700 feet. The other areas are around MFD and CAK with some MVFR ceilings from time to time around 2500 feet. Any localized fog and low ceilings will give way to all airspace seeing VFR conditions by mid to late morning and continuing through this TAF period. High and mid level clouds will increase late in the TAF period with rain becoming likely just beyond this time window. Winds will be somewhat light and variable but eventually becoming northeasterly later in the period between 5 and 10 knots. ERI may see a light lake breeze from early to mid afternoon and briefly shift the wind from the north around 5 knots. Outlook...Non-VFR are likely with widespread periods of rain late Wednesday night through Thursday night. Rain may mix with or change to snow before precip ends overnight Thursday night. && .MARINE... Have issued a Gale Watch for much of the lake, excluding the open waters on the far eastern basin from Thursday morning through early Friday morning. Northeasterly winds will increase on Thursday morning, reaching 25 to 30 knots with gusts near 40 knots. By Thursday afternoon, northeasterly winds will increase further, reaching sustained winds of 35 knots or higher with gusts inching towards 50 knots. Northeasterly winds will begin slowly decreasing Friday morning into the 20 to 25 knot range with lighter flow returning across the lake by Friday evening. Light flow across the lake will persist through Tuesday with high pressure in place. In addition to the Gale Watch, there is potential for lakeshore flooding headlines across the central and western basin of the lake. Have opted not to issue a lakeshore flood watch at this time given a relatively low water level forecast, but given the prolonged northeasterly flow across the lake, potential for one is certainly there. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...Gale Watch from Thursday morning through late Thursday night for LEZ142>146-162>166. Gale Watch from Thursday morning through late Thursday night for LEZ147>149-167>169. && $$ SYNOPSIS...Griffin NEAR TERM...Griffin SHORT TERM...Kahn LONG TERM...Kahn AVIATION...Griffin MARINE...Kahn