425 FXUS61 KCLE 130806 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 406 AM EDT Tue Aug 13 2019 .SYNOPSIS... Low pressure over Indiana will move southeast to the upper Ohio valley today. A weak cold front will sink south across the area tonight. A weak low will drop southeast into the southern Great Lakes Wednesday into Wednesday night, and will slowly work east across the region through Thursday night. && .NEAR TERM /THROUGH WEDNESDAY/... Low pressure will generally weaken as it tracks east southeast across Ohio this morning, with the low center passing just south of the forecast area. The focus of the best forcing will remain south of the low track this morning, with the latest radar trends showing weakening precipitation immediately upstream of the forecast area, as 700mb convergences weakens and upstream moisture focuses into the southern half of Ohio. Have kept likely pops for shower activity moving across the area through the morning, but kept thunder in the slight chance/chance range with little instability to work with and little/no upstream lightning being observed. The surface low will pass southeast of the area through the day, with a secondary surface cold front working south into the forecast area. This, combined with weak diurnal recovery and a mid level speed max passing across the southern part of the area, warrants continued shower/t-storm chances midday through this afternoon, with the focus of the activity shifting south of the area this evening. Have pops generally trending downward through midnight, with dry conditions moving into the area overnight. Highs today will be in the mid 70s to low 80s, with lows tonight in the low to mid 60s. A shortwave will dig southeast into southern Great Lakes Wednesday, with precip chances increasing from the west through the afternoon. Went with pops increasing to slight chance midday, then a brief period of chance pops west of the I-75 corridor. The aforementioned cold front will wash out across the southern part of the area, but enough moisture pooling and weak convergence may linger across the south late afternoon, so went with slight chance pops for this area. Models showing some weak instability recovering into the area, so have kept at least a slight chance thunder mention. Highs will be in the upper 70s/low 80s. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... High pressure will be located over eastern Ontario into Quebec Wednesday night which should nudge the frontal boundary south and west of the area. Cant completely rule out a showers across NW Ohio but confidence in this will be low with a drier northeast wind anticipated. The front will drift back to the north on THursday as another upper level trough moves across the Great Lakes. Not all that much moisture to work with so having a hard time going higher than chance POP's at this time. This ripple of low pressure should move east of the region by Friday morning with only some sprinkles or isolated showers lingering into the afternoon. All locations should be dry Friday night. Highs in the short term will mostly be in the mid 70s to around 80. Lows in the mid 50s to lower 60s. && .LONG TERM /SATURDAY THROUGH MONDAY/... Lots of uncertainty in the long term with models hinting at several weak pieces of jet energy impacting the region. Timing in each of the long term models is different so confidence is extremely low with our POP's. Have kept slight chance to chance POP's over the weekend and will adjust as the models focus in on a solution. Definitely does not look like a washout Saturday or Sunday but there will be a few showers/thunderstorms across the region. High pressure should build into the area Sunday night into Monday. Temperatures look as if they will be above seasonal averages Saturday through Monday unless cloud cover ends up being thicker than anticipated. && .AVIATION /06Z Tuesday THROUGH Saturday/... Low pressure tracking east through the area today will bring scattered showers and low MVFR to possible IFR conditions at times. Thunder chances have been lowered vs. previous forecasts, with the best chances for TSRA are early at KFDY and this afternoon/evening at KMFD, KCAK and KYNG. Conditions improve late in the period with ceilings lifting and scattering at most site. Winds will be variable with the passage of the low, but northwest to northerly behind the low late. OUTLOOK...Non-VFR possible late Thursday into Friday with showers and thunderstorms. && .MARINE... Weakening area of low pressure will track near or just south of the lake through this evening. High pressure will then ridge into the area from the upper Great Lakes region with northeasterly winds developing tonight. Winds appear they will be in the 10 to 15 knot range into Thursday. The longer fetch will likely build waves to at least 2 to 4 feet. We will need to monitor for the possibility of a brief small craft advisory from Geneva on the Lake to the Islands Wednesday night into early Thursday. A weak trough will cross the central Great Lakes Thursday night into Friday with light easterly winds swinging around to the north in its wake. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...Greenawalt NEAR TERM...Greenawalt SHORT TERM...MM LONG TERM...MM AVIATION...Greenawalt MARINE...MM