957 FXUS61 KCLE 300211 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 1011 PM EDT Fri Sep 29 2023 .SYNOPSIS... Upper level low pressure moves east of the region through this evening. High pressure then builds over the area for this weekend and persists into next week. && .NEAR TERM /THROUGH SATURDAY NIGHT/... Clouds have mostly cleared across the area and starting to see visibilities fluctuate at a few locations with LPR down to 3/4 mile at 10 PM and TTF(Monroe Michigan) at 1/4 mile with several sites in Indiana also starting to drop. Have expanded the fog wording a bit in the forecast with areas of dense fog expected across portions of NW Ohio and at least patchy fog possible everywhere. Will hold off on any headlines until we see fog expand but conditions remain favorable with clear skies, light winds, and fairly high boundary layer moisture. Confidence is highest along the western lakeshore and towards TOL where some convergence off Lake Erie is expected. Previous discussion... Generally improving conditions through the end of the week and into the weekend as the upper low continues to exit east. Mid/upper ridging and surface high pressure will build in over the region to begin the weekend. Lingering low level moisture, small dew point depressions, and light/variable winds tonight all support patchy fog development across much of the western half of the forecast area. Any fog that forms will be patchy and eventually lift by Saturday morning as dry air and high pressure continue to enter from the west. As the high builds overhead, expect for cloud cover to gradually dissipate on Saturday and give way to mostly sunny skies this weekend. Overnight lows will settle in the mid 50s areawide both tonight and Saturday night. Afternoon highs on Saturday will rise a few degrees above normal for the end of September, reaching the mid 70s for most. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... A large upper level ridge will dominate our weather pattern for this weekend into next week. The center of this upper level ridge will be near the Lower Ohio Valley on Sunday. At the surface, there will be a high pressure system located near the eastern Great Lakes region on Sunday. Plenty of sunshine and mostly clear skies are in the forecast for this weekend into early next week with quiet weather. High temperatures Sunday afternoon will top out in the middle 70s to near 80 degrees. The center of the upper level ridge moves slightly eastward by Monday but firmly in place over the Ohio Valley region. Monday's afternoon high temperatures will be in the upper 70s to lower 80s. && .LONG TERM /TUESDAY THROUGH FRIDAY/... The upper level ridge will slowly shift eastward on Tuesday and be centered right over the Upper Ohio Valley region. Tuesday afternoon may be our warmest day of this forecast period with temps reaching the lower 80s. There could be a few spots that get into the middle 80s over northwest Ohio on Tuesday. The ridge begins to shift further eastward as well as the surface high pressure by Wednesday. A sharp upper level trough will develop across the north central CONUS by mid week as well. The upper level trough will continue to dig across the central CONUS and into the Midwest on Thursday with a cold front sliding into the Ohio Valley region from the west late in the day. We will remain above average ahead of that frontal passage through Thursday. Scattered rain chances will late on Thursday as the cold front approaches from the west. && .AVIATION /00Z Saturday THROUGH Wednesday/... VFR conditions are in place at all terminals at the start of the period. Most inland sites and especially locations in NW Ohio can expect deteriorating conditions through the overnight. There is a favorable set-up for fog again tonight as boundary layer moisture remains high with nearly calm winds and clear skies. Chances for fog are highest at TOL/FDY with some light northeast flow component off Lake Erie but could also see fog at MFD/CAK/YNG. Brought these terminals down to IFR and will have to monitor the extent of low visibilities with less support in the model data at these locations. CLE could also experience a period of MVFR to IFR if winds go calm while ERI should maintain enough of a drainage flow to prevent fog. If fog becomes widespread, expect a 100-200 foot ceiling to be a little slower to lift and scatter out in the morning. Otherwise the trend will be towards clouds lifting and scattering through the morning on Saturday. Nearly calm winds overnight will return out of the east or northeast at less than 10 knots by midday on Saturday. Outlook...Non-VFR possible in low ceilings and patchy dense fog Saturday and Sunday mornings. && .MARINE... The weather will be very quiet on the lake this weekend through the middle of next week with high pressure in control. Winds will be from the east or northeast this weekend 5 to 10 knots and waves up to 1 foot. By Sunday night into Monday, winds will become southeasterly 5 to 10 knots with waves up to 1 foot. These relatively calm conditions will last through midweek. Marine headlines are anticipated this weekend through the middle of next week. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...Iverson NEAR TERM...KEC/Iverson SHORT TERM...Griffin LONG TERM...Griffin AVIATION...KEC MARINE...Griffin