904 FXUS61 KCLE 071402 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 1002 AM EDT Fri Oct 7 2022 .SYNOPSIS... High pressure builds in from the west across the Ohio Valley through this weekend and to the mid-Atlantic region by Monday. A weak front will cross the Great Lakes on Monday. High pressure will back in on Tuesday before a warm front lifts north across the area on Wednesday. && .NEAR TERM /THROUGH SATURDAY/... 9:30 AM Update... Only a minor update made to sky cover and PoPs for today and tonight. Slightly increased PoPs for tonight based on latest hi-res guidance and greatly increased sky cover based on latest satellite imagery and model guidance. Previous Discussion... A cold front continues through the forecast area this morning, dropping temperatures into the 50s and shifting winds to the northwest across the area. Rain and lower clouds are largely occurring behind the front, as both better moisture and lift are present and better thermodynamics are in place with some lake induced instability and moisture. Certainly will not be a wash out across the area this morning, but suspect that most of the northern counties will get a few hundredths of rain as a band of rain moves through the forecast area and have restored some higher PoPs to the forecast. As the front pulls away from the area, rain will become more scattered today and more tied to lake effect processes as cold air advection surges in with a fetch across a warm Lake Erie in the lower 60s. Therefore, have some chance PoPs for today, especially for NE OH and NW PA. Rays will be hard to come by today with lake clouds behind the front guarding the area from the sun. These clouds, along with the cold air advection regime behind the cold front, should keep temperatures down and high temperatures for the day likely already occurred at midnight, but daytime temperatures should be stagnant in the lower 50s. For tonight, clouds will start to disappear across portions of Northwest and North Central Ohio as drier air and high pressure build into the region. While the surface high will be to the west and a slight pressure gradient will be across the area to keep some light wind, conditions should be favorable enough for temperatures to drop into the lower 30s and widespread frost should develop over the western half of the area. Therefore, have issued a Freeze Watch for 2 AM to 10 AM Saturday. Frost potential decreases into Northeast Ohio and Northwest PA with clouds still off the lake and will allow another forecast cycle to determine the more conditional Frost Advisory areas for tonight. Some low level ridging and surface high pressure building in from the southwest will start to disrupt the lake effect clouds and rain tonight into Saturday, as some warmer temperatures aloft enter and mean low level flow shifts from the northwest to west. Have tapered some chance PoPs tonight for NE OH/NW PA to just slight chance for Saturday. Saturday's high temperatures could be slightly improved into the mid 50s during the day for some. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... During the short term period, high pressure will push north from the south, allowing for winds across Lake Erie to become southwest and shift any lingering lake effect rain potential out of the area. This high pressure will also bring much drier air to the region, with dewpoint temperatures dropping into the low 30s through Monday afternoon. These factors will keep the area dry through the short term period. With the shift to southwest winds, warm air advection will allow temperatures to gradually begin to climb with highs on Sunday and Monday reaching into the low to mid 60s. Overnight lows Saturday night will be in the mid to upper 30s for much of the area, but temperatures along the lakeshore will remain in the 40s. These low temperatures mixed with lighter winds may allow for areas of frost to develop. On Sunday and Monday night, temperatures will be a bit warmer with lows only dropping into the upper 30s to low 40s. && .LONG TERM /TUESDAY THROUGH THURSDAY/... The aforementioned high pressure that kept the area dry during the short term period will gradually drift off the Mid-Atlantic Coast by Tuesday night. By Wednesday morning, another trough will begin to dig south across the north-central United States. A cold front will extend along the spine of this trough and begin to gradually shift east towards the region. On Wednesday, a warm front associated with this system will shift north across the area, allowing for possible showers to develop along and ahead of the boundary. Behind this warm front, temperatures will continue to rise resulting in Wednesday's high temperatures reaching into the upper 60s to low 70s across the area. The aforementioned cold front will move across the area on Thursday, bringing plenty of moisture and widespread showers with it. As the boundary moves through temperatures will cool and only reach into the low to mid 60s on Thursday. Overnight lows temperatures will follow a similar pattern with Tuesday night being in the mid 40s to low 50s, increasing on Wednesday night into the low to mid 50s. && .AVIATION /12Z Friday THROUGH Tuesday/... With a cold front southeast of the area, rain and lower clouds have spread across the region this morning. Most terminals are MVFR although there area a few holes in the MVFR layer that have prompted brief recovery to VFR and then favored upslope areas like KMFD have had some periods of IFR. Clouds are going to hand on for a while today, especially downwind of Lake Erie and have MVFR to start for all TAF sites. Ceilings should scour out with time at KTOL and KFDY and expect these two to improve the most through the period. For KERI, once the rain ends this morning, the better MVFR chances will lie further west and have opted for just some low VFR for much of the period. For the remaining four terminals, would plan on MVFR through the period with some intermittent rain showers this morning and perhaps again this afternoon, especially at KCLE. Winds will be northwest through the period and an occasional gust to 20 kts is possible. Outlook...Non-VFR ceilings from lake clouds may linger across NE OH into NW PA into Saturday night. && .MARINE... A strong cold front moving across Lake Erie this morning has resulted in winds shifting to become north-northwest at 15-20 knots. The strong onshore flow will allow waves to build 4-6 feet through this afternoon, persisting for the central basin into the first half of tonight. As a result, a Small Craft Advisory remains in effect, but has been extended for all zones. The eastern and western basins are now in effect into the afternoon and the central basin through early tonight. As high pressure begins to push across the region tonight, winds will initially remain out of the north-northwest, but weaken to 10-15 knots. On Saturday, the aforementioned high pressure will continue to push east towards the Mid-Atlantic Coast allowing for west-southwest winds to develop across the lake. Increased pressure gradient over the lake due to a low pressure north of the region will result in winds of 15-20 knots, possibly touching 25 knots in the open waters. These conditions will persist into Sunday morning and may be the next period that would require a Small Craft. By Sunday afternoon, high pressure will push north across the lake, weakening the pressure gradient and allowing west winds of 5-10 knots to occur through Monday. Waterspouts should not be a problem through the weekend as strong winds, lack of moisture, and less than optimal delta-T between the lake and 850mb should prevent any development. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...Freeze Watch from late tonight through Saturday morning for OHZ003-006-008-017>019-027>030-036-037-047. PA...None. MARINE...Small Craft Advisory until 3 PM EDT this afternoon for LEZ142>144-148-149. Small Craft Advisory until 2 AM EDT Saturday for LEZ145>147. && $$ SYNOPSIS...Saunders NEAR TERM...Saunders/Sefcovic SHORT TERM...Campbell LONG TERM...Campbell AVIATION...Sefcovic MARINE...Campbell