Marine Weather and Tide Forecast for Oak Harbor, OH

NEAR TERM /THROUGH SUNDAY/
Aloft, WSW'erly flow over our CWA today becomes W'erly tonight as a shortwave trough moves E'ward from the northern Great Plains toward the Gulf of Saint Lawrence region and a shortwave ridge shifts E'ward behind the shortwave trough. At the surface, the shortwave trough's attendant low moves NE'ward from Lake Huron toward Newfoundland through daybreak Sunday.
This low track will allow the trailing cold front to sweep SE'ward through our CWA late this morning through late afternoon. Behind the cold front, the ridge builds into our CWA through daybreak Sunday as the embedded surface high pressure center moves from the north-central United States toward the northern Great Lakes. A few peeks of sunshine and continued low-level WAA ahead of the cold front should allow daytime highs to reach the mid 60's to mid 70's. A SE'ward gradient in high temperatures is forecast today. Low-level CAA and partial clearing behind the cold front will allow lows to reach the mid 30's to lower 40's in NW PA and the upper 30's to upper 40's in northern OH around daybreak Sunday.

Isolated to scattered showers and thunderstorms should increase in coverage from WSW to ENE the rest of this morning through midday due to the following reasons:

1.) A SW'erly low-level jet ahead of the cold front results in enhanced moist isentropic ascent just aloft, which will release weak to perhaps moderate elevated CAPE.

2.) Low-level convergence and moist ascent along the cold front, which will release weak to perhaps moderate surface-based and elevated CAPE as continued low-level warm/moist air advection from the Gulf and limited daytime heating later today allow an initially elevated effective inflow layer to become surface-based within the warm sector.

3.) Moist isentropic ascent along the upper-reaches of the cold front, which is expected to release weak and elevated CAPE.

Shower/thunderstorm potential will end gradually from NW to SE this afternoon through the wee hours of Sunday morning as the cold front, including its upper-reaches, exits to the SE and stabilizing subsidence accompanies the aforementioned ridge.
Thus, fair weather is then expected through daybreak Sunday, in the wake of the convection. Moderate to strong effective bulk shear will allow convection to be organized. WSW'erly mean mid- level flow with a large component parallel to the cold front will allow showers/thunderstorms to train along the front.
Despite the expectation of unusually-high PWAT values allowing showers/storms to produce periods of torrential rainfall, fast mean mid-level flow will result in fast shower/storm motions and greatly curb the potential for flooding. The latest SPC convective WX outlook highlights a marginal risk of severe thunderstorms from roughly Wattsburg, PA to Upper Sandusky, OH and points toward the SE. Confidence in severe thunderstorm occurrence late this morning through afternoon is low. However, some model soundings indicate weak to moderate boundary layer CAPE amidst a surface-based effective inflow layer, steepening mid-level lapse rates/MUCAPE growing to near 400 J/kg in the hail growth zone, and atmospheric melting levels near 10kft AGL may allow a few storms to produce hail up to the size of quarters. Steepening low-level lapse rates/DCAPE increasing to near 500 to 750 J/kg may allow a few thunderstorms to produce straight-line convective wind damage.

Fair weather is expected on Sunday as stabilizing subsidence accompanies the aforementioned ridge. The shortwave ridge aloft will crest E'ward across our region as the surface portion of the ridge eventually exits slowly E'ward in response to the embedded high pressure center moving from the northern Great Lakes toward the Upper Saint Lawrence River Valley. The anticyclonic circulation of the surface ridge will allow N'erly to E'erly surface winds to transport cooler/drier air into our region. However, peeks of sunshine will permit some daytime heating. Late afternoon highs are expected to reach the 50's north of roughly the U.S. 30 corridor and the upper 50's to upper 60's elsewhere in our CWA

SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/
Sunday night should start dry across the region with high pressure to the northeast and the front remaining south of the forecast area.
Unfortunately, a low pressure system will develop over the central CONUS and allow this front to lift north as a warm front for Sunday night into Monday. Rain chances will be on the rise with this feature and temperatures will be trending upward into the 70s for Monday ahead of the cold front. A cold front will move across the forecast area on Monday and bring a round of showers with some thunderstorms across the region. While there will be some instability ahead of the front for storms, believe that there won't be any organized convection with less favorable shear. Have PoPs decreasing for Monday night with the frontal passage. High pressure will be quick to build in for Tuesday and will maintain a dry forecast with highs in the 60s.

LONG TERM /WEDNESDAY THROUGH FRIDAY/
High pressure should remain influential across the region on Wednesday despite moving east and out of the area. Weather conditions should remain dry and a warm front will lift north on the back side of the high and allow for temperatures to rebound to mostly in the 70s. For Thursday, the forecast remains rather uncertain with the potential for rain. Some mid-level energy will undercut an upper ridge and there will be some better moisture across the region with dew points up to the mid 50s. However, there isn't much clarity on what may force rain, as the main front should remain northwest of the local area and the next low pressure system will be slow and should largely be a Friday problem. Therefore, will opt for low PoPs on Thursday. For Friday, a low pressure system will lift northeast into the region and allow for rain to overspread the area. This system will then allow for a cold front to move through the region but the precise timing of this late week system remains uncertain and there could still be rain impacts into Saturday.
Therefore, will just ramp up PoPs through the end of the week.



AVIATION /06Z Saturday THROUGH Wednesday/
Aloft, WSW'erly to W'erly flow persists over our region through 06Z/Sun as a disturbance moves E'ward from the north-central United States to QC and vicinity and a ridge builds E'ward behind the disturbance. At the surface, the attendant surface low moves NE'ward from near Lake Huron to near the Gulf of St.
Lawrence through 06Z/Sun. The low track will allow the trailing cold front to sweep SE'ward across our region between ~14Z/Sat and ~20Z/Sat. Behind the front, a ridge builds from the north- central United States through 06Z/Sun.

The cold front passage will cause our regional surface winds to veer from SW'erly to NW'erly. The SW'erly winds are expected to be near 10 to 15 knots and gust up to 20 to 25 knots at times.
NW'erly winds behind the front will be around 5 to 10 knots and veer gradually toward N'erly in response to the aforementioned ridge. Widespread low/mid-level clouds and VFR ceilings are expected ahead of the cold front. Behind the cold front, widespread low clouds and associated MVFR to VFR ceilings are expected through 06Z/Sun. These ceilings should primarily be in the range of 1kft to 5kft AGL.

A strengthening SW'erly low-level jet ahead of the cold front and the front itself should allow isolated to scattered showers/thunderstorms to overspread our region generally from WSW to ENE through 14Z/Sat. Shower/thunderstorm coverage is expected to increase gradually during that time period. As the cold front sweeps SE'ward through our region, showers and thunderstorms should end gradually from NW to SE between ~21Z/Sat and ~02Z/Sun. Brief IFR and brief/erratic surface wind gusts up to 30 to 40 knots are possible with showers and especially thunderstorms. Note: Since SW'erly surface winds will be fairly well-aligned with the SW'erly low-level jet, low-level turbulence rather than true LLWS is expected.

Outlook...Scattered rain showers with non-VFR expected on Sunday through Monday evening. Scattered thunderstorms are possible overnight Sunday night through Monday evening.

MARINE
Elevated southwest winds remain over Lake Erie this morning ahead of a cold front. The boundary layer has stabilized enough to keep the gusts at bay, but the representative surface observations remain with 15 to 20 kts sustained with some of the higher elevated marine obs coming in a bit stronger. A cold front will move across the lake by this afternoon and winds will shift more westerly and decrease.
There will be some fog over the lake with the cold frontal passage, given the warmer temperatures and higher moisture content ahead of this feature. With the westerly winds, waves will build slightly for the nearshore waters, but should remain below any headline criteria.
The front will slouch all of the way south to the Ohio River and northerly flow will take over tonight. For Sunday, low pressure to the west will lift this front north as a warm front and winds will flip to the east and eventually to the south for Monday. The low will pass to the northwest for Monday and extend a cold front across the lake. Southwest flow will increase ahead of the front and there could be a need for a brief Small Craft Advisory headline. Winds will become westerly behind the front for Monday night into Tuesday and waves could build up slightly for the eastern half of the lake.
High pressure will build into the region for Tuesday and Wednesday and flow will be 10 kts or less and be variable through the middle of the week.

CLE WATCHES/WARNINGS/ADVISORIES
OH...None.
PA...None.
MARINE...None.