Marine Weather and Tide Forecast for Euclid, OH

KEY MESSAGES
1.) A strong cold front continues to sweep eastward through our region through this early evening. There is limited potential for isolated severe thunderstorms ahead of the front, especially east of roughly I-77.

2.) Unusually-cold air temperatures follow the strong cold front through this Monday night. Frost and sub-32F low temperatures are a concern. In addition, accumulating lake-effect snow is a concern overnight Sunday night into Monday morning.

DISCUSSION
KEY MESSAGE 1...
Aloft, SW'erly flow and embedded shortwave disturbances affect our region through daybreak Sunday as a primary trough axis moves from the Upper Midwest toward the western Great Lakes. At the surface, a strong cold front extended from just west of the Lake Erie Islands to near Arlington, OH at 2:55 PM EDT this afternoon.
This front will continue moving E'ward and should exit the rest of our CWA by 7 PM this evening. Low-level convergence/moist ascent along the surface cold front and pre-front surface trough axes in the warm sector, tied to the shortwave disturbances aloft, will continue to release primarily weak MUCAPE amidst a surface-based effective inflow layer, moderate to strong effective bulk shear, and steep low-level lapse rates/DCAPE as large as 400 to 600 J/kg, and result in scattered multicell rain showers and isolated multicell and supercell thunderstorms capable of producing strong to damaging straight-line convective wind gusts as strong as 40 to 60 mph.
The best potential for isolated straight-line convective wind damage exists roughly along/east of I-77, where greater daytime heating has resulted in steeper low-level lapse rates and greater DCAPE and boundary layer CAPE, respectively. Once the surface cold front passes, isolated to scattered rain showers associated with moist isentropic ascent along the upper-reaches of the front should exit our CWA generally from west to east between about 6 PM this evening and 5 AM tomorrow. Partial to considerable clearing is expected behind the front as stabilizing subsidence accompanies a surface ridge that will attempt to build from the northern and central Great Plains.
This clearing and low-level cold/dry air advection behind the front will allow low temperatures to reach the mid 30's to lower 40's around daybreak Sunday. Sufficient easing of surface winds should contribute to areas of frost formation around daybreak in interior Lucas County and far-northern Wood County.

KEY MESSAGE 2...
On Sunday through Sunday night, flow aloft eventually veers from SW'erly to NW'erly as the primary trough axis aloft moves from the western Great Lakes to near central NY and central PA and shortwave troughs embedded in the flow continue to impact our region. Flow aloft then remains NW'erly through Monday night as a ridge aloft builds from the west. At the surface, net troughing should linger over northern OH and NW PA, and a secondary cold front should sweep SSE'ward through our CWA Sunday evening. Behind the front, the aforementioned surface ridge should begin to build in earnest from the northern and central Great Plains through daybreak Monday. During the remainder of Monday through Monday night, the surface ridge should eventually crest E'ward in our region as the ridge aloft continues to build from the west. This weather pattern evolution at the surface and aloft will maintain a net low-level CAA regime and unusually-cold air temperatures in our area.
Late afternoon highs should reach only the lower 40's to lower 50's on Sunday. Overnight lows should reach mainly the lower 20's to lower 30's around daybreak Monday and prompt the eventual upgrade of the Freeze Watch to a warning for our CWA
On Monday, late afternoon highs should reach only the mid 30's to upper 40's as colder air continues to overspread our region generally from the northwest, behind the secondary cold front.
Overall clearing and easing of our regional surface winds Monday evening through daybreak Tuesday should contribute to significant radiational cooling and lows reaching the 20's to mid 30's. Additional freeze and frost alerts will likely be needed.

Periods of rain are expected Sunday afternoon through evening in response to moist isentropic ascent aloft, ahead of a shortwave trough axis, low-level convergence/sufficiently- moist ascent along the secondary cold front, and eventual development of lake-effect precip (LEP) over and generally southeast of Lake Erie, behind the cold front. Continued CAA at the surface and aloft and the wet-bulb effect should allow rain to mix with or change to wet snow Sunday evening, especially in NE OH and NW PA. Any snow accumulations by midnight should be a half inch or less and confined to the higher terrain in NW PA and far-NE OH. Additional LEP, mainly in the form of snow, is expected over and generally southeast of central and eastern Lake Erie Monday morning as a NW'erly mean low-level flow of unusually-cold/sufficiently-moist air persists over/downwind of the ~8C to ~10C lake. The most-persistent snow, steady to heavy at times, should be focused across Ashtabula County, western Erie and Crawford Counties, PA, and vicinity due to an upstream moisture connection to Lake Huron and resulting corridor of greater lake-induced CAPE over Lake Erie. This is where additional snow accumulations of 1-3" are possible. Additional snow accumulations elsewhere in our snow belt counties and vicinity should be 1" or less. LEP should weaken considerably and then end by early Monday afternoon, and then be followed by dry weather region-wide through daybreak Tuesday as the aforementioned ridge is accompanied by a lowering and stabilizing subsidence inversion. Note: an overall warming trend is expected in our CWA on Tuesday through Saturday due, in part to our region becoming located within a net WAA regime along the western flank of the ridge at the surface and aloft. More details to come in future AFD's.

AVIATION /18Z Saturday THROUGH Thursday/
A band of showers is working eastward across all terminals this afternoon. This will bring periods of MVFR, with some IFR possible at KCAK and KYNG late this afternoon and early evening, but not confident enough to put IFR in the TAFs. Some thunder is possible on the front edge of this band. This is mostly likely at KCAK, KYNG, and KERI. The threat of severe thunderstorms has significantly diminished.

The showers will exit from west to east this evening, with all rain expected to be out of far eastern Ohio and western PA terminals by 03Z at the latest. This will lead to skies becoming VFR for tonight. VFR will continue Sunday morning before additional rain showers accompany a trough Sunday afternoon.

Winds will turn W to WNW behind a cold front late this afternoon and evening averaging 15-20 knots with gusts of 20-30 knots.
WNW winds will continue overnight gradually decreasing to 5-15 knots before increasing to 15-25 knots again Sunday morning.

Outlook...Non-VFR possible in scattered rain and snow showers Sunday afternoon and early Sunday night. Non-VFR possible Tuesday night and Wednesday in rain showers.

MARINE
Winds will increase behind a strong cold front this evening, with WNW winds of 15-25 knots in the western basin. These winds will persist in the western basin through about 06Z before diminishing to 10-20 knots. This lull in stronger winds will continue through mid Sunday morning before WNW winds increase to 15-25 knots across the entire lake from late morning through the afternoon. Issued a Small Craft Advisory from Reno Beach to Willowick starting at 00Z this evening to capture the first period of stronger winds, but after coordination with WFO Detroit, decided to delay the start of the Small Craft Advisory from Maumee Bay to Reno Beach until 14Z Sunday since the winds Sunday are more of a slam dunk. Small Craft Advisories also begin for the rest of the nearshore waters from Willowick to Ripley after 14Z Sunday. WNW winds of 15-25 knots will continue through the afternoon, building wave heights to 3-5 feet at times, before winds diminish Sunday evening. It will take until early Sunday night for winds to diminish in the western and central basins, so that Small Craft Advisory runs the longest (through 03Z Monday).

Light winds are expected Monday and Monday night as high pressure builds across the Great Lakes before S winds increase to 15-20 knots Tuesday ahead of another cold front. Light winds will return Wednesday through Thursday as another high builds across the Great Lakes.

CLE WATCHES/WARNINGS/ADVISORIES
OH...Frost Advisory from 2 AM to 10 AM EDT Sunday for OHZ003-006.
Freeze Watch from Sunday evening through Monday morning for OHZ003-006>014-017>023-027>033-036>038-047-089.
PA...Freeze Watch from Sunday evening through Monday morning for PAZ001>003.
MARINE...Small Craft Advisory from 10 AM to 8 PM EDT Sunday for LEZ142- 147.
Small Craft Advisory from 8 PM this evening to 11 PM EDT Sunday for LEZ143>146.
Small Craft Advisory from noon to 8 PM EDT Sunday for LEZ148- 149.