Marine Weather and Tide Forecast for Vermilion, OH

NEAR TERM /THROUGH SUNDAY NIGHT/
630 PM EST Update...
The forecast remains on track and no changes were needed with this update. It will become quite breezy tonight with southwest sustained winds to 25 mph likely. While periodic gusts to 40 mph may mix to the surface tonight as a 50-60 knot LLJ settled over the region, the boundary layer will most likely remain decoupled so do not anticipate frequent stronger gusts at this time. A few showers may clip NW PA tonight, but the lower levels will likely stay too dry for any appreciable precipitation to reach the surface.

Previous Discussion...
Quieter weather prevailing into this evening with the lake effect shut down at this point. Remaining tranquil through the overnight period with the exception of a weak surface/low level thermal trough clipping the far northeast zones in NW PA/NE OH.
Throw some slights back in the mix and some low level cloud cover representing this feature, but POPless again after 15Z Sunday for the bulk of that day. Meanwhile, split flow regime aloft in place with two upper level lows moving eastward into the plains. The southern stream trough axis pushes into the Ohio Valley with a warm front into the region introducing the beginnings of a milder regime across the CWA Antecedent upper level ridging already has temperature improvements for Sunday which will become enhanced by the warm frontal passage Sunday night and heading into the short term forecast period. Saturated isentropic lift with the warm front brings stratiform rain in from the southwest Sunday night with rain overspreading the entire CWA and pushing eastward by 12Z Monday. Looking at a quarter to half inch in the southwestern zones of the CWA by the break point with the short term forecast period 12Z Monday.

SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/
An active and mild short term period is in store across the region as temperatures rebound to above average in the upper 40s to lower 50s. Widespread rain is expected on Monday, particularly in the morning, resulting from broad isentropic lift associated with a weak mid-level wave moving northeast across the Ohio Valley. Although rainfall amounts appear to be generally on the lighter side, there is a subtle signal of totals nearing 0.50 inches across Northeast Ohio and Northwest Pennsylvania with modest dew points in the 40s expected. Recent NOHRSC analysis reveals snow water equivalent in excess of 4 inches across portions of the snowbelt, resulting from the recent historic lake effect snows. Confidence is low for any significant flooding, but certainly can't rule out areas of minor flooding where significant snowpack currently exists.

A more potent upper-level trough will move east across the central and eastern CONUS Monday night through Tuesday, with more rain possible Tuesday afternoon into Tuesday night, particularly along and east of the I-71 corridor. A strong cold front will accompany this system Tuesday night, ushering in another blast of arctic air into the region.

LONG TERM /WEDNESDAY THROUGH SATURDAY/
Confidence is increasing for accumulating lake effect snow once again across the primary snowbelt Wednesday night through Thursday as another blast of arctic air descends across the Great Lakes.
Confidence is high for 850 mb temperatures to reach at least -15 degrees C on Thursday, with some ensemble members even suggesting low probabilities of 850 mb temperatures reaching as low as -20 degrees C. Boundary layer winds will largely mimic the Thanksgiving lake effect event, with W to SW winds expected and minimal directional shear present. A lake aggregate trough should largely limit accumulations outside of the primary snowbelt, with initial indicators suggesting the lakeshore areas will see the highest snowfall once again. Thursday will be the coldest day of the long term period with highs in the low to mid-20s in addition to single digit to near-zero wind chills likely. Recent LREF guidance does show low (30%) probabilities of sub-zero wind chills Thursday morning so will be something to monitor.

A ridge will begin to build in from the central CONUS by late Friday into Saturday, signaling an end to any lingering lake effect snow across the region. Temperatures will rebound back to the upper 30s to lower 40s on Saturday.

AVIATION /00Z Sunday THROUGH Thursday/
Main concern during the TAF period will be LLWS and breezy southwest winds tonight into early Sunday. Expect southwest sustained winds to 20 knots tonight before gradually diminishing early Sunday morning into the afternoon. A 50-60 knot LLJ will be overhead through Sunday morning, but the boundary layer will likely remain decoupled so currently thinking that any gusts will be infrequent. As a result, all local TAFs have LLWS with southwest 2000ft AGL winds to 55 knots until mixing begins to kick in at about 12Z Sunday morning. If decoupling doesn't occur as expected, there could be periodic gusts to 30 to 35 knots at inland terminals through 06Z and lakeshore terminals through about 12Z. Gusts will be around 20 knots after sunrise Sunday morning before diminishing during the afternoon. Will continue to monitor wind gusts and make amendments as needed.

Generally expect VFR at most terminals through the TAF period, although ceilings will begin to lower at KCLE/KYNG/KERI Sunday afternoon as low pressure passes to the north of Lake Erie. MVFR ceilings are likely at KERI after 18Z or so.

Outlook...Non-VFR expected Sunday night through Tuesday in rain.
More non-VFR expected in post cold frontal snow/lake effect snow in Northeast Ohio and Northwest Pennsylvania Wednesday and Thursday.

MARINE
Marine conditions will continue to deteriorate this evening and overnight, with southwest Gales to 35 knots developing across the central and eastern basins of Lake Erie. Winds will occasionally gust in the 40 to 45 knot range into Sunday morning, with isolated higher gusts of 50 knots possible in the open waters. Winds will briefly shift towards the west Sunday morning, decreasing to around 20 knots by Sunday afternoon, then to 10 knots or less out of the south by Sunday evening. Relatively quieter marine conditions will then persist on Monday into Tuesday with southwest flow around 10 to 15 knots. A cold front will cross the lake late Tuesday, with a secondary and more potent cold front expected to arrive on Wednesday.

A Low Water Advisory also remains in effect as persistent southwest winds will result in water levels across the western basin of Lake Erie falling below the critical mark for safe navigation of 2 inches below low water datum. There is a modest potential (around 50%) for water levels to reach as low as 12 inches below low water datum late tonight into Sunday morning.

CLE WATCHES/WARNINGS/ADVISORIES
OH...None.
PA...None.
MARINE...Small Craft Advisory until 10 AM EST Sunday for LEZ142>144.
Low Water Advisory until 10 AM EST Sunday for LEZ142>144- 162>164.
Small Craft Advisory until 4 PM EST Sunday for LEZ145-146.
Gale Warning until 7 AM EST Sunday for LEZ147>149-166>169.