Marine Weather and Tide Forecast for Sheffield Lake, OH

NEAR TERM /THROUGH SUNDAY/
910 AM Update...
No major changes to the forecast this morning. Still below freezing across the area, but should see upper 30s for most today, except for lower to mid 30s in NW PA.

Previous Discussion...
Lake effect snow has largely ended other than a few flurries in Erie, PA, so have cancelled the lake effect snow warning.

A weak low passes to the north across the northern Great Lakes region, with minor isentropic lift possibly leading to light snow for parts of Northwest Pennsylvania this afternoon to right around sunset. Shouldn't see any accumulation, especially since most models have been trending towards this precipitation largely staying to the east. Modest pressure gradient and a strong low-level jet overhead (50-60 kts at 850mb) will lead to breezy conditions later this evening into the overnight hours, especially near the lakeshore. A few models, such as the HRRR, suggest that we could get close to wind advisory criteria near the lakeshore and especially the Erie, PA lakeshore. HRRR soundings show a decent temperature inversion which should prevent too much mixing of winds aloft. Nevertheless, we'll have to keep an eye on this to see if a headline is needed.

By Sunday this system departs to the east. The surface high pressure located to the south also moves off the Atlantic coast.
Southwest flow should lead to rising temperatures with highs ranging in the upper 40s across Northwest Ohio to around 40 in Northwest Pennsylvania.

SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/
A big thaw is still expected to start the week, but the pattern will remain very active.

A strong mid/upper trough will dive into the Rockies and Plains Sunday night and Monday, with an associated surface low slowly progressing from North Dakota Sunday night to Lake Superior by late Monday. This low will weaken as it drifts northeastward into the vicinity of Hudson Bay Tuesday and Tuesday night since it becomes separated from the upper jet support, however, the parent mid/upper trough will continue to slowly swing into the Great Lakes Tuesday and Tuesday night pushing a strong cold front slowly through the region. A lead southern stream shortwave over the Lower Mississippi Valley Sunday night will be picked up by the digging upstream trough and ejected across the Ohio Valley through Monday. This will enhance warm/moist advection and isentropic ascent along a warm front Sunday night and Monday morning, so expect fairly widespread showers to spread across the region from west to east. A dry slot will quickly wrap in behind the warm front Monday afternoon, so maintained categorical PoPs Sunday night and Monday morning decreasing to chance in the afternoon. The progressive nature of the rain and lack of a deep Gulf connection will keep QPF in the 0.25 to 0.50 inch range, so do not expecting any flooding. The lone exception may be some minor nuisance flooding and stream rises in extreme NE Ohio and NW PA where a deep snowpack will be melting.

The lull in the rain showers will largely continue Monday night into Tuesday morning as the old low lifts well north of the region into Hudson Bay, so kept PoPs at slight chance to chance. However, confidence is increasing that showers will at least return to eastern areas Tuesday afternoon into Tuesday night as a wave of surface low pressure develops on the cold front in response to an impressive 150-165 knot H3 jet. Deterministic and ensemble guidance are tracking this wave from the Appalachians Tuesday night into New England Wednesday, so the amount of rain that can reach eastern Ohio and western PA depends on the exact track and whether or not a coastal low takes over along the East Coast. For now, just have high chance PoPs in the eastern counties Tuesday afternoon through Tuesday night. Showers will mix with and change to snow from west to east Tuesday night as strong cold air advection begins.

Highs will warm into the mid 40s/low 50s Monday, starting to cool into the mid/upper 40s Tuesday. Lows will fall into the low/upper 30s Sunday night, with mid/upper 30s Monday night. Much colder lows in the mid/upper 20s are expected Tuesday night.

LONG TERM /WEDNESDAY THROUGH FRIDAY/
Precip will transition to lake-effect Wednesday through Thursday as the deep mid/upper trough settles over the Great Lakes supporting broad cyclonic flow and strong cold air advection. H85 temps around - 10 C Wednesday could cool to -15 to -20 C by Thursday as a secondary cold front crosses the region. This could be another significant lake-effect snow event for the primary snowbelt east of Cleveland through NW PA depending on how the synoptic moisture fields and boundary layer wind direction end up. Shortwaves pivoting through the flow will likely move bands around a bit, so this will be watched over the coming days. Surface ridging attempts to build in Thursday night and Friday, and this combined with rising heights, drier air, and a lowering inversion should gradually end the lake- effect snow.

Highs in the low/mid 30s Wednesday will fall into the mid/upper 20s Thursday. A warming trend will start Friday, with low/upper 30s expected.

AVIATION /12Z Saturday THROUGH Wednesday/
MVFR ceilings linger with lake effect clouds downwind of Lake Erie in Northeast Ohio and Northwest Pennsylvania this morning, mainly affecting KERI (but also KYNG at times). High pressure building in from the southwest should gradually erode this lower deck of clouds and should be VFR by early afternoon.

Otherwise, expect VFR to prevail at all other TAF sites through the TAF period with some mid-level clouds (as low as 4,000 to 6,000 feet) drifting through at times this morning and maybe into the early afternoon hours.

Southwest winds will persist at 8-12 knots this morning. Winds gradually strengthen this afternoon and tonight, peaking at around 15-18 knots tonight with gusts up to ~25 knots. A strong southwesterly low-level jet paired with a temperature inversion will lead to low-level wind shear after 00Z this evening. Most model guidance has varying winds speeds of around 50 to 60 knots at 2kft. The low-level jet begins dissipating from the northwest after 09Z.

Outlook...Periods of non-VFR are expected late Sunday night through Tuesday as low pressure brings rain to the region. A cold front will cross Tuesday night, potentially bringing some rain showers and non-VFR with the front followed by lingering lake effect snow in Northeast Ohio and Northwest Pennsylvania on Wednesday.

MARINE
Lake Erie will remain active through the next 5 days, typical for December. Extended Small Craft Advisories on the western basin since a lull in the winds this morning will increase to SW at 20-30 knots late this afternoon into Sunday morning. This will lead to Gales on the central and eastern basins where SW winds of 25-35 knots are expected this evening into Sunday morning. This will build wave heights to 6-10 feet in the central and eastern basins this evening into Sunday morning. Winds and waves will gradually subside Sunday.
The strong SW winds will lead to water levels falling below the critical mark for safe navigation this afternoon and tonight before gradually rising Sunday morning, so also issued a Low Water Advisory.

Behind this system, there will finally be a better lull on the lake Sunday afternoon through Monday as winds oscillate between SSE and SW at speeds averaging 10-20 knots. Winds turn more westerly and start to increase Monday night and Tuesday though, and Small Craft headlines are likely Tuesday night and Wednesday.

CLE WATCHES/WARNINGS/ADVISORIES
OH...None.
PA...None.
MARINE...Small Craft Advisory from 3 PM this afternoon to 7 AM EST Sunday for LEZ142.
Low Water Advisory from 4 PM this afternoon to 10 AM EST Sunday for LEZ142>144-162>164.
Small Craft Advisory until 10 AM EST Sunday for LEZ143-144.
Small Craft Advisory until 4 PM EST Sunday for LEZ145-146.
Small Craft Advisory until 4 PM EST this afternoon for LEZ147>149.
Gale Warning from 4 PM this afternoon to 7 AM EST Sunday for LEZ147>149-166>169.