Marine Weather and Tide Forecast for Sheffield Lake, OH

NEAR TERM /THROUGH MONDAY NIGHT/
9:30 PM Update...

Updated Crawford County, PA to a Lake-Effect Snow Warning through 18Z Tuesday. Most of the area has made the switch over to snow, with only some rain lingering along the lakeshore and near the OH/PA border as strong cold air advection combines with wet bulb cooling. Any leftover rain in far eastern Ohio should switch over to snow by Midnight, except it will likely take longer at the lakeshore. The forecast snow amounts remain on track, with reports from snow spotters and ASOS sites generally ranging from a trace to a few tenths this evening. The synoptic snow will gradually exit from west to east tonight as the deepest moisture pulls off to the NE with the exiting 850 mb low, but lake enhancement and upsloping should put down a solid 1-3 inches over the higher terrain areas inland from the lake, with locally up to 4 inches, before the steadiest snow ends.

After reviewing HRRR guidance, there is a signal for a lull Monday morning into much of the afternoon as the drier air works in, with N to NW fetch lake-effect bands producing only intermittent snow showers. This will likely lessen the impacts and overall snow amounts before the next trough and better associated moisture and lift drop across the area Monday evening into early Tuesday. It is at that time when the better lake-effect bands should set up as the improved moisture and lift combines with backing boundary layer flow (increasing fetch) and strengthening south shore convergence. This still looks like the most interesting part of this extended event, with one dominant band attempting to develop from eastern Cuyahoga County east through the primary snowbelt and another band with a connection to Lake Huron pivoting across NW PA. With all of this in mind, confidence was highest to upgrade Crawford County, PA to a warning, with HRRR PMM amounts solidly in the 8-12 inch range from now through Tuesday across inland Erie and Crawford Counties, which jives closely with our ongoing snowfall forecast. Warning amounts are possible in Geauga, and perhaps eastern Cuyahoga and inland Ashtabula Counties, but given the lengthy lull much of Monday, not sure that total snowfall for this event will exceed 5 or 6 inches in many areas, and impacts will also be spread out and manageable. This will continue to be monitored since heavy snowfall is possible in those areas Monday night.

Original Discussion...

The main weather message with this forecast update is the potential for lake effect snow and accumulating snowfall for both the primary and secondary Snowbelt of NEOH and NWPA. This lake effect snow event will start this evening and lingering through Tuesday.

We have made some updates to the winter weather headlines. A Winter Weather Advisory for Lake Effect Snow is now in effect for all the primary and secondary Snowbelt of NEOH and NWPA starting this evening. The end time of the advisory varies from west to east Monday into Tuesday as this lake effect event transitions across the area. A Lake Effect Snow Warning has been issued for inland Erie County PA where the highest snowfall totals are expected and have significant winter weather impacts. Be sure to look at the most recent updated WSW products and winter weather headlines for specific details including timing, forecast snowfall amounts, and expected impacts.

The water vapor imagery and ther GOES-19 satellite channels show very nicely a large and deep upper level trough is digging across the Midwest and western Great Lakes. This deep trough will be will bring down a blast of cold and bring our first round lake effect snow for this season. As of 3 pm, the surface cold front was approaching the Ohio/Pennsylvania state line. Behind the front, northerly to northwesterly has started the cold air advection into our area. After a lull this afternoon with the rainfall earlier today, recent radar trends have shown an uptick in precipitation developing across northwest Ohio and western Lake Erie. Initially the precip will be in the form of rain showers. During the evening, there will be a transition to wet snow or graupel mixing in before all the precip changes over to snow showers. There will be a period of lake enhanced precip this evening with the northerly flow off the lake for most of northern Ohio and NWPA. Later overnight and into Monday morning, we will see bands of lake effect snow and possible intense snow squalls. 850 mb temps will drop to -10C to -12c by early Monday morning. Very strong lake induced instability will develop with CAPE values 1000-1200 J/KG, thanks to an average lake water temp of 53F. Most of northern Ohio and NWPA will see accumulating snowfall by early Monday morning which could impact the morning commute.

High-res model guidance still shows some mesoscale features that we will have to keep an eye on tonight through Monday night. One potential feature may be a Lake Huron connection trying to develop later tonight and come across western Lake Erie into NWOH early Monday morning. This Lake Huron connection if it develops, may gradually pivot eastward during the day Monday down the lakeshore. It could be near the Cleveland area around midday and near the Ashtabula/Erie County PA area by Monday evening. Our snowfall ratios will start around 8:1 this evening and increase to around 15:1 by tomorrow morning. With this being a wetter snowfall and some trees still have foliage, there may be an increase risk for downed tree limbs onto power lines causing scattered power outages.

Several inches of snowfall is expected in the winter weather advisory area by tomorrow morning. Snowfall rates may exceed 1 inch per hour in the more organized lake effect bands. There is the potential for a few isolated intense snow squalls that could have rates of 1 to 2 inch per hour in localized areas of the Snowbelt. Temperatures will fall into the mid/upper 20s to around 30 degrees tonight. High temperatures on Monday will stay in the 30s. with scattered lake effect snow showers and squalls.
Accumulation during the day will be dependent on where bands persist and snowfall rates to overcome temperatures being near or slightly above freezing to account for melting.

The northerly flow will become west-northwesterly by Monday evening and night. The lake effect snow potential will also shift to more of the primary Snowbelt of NEOH and NWPA Monday night. There may be a Lake Huron connection that could impact NWPA and the Erie PA area most of Monday night before it shifts eastward Tuesday morning. Overall 1 to 3 inches of snowfall will be possible outside of the advisory area. 2 to 5 inches of snowfall with localized higher amounts possible in the advisory area. 6 to 11 inches will possible be in the warning area which is inland Erie County PA.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/
Ongoing lake effect snow will slowly wind down for NEOH and NWPA Tuesday morning lingering into midday. The low level flow will become southwesterly on Tuesday and that will slowly shut the lake effect off. The low levels of the atmosphere will also start warming on Tuesday and become less favorable from west to east. We have all of the headlines ending by midday on Tuesday.
Lingering lake effect will may hug closer to the lakeshore Tuesday afternoon and mix with or change over to rain showers.
A strong low pressure system will move across the Upper Great Lakes Tuesday into Tuesday night. Strong gusty southwesterly winds will increase 15 to 25 mph with gusts to 40 mph Tuesday and Tuesday night. Another cold front will move through the region on Wednesday and change the flow to westerly and eventually west-northwest. This W-NW flow will bring back the chance for scattered lake effect rain showers possible mixing with some wet snow flakes late Wednesday and Wed night.

LONG TERM /THURSDAY THROUGH SUNDAY/
The end of the week and next weekend will favor nicer weather as temperatures rebound back to more seasonable averages or even a little above average. An upper level ridge will build in over the Great Lakes and Ohio Valley by the end of the week and next weekend with milder weather and fair weather. A surface high pressure system will also build over the Ohio Valley by Friday.
Temperatures will climb back into the 50s to near 60s next weekend.

AVIATION /00Z Monday THROUGH Friday/
Rain will continue to mix with and change to wet snow from southwest to northeast through early tonight allowing widespread IFR and occasional LIFR conditions to continue, although there should be improvement at KTOL and KFDY after 06Z or so as the steadiest precip shifts east. This will lead to these NW Ohio terminals mostly drying out for Monday with VFR returning except for tough to time passing snow showers off Lake Michigan.
Farther east in north central and northeast Ohio through northwest PA, the rain that slowly changes to snow tonight will remain steadier through at least mid morning Monday, with resultant IFR or lower being more common through Monday morning.
This is due to the widespread synoptic precip transitioning to lake enhanced and lake-effect snow over the higher terrain inland from the lakeshore. Confidence decreases on Monday from about 15Z onward through the afternoon/end of the TAF cycle regarding the coverage of snow showers. Lake-effect snow showers will continue, but drier air should reduce the coverage in the afternoon and early evening, with backing winds also pushing the bands slowly to the east. The best estimate at this time is for the most frequent snow showers to end at KMFD by early afternoon and by late afternoon at KCLE, KCAK, and KYNG. All of these sites should see some VFR by mid to late afternoon. The frequent snow showers and MVFR/periods of IFR are likely to linger at KERI much of the afternoon.

N winds this evening will gradually back to NW tonight and Monday morning, with speeds of 10-15 knots gusting to 20-25 knots at times. Winds will continue to back to WNW by Monday evening, with gradually diminishing speeds, but still gusting to around 20 knots near the lakeshore affecting KERI.

Outlook...Periods of non-VFR conditions will continue in northeast Ohio and northwest Pennsylvania with lake effect showers through midweek.

MARINE
Hazardous marine conditions are expected to persist for much of this week as an active weather pattern continues to impact the region.
Today, winds on Lake Erie will gradually shift from northeasterly to more north-northwesterly by this evening as a low pressure system tracks east just south of the lakeshore. This low will move off the New England Coast on Monday, resulting in a surface trough with north-northwest flow lingering over the east Great Lakes. Given the fetch, lake effect snow is likely inland, but over the water much should remain rain with an isolated potential for thunder in the most well developed bands. Winds will remain sustained at 20 to 30 knots with the strongest winds across the central basin. As a result, a Small Craft Advisory remains in effect for the entire southern lakeshore of Lake Erie through Tuesday.

On Tuesday night, hazardous marine conditions will continue as another low pressure system centered near Hudson Bay moves an associated surface trough east across the area. This will once again increase the gradient, moving a warm front east on Tuesday night followed by a cold front on Wednesday. During this period, there is a potential that the central and eastern basins of Lake Erie will see gale force southwesterly winds. Will need to monitor the strength of winds expected in the coming forecasts, but this period will definitely need a Small Craft Advisory if not a Gale Warning.
By Wednesday night, high pressure should start to nudge northeast, allowing for winds to slowly diminish through the day on Thursday.
By Thursday night, west-northwest winds should fall below 20 knots and allow for a break in the hazardous conditions across the lake.
Until then, waves will frequently exceed 4 feet and winds will remain stronger than 20 knots. Boaters should use caution this week if going out on the lake.

CLE WATCHES/WARNINGS/ADVISORIES
OH...Winter Weather Advisory until 1 PM EST Monday for OHZ010-019- 020-029>031.
Winter Weather Advisory until 1 PM EST Tuesday for OHZ011>014- 089.
Winter Weather Advisory until 10 AM EST Tuesday for OHZ021>023.
PA...Winter Weather Advisory until 1 PM EST Tuesday for PAZ001.
Lake Effect Snow Warning until 1 PM EST Tuesday for PAZ002-003.
MARINE...Small Craft Advisory until 1 PM EST Monday for LEZ142-143.
Small Craft Advisory until 7 PM EST Tuesday for LEZ144>149.