Marine Weather and Tide Forecast for Mansfield, OH

KEY MESSAGES
1) Widespread rain will develop early Wednesday morning and quickly change to snow by midday, with snow continuing into Wednesday night. This could cause a messy evening commute.

2) Temperatures will rapidly fall below freezing Wednesday morning and into the teens Wednesday night into Thursday with below zero wind chills, posing a minor cold exposure risk.

3) Lake-effect snow will continue in the snowbelts of NE Ohio and NW PA Thursday, and this will result in additional accumulations and locally hazardous travel conditions.

4) Additional rounds of light snow are expected Friday through early next week, with temperatures trending even colder this weekend and early next week. This will likely lead to the coldest air of the season and wind chills well below zero at times.

DISCUSSION

KEY MESSAGE 1...

We will return to Winter Wednesday as a large mid/upper trough digs through the Great Lakes and Ohio Valley regions. The initial northern stream low associated with this trough will progress across Ontario and Quebec through the day, dragging an arctic cold front through our region Wednesday morning. As the mid/upper trough digs, shortwave energy in the base of the trough will support surface cyclogenesis on the arctic frontal boundary over the Lower Ohio Valley Wednesday morning. This low will lift toward the New England region through the day while quickly transferring its energy to a coastal low by Wednesday night. As the low develops, increasing moisture advection and isentropic lift will lead to widespread rain spreading into the region by sunrise Wednesday. Cold air advection behind the arctic front and wet bulbing will quickly change this rain to snow from west to east Wednesday morning. Most of the area will be snow by 15Z, with the OH/PA border seeing snow by 17Z. This will set up a messy evening commute. The heaviest snow will fall Wednesday afternoon and evening across the primary and secondary snowbelts of NE Ohio and across NW PA as 850 mb temps falling below -15 C combined with NW boundary layer flow and deep wraparound moisture leads to lake enhancement. This will be especially notable in southern Cuyahoga, northern Summit, northern Portage, Geauga, southern Lake, inland Ashtabula, southern Erie, and Crawford Counties where upsloping will lead to higher snowfall amounts. The lake enhanced synoptic snow will gradually wind down from west to east Wednesday night.

KEY MESSAGE 2...

Non-diurnal temperatures will occur Wednesday as temperatures quickly fall behind the arctic front. Highs will occur around sunrise, when upper 30s to around 40 are expected, then fall through the 20s in the afternoon. This could cause a flash freeze on any wet roads, sidewalks, and surfaces that are not treated, but the biggest impacts from the flash freeze will likely occur just after the morning commute. As 850 mb temps drop to -19 to -21 C Wednesday night and Thursday, temperatures will continue to plummet into the teens. Highs Thursday will struggle to reach the 20s, with below zero wind chills Wednesday night and Thursday morning. While this is not at criteria for a Cold Weather headline, it will still pose a cold exposure risk.
People should limit time outdoors and dress in layers if you need to go out.

KEY MESSAGE 3...

As the lake enhanced synoptic snow ends late Wednesday night, we will transition to lake-effect snow by Thursday morning, and this will continue into early Thursday night before ending. NW boundary layer flow will support multiple bands across the primary and secondary snowbelts of NE Ohio, as well as NW PA.
The very cold 850 mb temps will lead to plenty of lake induced instability, but the main question mark is the degree of leftover boundary layer moisture. Forecast soundings are trending drier as the coastal low takes over, and with a short fetch, this should keep additional snow amounts Thursday from getting out of hand. The total snowfall from Wednesday through Thursday should stay in the Advisory range for the most part, with 2 to 5 inches across the primary and secondary snowbelts of NE Ohio and 3 to 7 inches across inland NW PA. The wildcard is a potential Lake Huron band into eastern Erie County during the day Thursday. Some HRRR guidance and the 12Z RGEM is higher on snowfall totals in that area, but given the lower confidence in the moisture profile, kept snowfall in the Advisory range at this time. This will be monitored for locally higher snow.
Shortwave ridging will bring the snow showers to an end Thursday night. Outside of the snowbelt areas, total snowfall Wednesday through Thursday should average 1 to 3 inches in north central Ohio and 1 inch or less in NW Ohio.

KEY MESSAGE 4...

Deep troughing will continue across central and eastern North America through early next week, with a series of clipper systems and lake-effect snow keeping the pattern very cold and active. Temperatures will rebound into the low 30s Friday and Saturday ahead of a pretty strong mid/upper shortwave and associated surface low crossing the Great Lakes. This clipper will bring widespread light snow late Friday into early Saturday, with additional lake-effect snow possible Saturday and Sunday in far NE Ohio and NW PA, although WSW boundary layer flow may keep the bulk of this in western NY. The clipper itself is trending more potent and will need to be watched for higher snow amounts than currently forecasted. Another and colder push of arctic air will follow the clipper late Saturday and Sunday, with temperatures falling back through the teens and low 20s.
Another clipper Monday will bring additional snow and even colder air for next week, with lake-effect snow showers continuing at times. Temperatures Monday and Tuesday will likely stay in the teens. Below zero overnight and morning wind chills are likely Saturday night and Sunday night, and these wind chills will be even colder early next week, so Cold Weather Advisories will be possible.

AVIATION /00Z Wednesday THROUGH Sunday/
VFR across the TAF sites with deterioration to MVFR and IFR in low ceilings and rain/snow. Ceilings will drop to MVFR from west to east late tonight into Wednesday morning ahead of a strong cold front. This cold front will bring a rain/snow mix as it sweeps northwest to southeast through the area Wednesday morning into the afternoon, with rain quickly transitioning to snow as colder air arrives behind the front. A more widespread snow with IFR vsbys is becoming more likely along and east of the I-71 corridor in the afternoon and evening as another system develops near the Mid- Atlantic. Lower confidence of a widespread snow west of I-71 and thus only mentioned light snow showers for TOL/FDY at this time.

Winds are out of the south to southwest this evening, 10 to 15 knots with periodic gusts of 20 to 25 knots. Winds will briefly diminish to 10 to 12 knots overnight, before abruptly shifting towards the northwest behind the cold front late Wednesday morning and afternoon, 15 to 20 knots with periodic gusts up to 30 knots possible, particularly along and west of the I-71 corridor.

Outlook...Non-VFR expected to continue Wednesday night and Thursday, most numerous east of the I-71 corridor in lake effect snow showers. Non-VFR likely in snow showers on Friday and Saturday. Non-VFR may linger across NE OH and NW PA on Sunday.

MARINE
Southwest winds 20-30kts with wave heights 4-8ft in the central and eastern basins of Lake Erie ahead of a pair of cold fronts will become northwesterly 20-30kts Wednesday through Wednesday night and wave heights continuing at 4-8ft. Small Craft Advisories through this period are in effect through the early part of Thursday. Winds southwesterly/offshore 15-25kts Thursday night through Friday keep the wave heights in the open water zones around 4-8ft once again, but in the nearshore zones around 1-2ft.

CLE WATCHES/WARNINGS/ADVISORIES
OH...Winter Weather Advisory from 9 AM Wednesday to 7 PM EST Thursday for OHZ011>014-089.
PA...Winter Weather Advisory from 11 AM Wednesday to 1 AM EST Friday for PAZ001>003.
MARINE...Small Craft Advisory until 10 PM EST this evening for LEZ142>144.
Small Craft Advisory until 1 PM EST Thursday for LEZ145>149.