textproduct: Cleveland

SYNOPSIS

A strong low pressure system will continue to move northeast towards Nova Scotia as a surface trough lingers across the area today into Wednesday. Another low pressure system will move across the Great Lakes region on Wednesday, dragging a cold front east Wednesday night into Thursday. High pressure will build in on Friday.

NEAR TERM /THROUGH TUESDAY NIGHT/

Hazardous conditions are being observed across the entire area this afternoon as a result of a strong low pressure continuing to influence weather across the region. As this low continues to shift northeast towards Nova Scotia, a strong surface trough will linger and continue to influence the weather across northern Ohio and northwestern Pennsylvania. There are 2 primary hazards that will continue to impact the area through the period. These hazards include the strong winds and snowfall.

Focusing first on the strong winds, there currently remains wind gusts from the west-southwest of 40-50 mph being observed. Occasionally these gusts exceed 50 mph, but those seem to be isolated to areas closer to the lake shore. As the center of the low drifts northeast and the surface trough becomes established, winds will back to become northwesterly with gusts gradually weakening to around 30 mph by Tuesday morning. Elevated wind gusts from the northwest of 20-30 mph are expected to continue through Tuesday night. As a result of these elevated winds, a High Wind Warning/Wind Advisory remain in effect for counties along and west of I-71 through 10PM this evening and for counties east through 1AM Tuesday.

As winds gradually back this afternoon, areawide light snow showers will become focused across the snowbelt as lake effect snow begins to develop. These snow showers have the potential to be quite heavy as 850mb temps of -14 to -16C push south and a strong convergent boundary develops along the lakeshore. In addition, conditions across the area, including the very cold temperatures and gusty winds, will pose a risk of snow squall develop. The window for the heaviest snow is likely late this evening across NEOH and NWPA, continuing through tonight for NWPA. Snowfall rates of up to 1"/hour coupled with blowing snow could result in whiteout conditions. Impacts could be seen to this evenings commute and the Tuesday morning commute. Total snowfall accumulations between now and Tuesday afternoon are expected to range from 8-10 inches across NWPA, 4-6 across the Ohio snowbelt with the exception of Geauga County where locally higher amounts are likely. By Tuesday afternoon, there could be a brief lull in lake effect snow showers as a positively tilted trough axis moves over the area, allowing for winds to gain a bit more of a westerly component and 850mb temps warm a bit across the western basin. Opted to maintain at least chance PoPs given the mesoscale components, but rates on Tuesday would be much less. As this shortwave trough moves east, another round of lake effect snow is possible Tuesday night with an additional 2-4 inches possible in the Ohio snowbelt and 6-8 inches possible in NWPA. There remains some uncertainty as to where this second lake effect band sets up and whether it will linger close to the lakeshore with southwest flow or clip northern portions of the county's. As a result of this uncertainty, which will strongly influence the snowfall totals, opted to maintain the timing of current winter headlines but this will need to be monitored to determine if there is a long enough reprieve in snow between the first round today/tonight and the next round. Will expand/upgrade headlines as needed, but staying status quo for now.

Temperatures this afternoon are much cooler than previously forecast with observations all reporting in the upper teens to low 20s. These cold temperatures will lingering into the overnight hours with wind chill values falling into the single to sub-zero digits. Temperatures on Tuesday and Tuesday night will be in the low to mid 20s with wind chills in the single digits to teens.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/

Wednesday morning, a clipper system is expected to push east across the Great Lakes region, moving another cold front southeast Wednesday evening into the overnight hours. This system will bring another push of widespread snow across the area with generally 1-2" being observed as a direct result of the synoptic system. This cold front will be associated with strong frontogenesis and ample moisture in the 0-2km layer. Winds will also increase within this layer through a period from 00-06Z Wednesday night. As a result, there is a widespread potential for snow squalls NYE night. This could make for hazardous travel conditions as the holiday night comes to an end and people should plan accordingly to try and avoid travel during the hazardous conditions.

Across areas of the snowbelt, increased snowfall amounts are likely as heavy lake effect snow becomes established late Wednesday and persists to some capacity through at least Thursday afternoon. Current forecast suggests that additional winter weather headlines will be needed for this mid to late week system.

By Thursday night, a few light lingering lake effect snow showers are possible across the snowbelt, however should become more sporadic as moisture in the low levels begins to dry with an approaching high pressure system. There remains a good bit of uncertainty with the end timing of the lake effect, so this is valid to change in future updates.

Highs on Wednesday should be in the mid to upper 20s before the clipper system arrives and brings highs into the upper teens to low 20s on Friday. Overnight lows will remain in the teens through the period.

LONG TERM /FRIDAY THROUGH MONDAY/

On Friday, quieter weather should return to the area as high pressure builds east and allows for precipitation to end across the entire area. On Sunday into Monday, some models are hinting at another low pressure system, albeit weaker, moving east across the region but there is quite a bit of divergence among models at this point. If this system does come to fruition, could see another round of lake effect snow impacting the snowbelt sometime late Sunday into Monday. Highs through the period will generally remain in the upper 20s to low 30s with overnight lows falling into the mid teens to low 20s.

AVIATION /18Z Monday THROUGH Saturday/

Winds are likely peaking at the time of this issuance (18Z) with WSW winds gusting 35-50kts. Expecting a gradual turn to the W and then WNW, while simultaneously decreasing in intensity through the TAF period. Still should have gusts 25-35kts by 18Z Tuesday, however.

Wind blown snow showers across the region are going to transition to more of a lake effect type event, so terminals not typically vulnerable to lake effect snow should only have 3-5 more hours of snow shower chances, and then likely dry after that, specifically for FDY and MFD. Until then, IFR visibilities expected, but some variability also expected, along with blowing snow. Ceilings should stay MVFR mainly due to the high winds in the boundary layer.

Outlook...Non-VFR conditions across northeast Ohio and northwest Pennsylvania in lake effect snow showers through at least Thursday.

MARINE

As of 20Z, water levels likely near lowest point in the western basin at around 70 inches below low water datum and will take several hours to return to the more normal levels.

In the meantime, Gale and Storm Warnings continue for Lake Erie, for the western basin and central and eastern basins respectively. Expecting a gradual decrease in the winds that have gusted 40-55kts today. This will be a slow process however, and could take until early Tuesday for the lake to completely come down below Gale force winds/34kts. Wave heights today continue to push 20ft in the eastern basin, 14-18ft in the central basin, and lesser heights in the western basin largely due to varying water depths that do not support large wave heights because of the low water conditions.

Winds will largely remain onshore in a west southwesterly to northwesterly direction 15-30kts through Friday. Wave heights will not come down below 4ft in the central and western basins until that time.

CLE WATCHES/WARNINGS/ADVISORIES

OH...High Wind Warning until 10 PM EST this evening for OHZ003- 006>009-017>019. High Wind Warning until 1 AM EST Tuesday for OHZ010>014-089. Winter Weather Advisory until 1 PM EST Tuesday for OHZ011-012- 014-021>023-089. Lake Effect Snow Warning until 1 PM EST Tuesday for OHZ013. Wind Advisory until 1 AM EST Tuesday for OHZ020>023-030>033- 038. Wind Advisory until 10 PM EST this evening for OHZ027>029-036- 037-047. PA...High Wind Warning until 1 AM EST Tuesday for PAZ001-002. Wind Advisory until 1 AM EST Tuesday for PAZ003. Winter Weather Advisory until 4 PM EST Tuesday for PAZ001. Lake Effect Snow Warning until 4 PM EST Tuesday for PAZ002-003. MARINE...Gale Warning until 7 AM EST Tuesday for LEZ142>144-162>164. Low Water Advisory until 1 AM EST Tuesday for LEZ142>144- 162>164. Storm Warning until 7 PM EST this evening for LEZ145>147- 165>167. Storm Warning until 9 PM EST this evening for LEZ148-149-168- 169.