textproduct: Cleveland

SYNOPSIS

Low pressure will move east through the eastern Great Lakes on Wednesday, extending a cold front across the region Wednesday evening into Thursday. Weak high pressure will begin to build across the area late Thursday and may persist through much of the weekend.

NEAR TERM /THROUGH WEDNESDAY NIGHT/

Main concern for the near term period will be periods of heavy lake effect snow through Wednesday night and the potential for snow squalls late Wednesday afternoon and evening. Winter Weather Advisories have been hoisted from 1 PM Wednesday through 7 AM Thursday for the secondary snowbelt, including adjacent Counties such as Wayne, Stark, and Mahoning. All other headlines remain unchanged with this update, though snowfall amounts have been increased, particularly near northern Ashtabula (OH) and Erie (PA) Counties where an additional 1.5 to 2 feet of snow is becoming more likely.

Lake effect snow continues across Northeast Ohio and Northwest Pennsylvania this afternoon as 850 mb temperatures remain cold (-15 to -16C) with primarily northwest flow aloft. The most potent lake effect snow band thus far is impacting portions of far eastern Cuyahoga and Geauga Counties and could persist over the next several hours with surface convergence largely keeping the band in place (W to NW flow north of the band with W to SW flow to the south of the band). The expectation is for this band to gradually lift north across the snowbelt late tonight into Wednesday morning as a weak clipper sweeps through the area, shifting low-level flow towards the southwest. Outside of the snowbelt, generally a light snow of 1 to 3 inches is anticipated areawide into Wednesday morning.

Attention then turns towards the potential for a long-fetch single band to develop along or near the lakeshore of far Northeast Ohio and Northwest Pennsylvania as 850 mb flow favors a westerly direction ahead of a stronger clipper system and cold front expected to arrive by late Wednesday afternoon and evening. Snowfall rates within the band will likely reach 1 to 2 inches per hour, contributing to up to a foot of snow by around 1 PM Wednesday. There will be a sharp gradient, with locations just south of the main band expected to have significantly less snow accumulation.

A stronger clipper system and cold front will then arrive across the area late Wednesday afternoon and evening, bringing an additional 6 to 12 inches of snow across the primarily snowbelt as northwest flow quickly shifts the single band onshore. Confidence is high for snowfall rates to reach 1 to 2 inches per hour, particularly across far Northeast Ohio and Northwest Pennsylvania late Wednesday afternoon and evening. Outside of the snowbelt, generally 2 to 5 inches is expected areawide, with the highest amounts located generally east of the I-71 corridor. In addition to snow amounts, the environment will be primed for snow squalls Wednesday afternoon and evening which could result in brief whiteouts and quickly- coated roadways. This threat is areawide, but is most likely across North and Northeast Ohio, and into Northwest Pennsylvania (see the WPC Key Messages graphics for a regional look at the snow squall potential for New Year's Eve).

Temperatures will remain cold for the near term period with wind chills in the teens to single digits. Temperatures will be the coldest late Wednesday night into early Thursday morning behind the cold front, with wind chills near or slightly below zero.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/

Lake effect snow will likely continue across the primary snowbelt Thursday morning into the early afternoon as 850 mb temperatures fall to around -20C with little to no boundary layer shear in place. A trough will swing east through the Upper Great Lakes Thursday night into Friday, though the current thinking is that any lake effect snow would appear to favor western NY given strong southwest surface flow.

Cold temperatures will persist for the short term period with wind chills in the teens to single digits.

LONG TERM /SATURDAY THROUGH TUESDAY/

A quieter, albeit cold, weather pattern is favored to persist for the long term period as several areas of weak high pressure build across the region. Aloft, the region is expected to remain wedged between an upper-level trough to the northeast and a weakly-defined ridge to the west.

Temperatures will warm up slightly into the low 30s, though will still remain below average for this time of the year.

AVIATION /00Z WEDNESDAY THROUGH SUNDAY/

Ceilings across the region are largely between 2500 and 4000 ft with the lower ceilings largely coinciding with the lake effect snow showers. Snow showers will continue to drive the operational flight categories through much of the period with intermittent bands of lake effect snow showers. There will be a push of snow later this evening through the first part of the overnight where visibility should fall into the IFR range for most terminals. A more organized band of snow should develop over Lake Erie and push into KERI late tonight into Wednesday and allow for more sustained IFR with periods of LIFR with moderate snow. During the afternoon on Wednesday, a reinforcing cold front will move through the region and bring another round of snow for the entire area and likely IFR conditions. There is potential that snow could end up being organized snow squalls with the potential for LIFR conditions with quarter mile or less visibility. There is higher confidence of LIFR snow bands at KCLE and KERI with the lake effect component, but additional mentions may be needed elsewhere as the snow squall threat continues to be realized. Winds will be westerly with gusts to 20-25 kts. These gusts could pick up to as high as 30 kts with the front on Wednesday afternoon. Winds will shift to the northwest behind the front.

Outlook...Non-VFR conditions are expected across the region due to lake effect snow and clouds through Thursday night and then with low ceilings Friday through Saturday.

MARINE

Conditions have improved on Lake Erie, so the Gale Warning has been expired at 4 PM. West winds around 20-25 knots will continue through Friday. A Small Craft Advisory has replaced the Gale Warning in the central and eastern basin of Lake Erie. The worst conditions are expected for about a 6 hour period Wednesday evening into Wednesday night following the passage of a cold front. This is when winds will become northwest and increase to 25-30 knots, especially in the central and eastern basin where waves may climb to 7-9 feet. The small craft advisory east of The Islands will then continue through 03Z Friday, though there is a chance it may need to be extended further into Friday (confidence wasn't high enough at this point.

High pressure builds in over the weekend and conditions improve across Lake Erie with conditions at or below 10 kts & 2 ft.

CLE WATCHES/WARNINGS/ADVISORIES

OH...Winter Weather Advisory from 1 PM Wednesday to 7 AM EST Thursday for OHZ010-020>023-031>033. Winter Weather Advisory until 7 AM EST Thursday for OHZ011. Lake Effect Snow Warning until 7 AM EST Thursday for OHZ012>014-089. PA...Lake Effect Snow Warning until 7 PM EST Thursday for PAZ001>003. MARINE...Small Craft Advisory until 4 AM EST Wednesday for LEZ142>144. Small Craft Advisory until 10 PM EST Thursday for LEZ145>149.