textproduct: Cleveland

WHAT HAS CHANGED

A Winter Storm Watch has been issued for much of the area Saturday evening into Monday as a widespread moderate to heavy snow is becoming more likely.

KEY MESSAGES

1) We are continuing to monitor a potentially significant snow storm for this upcoming weekend, with widespread moderate to heavy accumulations becoming more likely. A Winter Storm Watch has been issued for much of the area Saturday evening into Monday.

2) A prolonged period of sub-zero wind chills is expected beginning this Friday and will likely extend into at least mid- next week.

3) A cold front will move east through the area this morning, bringing a brief period of snow showers and gusty winds, mainly across the northern half of the area.

DISCUSSION

KEY MESSAGE 1...

A Winter Storm Watch has been issued for much of the area Saturday evening into Monday. An extension to the Watch may be needed across Northwest Ohio if trends persist.

Confidence continues to increase for a widespread moderate to heavy snow event across the region Saturday evening into Monday as a low pressure system moves northeast from the Tennessee Valley to the Mid- Atlantic. Ample Gulf moisture will combine with an arctic air mass, resulting in efficient snow processes and snow ratios likely to exceed 15:1. The latest QPF trends from ensemble guidance continues to slowly trend further north and northwest as models suggest a more amplified upper-level pattern across the Eastern CONUS. At this point, confidence is medium to medium-high (50 to 70%) for the current Watch area to receive at least 6 inches of snow with the highest totals found generally east of the I-71 corridor. Probabilities of snow totals of 12 inches or more remain low (10 to 20%), but cannot be ruled out.

KEY MESSAGE 2...

A prolonged period of sub-zero wind chills is expected towards the end of the week and into at least mid-next week as an arctic cold front moves through the area on Friday. A Cold Weather Advisory may be needed as early as Friday morning as a combination of modest west to northwest winds of 10 and 15 mph and temperatures falling into the single digits result in wind chills as low as -15 degrees F. These dangerously-cold wind chills are expected to persist through the day on Friday. Ambient temperatures of -5 to -10 degrees F will largely match the wind chills Friday night into Saturday morning as arctic high pressure leads to light winds. With the exception of Sunday, there remains medium- high to high confidence (70 to 100%) for daytime high temperatures to be below 18 degrees F into mid-next week. Another round of Cold Weather Advisories may be needed Monday night into Tuesday as wind chills fall to near -15 degrees F.

KEY MESSAGE 3...

A cold front is moving east through the area early this morning, with recent surface observations noting brief, elevated wind gusts of 40 to 45 mph behind the front. The latest satellite imagery suggests ample mid-level dry air in place which should limit much in the way of additional snow accumulations and coverage of snow showers. Some elevated mid- level moisture may return across far Northeast Ohio and Northwest Pennsylvania this morning, aided somewhat by ice- free areas of the eastern basin of Lake Erie, though any additional accumulations appear light, generally 1.5 inches or less. Will likely be able to expire the Winter Weather Advisory at the scheduled time of 7 AM this morning.

AVIATION /06Z Thursday THROUGH Monday/

Most of the airspace is VFR to start the TAF period outside of a final band of rain/snow with the cold front that will exit the TAF sites in the next hour or two. Another batch of snow will enter the northern half of the airspace overnight and move over Lake Erie. Some additional snow is possible at KTOL, KCLE, and KERI with this batch of snow and some non-VFR visibility is also possible. Some MVFR ceilings will enter with this wave and will have most sites back to MVFR later tonight. High pressure will build from the southwest and scour out the lower ceilings and trends will be to VFR and then high/no ceilings. Winds through the period will be southwest to west with gusts of 20 to 30 kts. Winds will diminish later in the period with no gusts with high pressure entering.

Outlook...Non-VFR possible in lake effect snow showers in NE OH and NW PA through Friday. Non-VFR possible late Saturday through early Monday in widespread snow showers.

MARINE

Breezy west to southwest flow continues on Lake Erie through Friday, generally in the 20-30 knot range. They may be a brief period of near gale-force winds late tonight into Friday morning, primarily in the eastern basin. There may also be low water in the western basin, especially this afternoon/evening when wind direction is most likely to be southwest.

High pressure and quiet conditions build in on Saturday. Low pressure tracks across the Ohio Valley, with northeast winds strengthening to around 20 knots on Sunday. Southwest flow of around 2-25 knots is most likely on Monday, though there is a very low probability of gale-force winds.

Ice on Lake Erie (which is mostly ice-covered at this point) will continue to thicken/expand through next week as several bouts of cold air impact the region.

CLE WATCHES/WARNINGS/ADVISORIES

OH...Winter Storm Watch from Saturday evening through Monday morning for OHZ008-009-017>019-027>029-036-037-047. Winter Storm Watch from Saturday evening through Monday afternoon for OHZ010>014-020>023-030>033-038-089. PA...Winter Storm Watch from Saturday evening through Monday afternoon for PAZ001>003. Winter Weather Advisory until 7 AM EST this morning for PAZ001>003. MARINE...None.