textproduct: Cleveland

WHAT HAS CHANGED

Increased POP's slightly in NW PA and Ashtabula County, OH for the next several hours to account for light snow showers that continue to blossom over/near eastern Lake Erie amidst moist isentropic ascent preceding a subtle shortwave trough axis aloft. These snow showers may impact NW PA and far-NE OH through this mid-afternoon and produce a coating of fresh snow accumulation, especially along grassy surfaces.

KEY MESSAGES

1) Scattered lake effect snow showers are possible this afternoon and evening in Northwest Pennsylvania.

2) Quiet weather and warmer temperatures are expected on Friday and Saturday.

3) A system may bring precipitation to the region on Sunday and Monday, though there is a lot of uncertainty regarding storm track, precipitation type, and subsequent impacts.

DISCUSSION

1) Warm air advection will allow temperatures to rise into the upper 30s to low 40s early this afternoon before a cold front swings through, bringing overnight low temperatures down into the upper 10s to low 20s tonight. A cold airmass will move in behind the cold front with 850 mb temperatures down to -14 C contributing to lake effect showers this evening into tonight. A mostly ice covered Lake Erie (~60-70%), short duration of cold air, and air that just isn't that cold will limit shower coverage and area extent to mainly Northwest Pennsylvania. Little to no snow accumulation expected.

2) High pressure over the area on Thursday departs to the east coast by Friday and Saturday. As low pressure moves eastward north of the Great Lakes, broad southwest flow will lead to some pleasant weather to end the month, as we expect above normal temperatures and some sunshine both days.

3) Early next week, a baroclinic zone will set over the region, with high pressure and a cold airmass to the north, and broad southwest flow of warm, moist air from the south. Many models have isentropic lift leading to an area of winter weather impacting the region sometime Sunday night into early next week. There is a lot of uncertainty with the details of this system, especially regarding the strength of the northern high pressure to our north (which could potentially push precipitation south away from the area if its strong enough), moisture content, and location/track of a low along the baroclinic zone. However, ensemble guidance as a whole has trended towards higher QPF/snow and higher probabilities of accumulating snowfall, and these trends are worth paying attention to moving forward.

AVIATION /12Z Wednesday THROUGH Sunday/

Generally expect any lower ceilings to improve to VFR across most of the area early this morning, although lingering MVFR ceilings will likely persist at KYNG/KERI through mid to late morning. Lake effect clouds may keep ceilings in the 3500 to 5000 ft AGL range across portions of Northeast Ohio and Northwest Pennsylvania through tonight, especially if any light lake effect snow showers manage to develop.

Southwest winds 8 to 14 knots are expected early this morning before winds shift to the west and increase to 10 to 20 knots with gusts to 20 to 25 knots this afternoon. Gusts may periodically approach 30 knots this afternoon, best chance at KFDY. Winds will diminish after sunset with light and variable winds developing overnight.

Outlook...Non-VFR possible as snow moves southeast across the area Saturday night.

MARINE

West winds to 15 to 20 knots with periods of winds as high as 25 knots are expected as a cold front moves east across Lake Erie today. West/northwest winds will gradually diminish as the pressure gradient relaxes tonight and expect wind speeds to decrease to 10 knots or less by late tonight. Light westerly flow is expected during the day Friday before winds shift to the south/southwest and increase a bit Thursday night. Winds will gradually increase as a cold front approaches from the west Friday and wind speeds to about 20 knots are likely late Friday into early Saturday. Winds will diminish for a brief period as they shift to the north/northwest late Saturday afternoon into Saturday evening, but expect north winds to increase to 10 to 20 knots as strong high pressure builds in behind the cold front Saturday night into Sunday.

While Small Craft Advisories remain suspended due to extensive ice coverage across the majority of the lake, waves in ice free areas may build to 3 to 6 feet during periods of stronger winds. Any wind shifts and elevated winds will result in movement of lake ice, which could impact shipping lanes.

CLE WATCHES/WARNINGS/ADVISORIES

OH...None. PA...None. MARINE...None.