textproduct: Cleveland

WHAT HAS CHANGED

Made minor adjustments to slow the eastward progression of pops on Saturday. Raised pops in the east on Sunday. Trended high temperatures down slightly Sunday and Monday.

KEY MESSAGES

1) Scattered showers with isolated thunderstorms will drift south across inland portions of the area late this afternoon.

2) The next stretch of active weather will come Saturday with expanding coverage of showers and thunderstorms during the afternoon and evening. Isolated large hail and damaging wind gusts are possible. Additional showers and thunderstorms will linger across Northeast Ohio and Northwest Pennsylvania Saturday night and Sunday.

DISCUSSION

KEY MESSAGE 1... Low pressure is located over Maryland and Virginia this afternoon with cyclonic flow extending back across northern Ohio behind a cold front. While the airmass is undergoing drying, an agitated cu field can be seen on satellite imagery from near Canton to Bowling Green. Scattered showers are expected along this southward drifting boundary this afternoon with generally isolated coverage of thunderstorms. Storms should begin to diminish or push south of the area towards 7 PM.

KEY MESSAGE 2... Following a dry day on Friday, moisture will increase ahead of a cold front on Saturday. Coverage of showers will be limited on Saturday morning but expected to see considerable expansion during the afternoon as instability develop with a surface cold front moving east and a potent upper level trough digging across Lake Michigan. Slowed down the eastward expansion of pops slightly but do expect 70-80 percent coverage shifting east through the afternoon and evening. The upper level cold pool with 500mb temperatures of -14 to -16C will pivot east overhead Saturday night and should maintain some coverage of showers and thunderstorms, especially over the warm waters of Lake Erie. Depending on the progress of the surface front, some low level convergence could provide an added focus across Lake Erie. A Marginal Risk (level 1 of 5) for severe weather is forecast for Saturday with a low end threat of both damaging wind gusts and large hail. In addition, if any west to east bands of showers and thunderstorms become stationary off the lake into NW Pennsylvania then a heavy rain threat could develop.

Will need to make adjustments to pops on Sunday/Sunday night based on available moisture and energy moving through the trough aloft. 850mb temperatures fall to around 8C on Sunday and trended high temperatures down a degree or two for both Sunday and Monday. There is some spread among the long range models with respect to the progression of the trough on Monday. Surface high pressure and dry conditions are expected on Tuesday.

AVIATION /18Z Thursday THROUGH Tuesday/

Primarily VFR conditions are expected to continue through the TAF period as high pressure builds across the region. Some light and isolated showers will continue across Northwest Ohio and across inland terminals (mainly TOL and MFD/CAK/YNG) through later this afternoon. FEW/SCT low-to-mid level clouds remain possible in and near these isolated showers. Any reductions to non-VFR will improve to VFR as the high moves overnight tonight. Did include a TEMPO group for BR at MFD as guidance suggests MVFR ceilings possible near daybreak.

Generally northeasterly winds 5-10 knots will shift easterly and decrease to 5 knots or less this evening and overnight under high pressure. Southeasterly winds of 5-10 knots will be favored by late Friday morning.

Outlook...Non-VFR expected in showers and thunderstorms on Saturday. Non-VFR conditions may continue Saturday night into Sunday in lake enhanced showers and storms across Northeast Ohio and Northwest Pennsylvania.

MARINE

Slightly elevated northeast winds 10-15 knots will continue through this evening. Wave heights in the western and central basins may briefly increase to 1-3 feet. By this evening, high pressure builds overhead allowing for winds to shift easterly to southeasterly while decreasing to 5-10 knots Friday into Saturday. Ahead of an approaching low pressure system this weekend winds will shift southwesterly on Saturday. A cold front will push east across the region Saturday night into Sunday with winds turning northwesterly in the wake of the front. Northwesterly winds increase to 15-20 knots by Sunday with onshore flow likely leading to wave heights building to 2-4 feet in the central and eastern basins Sunday and Sunday night. Marine headlines may be needed to end the weekend before high pressure builds overhead early next week.

CLE WATCHES/WARNINGS/ADVISORIES

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