textproduct: Cleveland

WHAT HAS CHANGED

No significant changes to the previous forecast.

KEY MESSAGES

1) Showers and thunderstorms will arrive from the west this afternoon and continue into this evening. The primary concern is heavy rain and isolated flash flooding, especially across Northeast Ohio and Northwest Pennsylvania.

2) Showers and thunderstorms will return Saturday night through Sunday with a low pressure system and cold front. Some stronger storms are possible Sunday afternoon and evening.

DISCUSSION

KEY MESSAGE 1... The latest radar and satellite imagery depict another large cluster of showers and thunderstorms towards the west across Indiana, with SPC mesoanalysis revealing a tight MLCAPE gradient oriented generally NNW to SSE. Convection trends have already begun following this gradient, with the stronger and more organized storms beginning to dip further south across Indiana and southwest Ohio. Modest residual westerly 850 mb flow of 30 to 35 knots across Northwest Ohio may allow for some showers and storms to redevelop this afternoon, though the threat for any stronger storms across our area appears to be decreasing. There is a somewhat low potential for some heavier rain and isolated flash flooding later this evening as a trough swings south through the Eastern Great Lakes, as the arriving 850 mb jet may result in a stalled boundary somewhere across far Northeast Ohio and Northwest Pennsylvania.

Otherwise, the heavy rain threat for Thursday night into Friday appears to be decreasing as QPF guidance continues to trend further south into the Ohio Valley. Could still see some scattered showers and storms Thursday night into Friday, particularly along or near the US-30 corridor, but the overall heavy rain threat appears to be decreasing.

KEY MESSAGE 2... The next period for unsettled weather will be Saturday night through Sunday as a low pressure system moves east through the Great Lakes, extending a cold front across the area Sunday night. Will continue to monitor the threat for any stronger storms, especially Sunday afternoon with the latest guidance suggesting a potent 700 mb shortwave of 35 to 40 knots entering the area.

AVIATION /06Z Thursday THROUGH Monday/

The main concern this morning is once again fog as an inversion sets up over wet ground. Mid-level clouds give some uncertainty in how widespread the fog will be, but continued to bring in LIFR visibilities at typical favored locations (KFDY, KMFD, KCAK, and KYNG) and MVFR to IFR elsewhere. Once the fog burns off this morning, it will take some time for cigs to improve, so kept MVFR cigs through late morning or early afternoon. VFR is then expected from mid afternoon through tonight as high pressure nudges into the Great Lakes. The band of showers this evening and tonight over southwestern areas is trending farther southwest, so limited VCSH to KFDY.

Light and variable winds early this morning will become W to NW at 5-10 knots by late morning through the afternoon.

Outlook...Non-VFR possible in showers and thunderstorms Saturday afternoon into Sunday.

MARINE

Quiet conditions will continue on Lake Erie through the start of the weekend as pressure gradients will be weak. Light and variable winds today and tonight will become ENE at 5-10 knots Friday and Friday night as high pressure briefly strengthens across the Great Lakes before turning SE at 5-10 knots Saturday as a warm front approaches the lake. Winds will turn SW and increase to 15-20 knots by Sunday behind the warm front as the gradient tightens in response to low pressure moving east through the central Great Lakes. This low will drag a cold front across the lake Sunday night, turning winds NNW at 10-15 knots for late Sunday night and Monday.

CLE WATCHES/WARNINGS/ADVISORIES

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