textproduct: Cleveland

WHAT HAS CHANGED

No significant changes to the previous forecast.

KEY MESSAGES

1) Patchy fog is possible this morning.

2) Scattered showers expected tonight through Friday generally near or west of I-77.

3) Periodic thunderstorms are expected Saturday night through Sunday evening. There is a low risk for severe weather, especially Sunday afternoon.

DISCUSSION

KEY MESSAGE 1... Moist surface conditions due to yesterday's rain, and light surface winds with weak high pressure overhead will result favor fog formation this morning. Patchy fog is possible across portions of the forecast area, especially for our southwest counties (e.g. Hancock to Knox Counties) where there could be greater coverage of fog.

KEY MESSAGE 2... The stationary front that has been impacting the broader region has sagged south towards the lower Ohio Valley. A series of mid-level shortwaves are expected to traverse the broader northwest flow, with additional rounds of convection expected. The latest high resolution models have thunderstorms with heavy rain displaced to our southwest, with mainly rain showers affecting parts of northern Ohio tonight into Friday. This is generally west of I-77 with our southwest counties (Hancock to Knox Counties) seeing the best shot at rain showers.

KEY MESSAGE 3... Low pressure moves eastward across the Great Lakes region, lifting a warm front across the area Saturday night. The entire forecast area will be within the warm sector on Sunday, with very humid conditions expected. A couple rounds of thunderstorms are expected with this system.

The first round of thunderstorms is expected with the warm front Saturday night, generally moving west to east. This is most likely to occur overnight, though a few models do linger this activity into the morning ours, depending on the speed in which the warm front lifts across the area. There is a low risk for severe weather.

Additional convective development is expected Sunday afternoon and evening. High instability along with modest mid-level shear may produced an organized severe weather threat. As always, there is some uncertainty with timing/location of greatest severe weather threat but this time frame is worth keeping an eye on.

The cold front sweeps through Sunday night with high pressure building in on Monday and Tuesday.

AVIATION /12Z Thursday THROUGH Monday/

Fog will burn off over the next 1 to 2 hours, but lingering low to mid-level clouds will keep MVFR cigs in place at most terminals through early afternoon before scattering out to VFR for the rest of the afternoon and evening. Showers in southwest Ohio could get as far north as KFDY this evening and tonight, but there will be a sharp cut off, and confidence is increasing that this will avoid the other terminals. Could be close for KMFD, but left out of the TAF. Otherwise, we will need to monitor the extent of fog formation again tonight, so started to bring in MVFR to IFR visibilities to the typical terminals.

Light and variable winds early this morning will become W to NW at 5-10 knots by late morning through the evening before turning light S tonight.

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.