textproduct: Cleveland

WHAT HAS CHANGED

No significant changes from the previous forecast.

KEY MESSAGES

1) Showers and thunderstorms are likely late Monday through Tuesday. Storms may be strong to severe on Tuesday.

2) Cooler temperatures and patchy wildfire smoke return today with a brief warmup expected Monday into Tuesday. Below normal temperatures return for mid to late week.

DISCUSSION

KEY MESSAGE 1... High pressure will briefly build over the region today through much of Monday before exiting to the east Monday night. The departure of the high will allow a warm front to lift into a region as an unseasonably dynamic low pressure system tracks east to the north of the Upper Great Lakes. A weakening complex of thunderstorms may move southeast into the area late Monday night into early Tuesday morning, which could leave behind boundaries for additional convection development as a strong cold front moves into the area during the day and possibly into Tuesday evening. The dynamic wind field will provide plenty of shear to support organized convection, although there is still uncertainty in instability given the potential for early day showers/storms and residual clouds. Regardless, there is potential for strong to severe thunderstorms at some point on Tuesday, although confidence in the timing/placement of strong storms is still low due to uncertainty in mesoscale features and the trajectory of Monday night's weakening convection. It's possible that the greater severe weather risk will be to the southeast of the local area.

Storms should exit to the east by Tuesday night, although continued upper level troughing could lead to additional lake- enhanced rain showers into Wednesday.

KEY MESSAGE 2... After a period of hot and humid weather, temperatures will be much more comfortable with highs in the mid 70s to lower 80s and dew points in the 50s expected. Tonight's lows will be the coolest in quite some time with widespread 50s anticipated. Northerly flow will bring some wildfire smoke into the area today and possibly into tonight. Conditions may be a bit hazy at times, but impacts to visibilities/air quality will not be as severe as the last several days.

Temperatures will warm up by a few degrees Monday/Tuesday with humidity returning in the warm sector Tuesday. Cloud cover and precipitation may result in cooler temperatures than currently forecast on Tuesday, but as mentioned in the first key message discussion, there is some uncertainty in precipitation timing and placement in addition to cloud cover during the day Tuesday. Cold air advection behind the strong cold front will cause temperatures to fall to below normal values Wednesday/Thursday with temps gradually recovering starting Friday.

AVIATION /12Z Sunday THROUGH Thursday/

Mixed-bag of VFR and MVFR conditions across the TAF sites this morning, associated with pockets of lower vsbys due to wildfire haze/smoke. Anticipate vsbys to gradually improve to VFR by mid- morning, though 6sm haze may linger through much of the day and potentially overnight.

Winds will remain out of the north today, 8 to 10 knots, becoming light and variable this evening. Winds at CLE/ERI may favor a slight southerly direction overnight as a weak land breeze develops.

Outlook...Pockets of non-VFR likely in showers and thunderstorms Monday night through Tuesday. Some thunderstorms Tuesday afternoon and evening may contain strong wind gusts. Residual non-VFR possible on Wednesday on rain showers across the eastern half of the area.

MARINE

Marine conditions will gradually improve across the lake this morning as winds subside to 10 knots or less by the afternoon. The next period of concern for rough marine conditions and marine headlines will be on Tuesday as southwest winds of 15 to 25 knots develop ahead of a cold front. Rough marine conditions will continue through Wednesday as winds shift towards the northwest behind the front, around 20 knots, ushering in waves of 3 to 5 feet. In addition, strong thunderstorm wind gusts are possible across Lake Erie Monday night into Tuesday ahead of the front.

CLE WATCHES/WARNINGS/ADVISORIES

OH...Beach Hazards Statement until 8 AM EDT this morning for OHZ009>012-089. PA...None. MARINE...Small Craft Advisory until 8 AM EDT this morning for LEZ144>148.