textproduct: Cleveland

WHAT HAS CHANGED

No major changes to the forecast.

KEY MESSAGES

1) Daily chances for showers and thunderstorms beginning this afternoon and continuing into the weekend. Highest chances for precipitation will be Tuesday and Thursday afternoon.

2) Summertime heat and humidity enter the region with peak heat index values approaching 100 degrees by mid-week.

DISCUSSION

KEY MESSAGE 1... High pressure exits to the east today as shortwave aloft approaches the region. Showers and isolated thunderstorms will develop this afternoon and evening. There may be an isolated stronger thunderstorm given moderate instability (800-1200 J/kg SBCAPE) and weak deep-layer shear (10-20 knots), though anticipating any storms this afternoon and evening to remain below severe limits.

Coverage in showers and thunderstorms will increase by Tuesday as a warm front lifts across the region during the day. Moderate instability (1000-1500 J/kg SBCAPE) develops with increased deep- layer shear (20-30 knots). The atmosphere will remain moist as PWATs climb to 2 inches and any thunderstorm that develops will be capable of producing heavy rainfall. Will keep an eye on any flooding potential but most of the CWA is in need of a good wetting rain.

There will be periodic daily chances for showers and thunderstorms through the end of the week despite an upper level ridge building overhead. Low confidence in coverage and timing beyond Tuesday depending on the magnitude and placement of the aforementioned ridge. There is a non-zero chance for severe weather on Thursday as machine learning guidance shows a 15-30% probability for severe weather across northern Ohio and Northwest Pennsylvania. SPC has highlighted portions just to the west of the CLE CWA in their extended (Days 4-8) severe outlook for Thursday (June 11).

KEY MESSAGE 2... Anticipate a period of above normal temperatures with hot and humid conditions through the end of the week. Summertime temperatures with afternoon highs in the upper 80s to lower 90s will be coupled with dew points in the upper 60s to lower 70s. Heat indices will also be on the rise through the week with peak heat index values approaching 100F Wednesday and Thursday. Limited overnight relief as overnight lows will settle in the upper 60s to lower 70s. Early season heat is oftentimes more dangerous and can pose a greater risk for heat- related illness. Stay hydrated and take frequent breaks out of the sun and in cooled locations!

AVIATION /06Z Monday THROUGH Friday/

VFR for much of the TAF. Upper level trough moving in from the west late in the TAF period brings convective chances after 23Z for the western terminals, and later further east at MFD. Best way to cover this for now is the PROB30 category with minimal restrictions in place in convection and expect it to be scattered in nature in terms of coverage. Winds easterly become south southeasterly under 10kts.

Outlook...Periods of non-VFR likely in occasional showers and thunderstorms early Tuesday through Friday.

MARINE

Northeast winds 10-20kts today become offshore tonight 10-15kts with wave heights 1-2ft today becoming less than a foot in the nearshore zones tonight into Tuesday. Tuesday night into Wednesday, winds become southwesterly 10-15kts and remain there through Thursday. Wave heights nearshore less than 2ft through that period. Showers and storm possible activity possible beginning tonight through Tuesday.

CLE WATCHES/WARNINGS/ADVISORIES

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