textproduct: Cleveland

WHAT HAS CHANGED

No significant changes to the forecast with this update.

KEY MESSAGES

1) A few rounds of showers and thunderstorms are expected late tonight through Friday night with a chance for a few strong storms east of I-71 Thursday 1 - 8 PM.

2) Heat and humidity returns next week with heat indices possibly exceeding 100 degrees, especially in Northwest Ohio.

DISCUSSION

KEY MESSAGE 1... Low pressure moves into the Great Lakes region tonight with residual convection moving in from the northwest late tonight through Thursday morning. This will mainly be rain showers with a few embedded storms.

Additional convection will develop Thursday afternoon, mainly east of I-71. Sufficient instability and deep-layer shear will be present for marginally organized convection during the afternoon with a few strong to severe storms. Severity will likely depend on prevalence of morning convection.

Another low moves up from the southwest, with an additional round of showers and thunderstorms Friday through Saturday morning. Model guidance has trended later with precipitation onset on Friday, and there is a chance that most of Friday is dry. Precipitation is most likely for southern counties.

KEY MESSAGE 2... An upper-level ridge builds into the eastern CONUS, with heat and humidity building into the local region next week. The latest NBM has Tuesday and Wednesday as the hottest days of the week with >50% probability of 90 degrees and heat indices > 100 degrees. There are very low probabilities of thunderstorms each day (around 10- 30%), greater towards the east and best chance is on Wednesday.

AVIATION /18Z Wednesday THROUGH Monday/

VFR across the TAF sites this afternoon with primarily VFR to persist through the TAF period. Rain showers will be moving east into the area this evening and overnight. The heaviest rain may impact TOL with brief IFR vsby drops and have introduced a tempo group. Otherwise, rain showers should remain light, resulting in mainly VFR vsbys. Thunder chances also remain low and thus, have not included tsra or vcts at this time, though they may need to be introduced in the next TAF package, particularly at sites east of the I-77 corridor.

Winds are generally light and favoring a west to southwest direction this afternoon, around 5 knots. A lake breeze has developed and is slowly moving south this afternoon, impacting CLE/ERI with north to northwest flow of 7 to 10 knots. Winds will shift towards the south, then southwest tonight into Thursday, 7 to 10 knots.

Outlook...Non-VFR possible in scattered showers and thunderstorms Thursday afternoon and evening, particularly east of the I-77 corridor where a few stronger wind gusts are possible. Non- VFR possible again in showers and thunderstorms Friday afternoon and evening, mainly south of the I-90 corridor.

MARINE

With the exception of some stronger wind gusts associated with thunderstorms Thursday afternoon and evening, particularly across the eastern basin of Lake Erie, generally quiet marine conditions are expected through the weekend. Winds will shift towards the south to southwest on Thursday, 10 to 15 knots, becoming north to northeast behind a cold front on Friday into Saturday, 10 to 15 knots. Onshore, northeast flow will then continue through Sunday, around 10 knots.

CLE WATCHES/WARNINGS/ADVISORIES

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