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 /00Z Thursday THROUGH Monday/

Multiple rounds of showers are likely across the area through the TAF period. Light rain will move east across the area late tonight into early Thursday morning, although it appears that the best opportunity for non-VFR (most likely MVFR) conditions will be at KTOL between roughly 03Z and 07Z. Most of the showers will exit to the east by late morning Thursday, although scattered showers and perhaps a few thunderstorms may develop near KCLE/KMFD during the afternoon and move east into early evening. Confidence in the placement/coverage/timing of showers/storms is low for Thursday afternoon so opted for VCSH with PROB30 groups and will make adjustments as confidence increases in subsequent updates. Any storms Thursday could produce non-VFR conditions and gusty winds, best chance from KCAK to KYNG and locations southeast.

Light winds are expected tonight with south/southwest winds to 6 to 12 knots and gusts up to 20 knots expected during the day Thursday. Winds at western terminals will likely become a bit more westerly by late afternoon.

Outlook...Non-VFR possible in lingering showers early Thursday night, mainly at KCAK/KYNG. 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.