textproduct: Cleveland

WHAT HAS CHANGED

There were no major changes with this update. New high temperature records were set at Toledo (99 degrees) and Cleveland (97 degrees) today.

Extended the Extreme Heat Warning for Northern Ohio and Heat Advisory for Northwest Pennsylvania through Friday evening.

KEY MESSAGES

1) Dangerous heat and humidity persist through the end of the week.

2) Daily chances for showers and thunderstorms return Thursday evening onward.

DISCUSSION

KEY MESSAGE 1... Surface high pressure and an accompanying upper level ridge persist across eastern United States. Dangerous heat and humidity continue to impact the region as 850mb temperatures rise to the 20-25C range (99th percentile). Daily maximum temperatures through Friday are expected to rise into the mid to upper 90s accompanied by dew points in the mid 70s. This will lead to maximum heat index values in the 100-110F range through the end of the week. Extended the end time of heat headlines to remain valid through 8 PM Friday. Additional heat headlines may be needed on Saturday if coverage of showers and thunderstorms is lower than expected. With the continued heat and limited overnight relief, the majority of the forecast area remains under Extreme HeatRisk (Level 4 of 4). For people without effective cooling, especially heat-sensitive groups, this level of heat can be deadly.

KEY MESSAGE 2... The pattern turns more unsettled late this week as the upper level ridge begins to breakdown. Increased chances of showers and thunderstorms are expected for the holiday weekend. Confidence in timing, coverage, and placement of showers and storms remains very low Friday into the weekend. Slight chance to chance PoPs are forecast across the region Friday with higher chance to likely PoPs forecast Saturday and Sunday as surface low pressure hangs in the vicinity of the Great Lakes/Ohio Valley region. SPC has placed the entire forecast area in a Marginal Risk (Level 1 of 5) for severe weather on Friday. Will continue to monitor severe weather potential with the next few forecast cycles.

AVIATION /18Z Wednesday THROUGH Monday/

Widespread VFR conditions are expected through this period as a dominant ridge continues to influence the area. There is a brief potential for MVFR ceilings to push north and impact KCAK and KYNG late tonight into Thursday morning, but with low confidence opted to keep this out of the TAF with this update. Winds from the southwest may periodically gust close to 20 knots especially during the afternoon hours, but overall winds will remain from the southwest at 5-10 knots.

Outlook...There is a very low chance of thunderstorms Thursday evening. Greater potential for scattered storms Friday through Sunday, especially during the afternoon and evening hours each day.

MARINE

With high pressure to the south, pleasant marine conditions are expected with southwest flow averaging 10 knots through the period. There could be a lake breeze that develops east of Cleveland each afternoon, which would allow for minor shifts in wind direction and brief 2 ft waves that would be short-lived.

CLIMATE

Very hot and humid weather is expected through Friday. Record warm high temperatures may be challenged. Here are those records for each of our climate stations:

Date Toledo Mansfield Cleveland Akron Youngstown Erie 07-01 98(1931) 98(1931) 95(2002) 97(1931) 96(1931) 94(2018) 07-02 98(2011) 97(1931) 97(1954) 98(1931) 98(1931) 94(1963) 07-03 100(1911) 93(2020) 98(1949) 97(1911) 98(1898) 93(1934) 07-04 100(2012) 96(2012) 98(1990) 99(1911) 99(1897) 99(1990)

CLE WATCHES/WARNINGS/ADVISORIES

OH...Extreme Heat Warning until 8 PM EDT Friday for OHZ003-006>014- 017>023-027>033-036>038-047-089. PA...Heat Advisory until 8 PM EDT Friday for PAZ001>003. MARINE...None.