textproduct: Cleveland

WHAT HAS CHANGED

Light showers have expanded north in an arc from Lorain to Youngstown late this afternoon. These showers will tend to dissipate through approximately 7 PM while additional scattered showers are expected across Central Ohio.

KEY MESSAGES

1) Very hot and humid conditions are expected across the region Tuesday through Friday. Preparations should be made now to help mitigate the effects of prolonged heat later this week.

2) Chances of showers and thunderstorms return to the local area Friday and continue into the Holiday Weekend.

DISCUSSION

KEY MESSAGE 1... A pattern change is in store to start the week as a warm front lifts north on Monday and the upper level ridge expands across the Great Lakes Region. An anomalously strong ridge is expected to develop with 500mb heights of 594dm reaching Detroit on Tuesday and Buffalo on Wednesday. Some variability in timing shortwave energy trying to suppress the ridge develops in the models by Thursday, but overall confidence is above normal in a stretch of high heat and humid conditions in the Tuesday to Friday period. Stay tuned for the latest forecast information as a combination of Heat Advisories and Extreme Heat Warnings are likely. See the Climate section below for record highs next week.

The warming trend will get underway on Monday as a warm front lifts north. Can't rule out an isolated shower near or north of the Toledo with the front Monday morning but confidence was not high enough to include in the forecast yet. After that time, southerly flow returns with warm advection pushing 925mb temperatures of up to 26C in Northwest Ohio. With dewpoints reaching the low 70s on Monday in western Ohio, heat index values may reach or exceed 100 degrees along the I-75 corridor. Eastern portions of the forecast area will only experience slightly above normal temperatures on Monday with lower humidity. The heat really becomes established across most of the area on Tuesday as highs reach or exceed 90 with mid to upper 90s in NW Ohio and extending east to Cleveland. The heat will become more oppressive as we experience consecutive days in the 90s through at least Thursday and overnight lows that remain warm, especially closer to Lake Erie.

A strong capping inversion is expected to be in place with 700mb temperatures of 10C or more through Thursday. With generally weak flow, lake breezes are likely to develop and keep temperatures a few degrees cooler along the lakeshore east of Cleveland. Not out of the question to see an isolated thunderstorm or two along the lake breeze by Thursday. Chances of thunderstorms trend upwards by Friday as moisture increases into the region which could impact temperatures.

KEY MESSAGE 2... Confidence in pattern evolution towards the end of the week is low but generally shows the upper level ridge starting to be suppressed to the south. This will likely result in an increase in moisture and scattered showers and thunderstorms heading into the holiday weekend. Timing and favored placement will need to refined over the coming days.

AVIATION /18Z Saturday THROUGH Thursday/

An area of low ceilings remains persistent across portions of the central highlands this evening with cloud heights generally ranging from 1-3kft. These conditions are currently impacting KMFD and KCAK, but may improve to low end VFR at times over the next couple hours. After sunset, models suggest that a low layer of moisture will linger, but there is uncertainty if this will present itself as low stratus or as fog. Opted to maintain the mention of IFR ceilings of 500-800 feet late tonight with reduced visibilities to 2SM for most southern terminals. The exception to this was KFDY which will likely remain MVFR. This forecast is highly dependent on how much clearing the area sees. For terminals along the lakeshore, expect VFR conditions to prevail through this period.

Winds will remain light and variable into tomorrow before a lake breeze develops and terminals along the lakeshore see a NNE wind of 5-10 knots develop. After sunset on Sunday, winds will once again return to light and variable.

Outlook...Non-VFR possible Sunday morning into early afternoon in fog/mist and low ceilings.

MARINE

Weak low pressure moves to the south of Lake Erie today as high pressure will build in across the region this evening from the north. Conditions across the lake will be rather quiet for the next several days with winds out of the northeast at around 10 knots, weakening to 5-10 knots tonight with the high building in. Monday evening, a warm front will move north across the region and winds will shift to be out of the south-southwest and increase to around 10 knots. High pressure builds into the region next week with quiet conditions expected at this time.

CLIMATE

Hotter and more humid weather is expected this Monday 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 06-29 100(1952) 96(1934) 94(2012) 98(1952) 99(1933) 90(2021) 06-30 97(1953) 94(1970) 95(1941) 96(1913) 94(1942) 92(1930) 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)

CLE WATCHES/WARNINGS/ADVISORIES

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