An occluded surface low meandered near the eastern shore of Lake Superior during the late morning through early evening of the 12th. Simultaneously, the trailing cold front swept southeastward from southeastern Lower MI and northern IN to central Lake Erie and north-central/west-central portions of OH.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS CLE wrote it up.
An occluded surface low meandered near the eastern shore of Lake Superior during the late morning through early evening of the 12th. Simultaneously, the trailing cold front swept southeastward from southeastern Lower MI and northern IN to central Lake Erie and north-central/west-central portions of OH. Multiple multicell and supercell thunderstorms occurred along and ahead of the cold front in northern OH. These storms produced severe hail, damaging convective gusts, and two tornadoes in a warm sector comprised of moderate to strong MUCAPE and effective bulk shear, respectively, mixed-layer lifting condensation levels near 750 to 1500 meters AGL, and strong surface-based effective storm-relative helicity near 150 meters squared per second squared.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Cleveland, OH wrote its last area forecast discussion before the first event at Aug 12, 9:19 AM EST, 2 hours 33 minutes earlier.
Area Forecast Discussion National Weather Service Cleveland OH 1019 AM EDT Sat Aug 12 2023 .SYNOPSIS... Low pressure centered of Lake Superior will continue to drift northeast today, moving a cold front east this evening into tonight. This boundary will stall across the Ohio River Valley for Sunday. Another low pressure is expected to move east through the Great Lakes region Monday into Tuesday. High pressure settles over the area by midweek. && .NEAR TERM /THROUGH SUNDAY/... Current area of concern is the convection that has developed across the southern shore of Lake Michigan. It's possible that this convection fills in and moves east over the next few hours, reaching NW OH by early afternoon. In general, high resolution guidance has not been performing well with this activity in addition to the convection over southern Michigan, so will most likely need to rely on mesoscale features until models get a better handle on what is currently unfolding. Overall, not a ton of changes were needed with this update besides adjusting PoPs for early this afternoon; expect precipitation chances to quickly ramp up across north-central Ohio early this afternoon with storms quickly progressing across the CWA through early evening. Latest mesoanalysis still indicates that the greatest instability and chance of severe weather will lie east of I-75 and especially in eastern zones where there will be more time for diurnal destabilization and less cloud cover. The 12Z sounding from PBZ indicates mid-level dry air, which should aid in the potential for damaging wind gusts. Damaging wind gusts, large hail, and possibly a few tornadoes will be the main threats at the start of the event, however the HREF suggests that updraft helicity values will enhance roughly from Lake Erie across northeastern Ohio and into northwestern Pennsylvania this afternoon. If this suggestion is correct, this area will need to be monitored for rotating updrafts and a locally higher large hail/tornado threat. The atmosphere will be pretty juicy so rainfall rates will likely be efficient. Fortunately, it appears that storms will be progressive, but will need to monitor potential for training storms. Previous Discussion... Scattered showers and thunderstorms continue to move east across the area this morning as a shortwave trough pushes east of the area. Plenty of moisture, coupled with a narrow vort max and LLJ over the area has been the primary source maintaining these thunderstorms, but as these features shift east over the next couple hours, all shower activity should gradually cease. With warm cloud depths near 12kft and PWAT values near 1.5 inches, the primary threat with lingering storms is heavy rainfall which may lead to localized flooding concerns. As discussed above, Saturday morning much of the area should see a break in precipitation and even possibly some peaks of sunshine. These morning conditions will be key in how the severe weather potential evolves for Saturday afternoon. Models continue to suggest the potential of strong to severe storms across the area, especially for areas along and east of I77. Initiation is trending to be near the southern shore of Lake Erie in far NE OH/NW PA as a convergent boundary provides enough lift to get things going. Modeled soundings suggest CAPE values climbing to 1500-2000 J/kg by 18Z with shear values of 40-50 knots. These conditions coupled with support from a LLJ and upper level short wave trough will support supercell potential. These storms will come with all hazards, but the primary threat will be strong, possibly damaging, wind gusts. In addition, with a colder layer aloft and strong updrafts possible, large hail will also be a concern, especially in the strongest storms. There remains a non-zero chance of tornadoes as well with SRH values in the 0-1 km layer approaching 100 m2/s2 over the area. The best potential for any tornado development will be across NE OH and NW PA, however that doesn't mean they cannot happen elsewhere. The best timing for storm development remains between 2PM to 7PM today. SPC has highlighted this threat in the Day 1 Convective Outlook. Much of the CWA is in a Slight Risk, however an Enhanced Risk does clip Mahoning and Trumbull Counties in OH and Crawford County in PA. In addition to the severe threat, there is also a hydro threat as well. PWAT values are expected to increase with the southwest flow ushering more moisture in, peaking at 1.8-2 inches in the afternoon. These high PWATs coupled with a warm cloud layer near 10kft will again produce efficient, heavy rainfall across the area. Much of the area on Friday received heavy precipitation with passing thunderstorms, with some local areas getting close to 4 inches of rainfall. This initial rainfall has saturated the surface in some locations, which may lead to additional flooding concerns this afternoon. These concerns have been highlighted by WPC in a Day 1 Marginal Risk of Excessive Rainfall. Moral of the story, the atmosphere will be primed for severe weather potential today, so it will be important to have multiple ways of receiving warnings. This evening into the overnight hours, a cold front will move east across the area, settling south of the area as a stationary boundary for much of Sunday. This will provide a period of dry conditions before another low impacts the area in the short term period. High temperatures today and tomorrow will climb into the low to mid 80s, with overnight lows falling into the low 60s. Dewpoints in the 70s today will make for very humid conditions and heat index values approaching the mid to upper 80s. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/... Upper low digs into the Great Lakes with a potent surface low pressure system tracking through the region. First signs of this come Sunday night with 305K isentropic lift/warm front from the southwest, and ramp POPs up after 06Z Monday to account for this. Two distinct areas of low pressure with this surface system, and the one further south will be critical for the area in terms of its track/location. NAM, an outlier, currently pushes it ENE, south of the CWA, while other operational models send it in the same direction, more along the lakeshore. If the NAM solution is correct, that would likely keep the low level jet south of the area, and thus keep much of the severe potential in that area. Further north, the CWA becomes more of a favorable area for severe potential Monday. Cold front will track quickly through by Monday night, with a secondary cold front/thermal trough early Tuesday. 850mb temps get knocked back to the lower teens, and could get some lake effect showers developing in the northwest flow following the system. Upper trough will be the last of the system to exit late Tuesday. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... High pressure and largely dry for the long term with a possible cold front approaching for the end of next week, the only chances for rain in the extended. Still looking at a period without much in the way of temperature extremes, but will need to watch beyond the extended as a stout upper level ridge possibly begins to build over the lower Ohio Valley. && .AVIATION /12Z Saturday THROUGH Wednesday/... Primarily VFR conditions are being observed across the area this morning, although there is some isolated patches of low stratus/fog that is reducing conditions briefly to MVFR. The only terminal at this time being impacted is KYNG, but with the sun on the horizon things should rebound back to VFR pretty quick. This afternoon is the primary concern with this TAF period as the chance of strong to severe storms exists from approximately 17Z to 22Z, extending to near 02Z Sunday for eastern terminals. During these storms, conditions will likely be reduce to MVFR visibilities with gusty winds and hail possible. Due to lack of confidence in the exact timing and extent of these storms, opted to keep optimistic MVFR conditions in the TEMPO this afternoon, although wouldn't be surprised to see IFR conditions sneak in within the strongest storms. Winds in general will be from the southwest at 10-15 knots with locally elevated gusts in storms. Late this evening a cold front will push southeast across the area, stalling across the Ohio River Valley for much of the day Sunday. This will allow for a period of dry conditions to return and allow winds to become light and variable overnight. This has the potential to cause patchy fog again, but only opted to mention it in KMFD, KCAK, and KYNG where confidence in reduced visibilities is highest. This potential may extend to other terminals and will be dependent on the evolution of weather today. Outlook...Non-VFR likely on Monday in showers and thunderstorms. Non-VFR may persist into Tuesday, especially across Northeast Ohio and Northwest Pennsylvania. && .MARINE... Southwest winds 10-20kts today become northwesterly tonight behind a passing cold front 10-15kts with wave heights 1-3ft. Winds become variable Sunday into Sunday night less than 10kts, finally turning southeasterly early Monday at 10-15kts. Another cold front pushing through later Monday brings winds around to the west southwest 15- 25kts Monday night, and then northwesterly Tuesday 15-20kts with wave heights becoming 3-5ft. Winds return to a southerly fetch after Wednesday. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && SYNOPSIS...Campbell NEAR TERM...Campbell/Maines SHORT TERM...26 LONG TERM...26 AVIATION...Campbell MARINE...26
Hazardous Weather Outlook National Weather Service Cleveland OH 353 AM EDT Sat Aug 12 2023 LEZ061-142>149-162>169-130800- Ripley to Buffalo NY extending from 5NM off shoreline to US- Canadian border-Maumee Bay to Reno Beach OH- Reno Beach to The Islands OH-The Islands to Vermilion OH- Vermilion to Avon Point OH-Avon Point to Willowick OH- Willowick to Geneva-on-the Lake OH-Geneva-on-the-Lake to Conneaut OH- Conneaut OH to Ripley NY- Detroit River Lt. to Maumee Bay OH to Reno Beach OH beyond 5NM offshoreline to US-Canadian border- Reno Beach to The Islands OH beyond 5NM off shoreline to US- Canadian border- The Islands to Vermilion OH beyond 5 nm off shoreline to US- Canadian border- Vermilion to Avon Point OH beyond 5 nm off shoreline to US- Canadian border- Avon Point to Willowick OH beyond 5 nm off shoreline to US- Canadian border-Willowick to Geneva-on-the- Lake OH beyond 5NM off shoreline to US-Canadian border-Geneva-on-the- Lake to Conneaut OH beyond 5 nm off shoreline to US-Canadian border- Conneaut OH to Ripley NY beyond 5 nm off shoreline to US- Canadian border- 353 AM EDT Sat Aug 12 2023 This Hazardous Weather Outlook is for Lake Erie. .DAY ONE...Today and tonight. Isolated strong to severe thunderstorms are possible this afternoon and evening. Damaging winds and large hail are the main weather hazards. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Hazardous weather is not expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. OHZ003-006>014-017>023-027>033-036>038-047-089-PAZ001>003-130800- Lucas-Wood-Ottawa-Sandusky-Erie-Lorain-Cuyahoga-Lake-Geauga- Ashtabula Inland-Hancock-Seneca-Huron-Medina-Summit-Portage-Trumbull- Wyandot-Crawford-Richland-Ashland-Wayne-Stark-Mahoning-Marion-Morrow- Holmes-Knox-Ashtabula Lakeshore-Northern Erie-Southern Erie- 353 AM EDT Sat Aug 12 2023 This Hazardous Weather Outlook is for north central Ohio, northeast Ohio, northwest Ohio and northwest Pennsylvania. .DAY ONE...Today and tonight. Scattered strong to severe thunderstorms are possible this afternoon and evening. Damaging winds and large hail are the main weather hazards, although a tornado cannot be ruled out. Localized flooding with heavy rain is also possible. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Hazardous weather is not expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
Special Weather Statement
National Weather Service Cleveland OH
1154 AM EDT Sat Aug 12 2023
OHZ017-018-027-121700-
Seneca OH-Wyandot OH-Hancock OH-
1154 AM EDT Sat Aug 12 2023
...A strong thunderstorm will impact portions of southwestern Seneca,
northern Wyandot and southern Hancock Counties through 100 PM EDT...
At 1154 AM EDT, Doppler radar was tracking a strong thunderstorm near
Bluffton, moving east at 50 mph.
HAZARD...Winds in excess of 40 mph and penny size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Findlay, Tiffin, Bluffton, Arlington, Sycamore, Rawson, Vanlue, New
Riegel, Carey, Mount Blanchard, Wharton, Jenera, Mount Cory, Bascom
and Williamstown.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
&&
LAT...LON 4119 8319 4099 8309 4099 8311 4093 8311
4082 8356 4082 8388 4095 8388
TIME...MOT...LOC 1554Z 248DEG 43KT 4084 8390
MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPH
GaruckasSpecial Weather Statement
National Weather Service Cleveland OH
1244 PM EDT Sat Aug 12 2023
OHZ011>013-121730-
Geauga OH-Lake OH-Cuyahoga OH-
1244 PM EDT Sat Aug 12 2023
...A strong thunderstorm will impact portions of southwestern Geauga,
northeastern Cuyahoga and southwestern Lake Counties through 130 PM
EDT...
At 1244 PM EDT, Doppler radar was tracking a strong thunderstorm over
Cleveland, moving east at 40 mph.
HAZARD...Winds in excess of 40 mph and penny size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Cleveland, Chardon, Euclid, Cleveland Heights, Solon, Warrensville
Heights, South Russell, Highland Hills, Chesterland, Garfield
Heights, Shaker Heights, Maple Heights, South Euclid, Mayfield
Heights, East Cleveland, Lyndhurst, University Heights, Wickliffe,
Beachwood and Bedford Heights.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
&&
LAT...LON 4160 8117 4137 8116 4143 8171 4146 8172
4149 8172 4153 8167 4153 8166 4156 8160
4159 8153
TIME...MOT...LOC 1644Z 268DEG 33KT 4148 8167
MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPH
SullivanThe Cleveland radar (KCLE), 28 km away, was scanning. The volume nearest the first event began at 16:52 UTC.
18 thunderstorm wind, 8 hail, 2 tornado. Local standard time, as filed.
Numerous trees downed in and near Cleveland Heights.
Small tree snapped in Beachwood.
Several trees downed in and near Bascom.
A brief EF1 tornado with estimated peak winds of 90 mph occurred just south of the intersection of OH-309 and Dry Lane Road North in the La Rue area. As the tornado moved east-northeastward, it caused damage at a residential property along Dry Lane Road North. A portion of an outbuilding's roof was torn-off and several trees were damaged.
Several trees and power poles downed in Castalia.
Hail up to golf ball-size near the intersection of Fox Road and Hayes Avenue (OH-4), between Sandusky and I-90.
Several power poles downed near intersection of Fox Road and Hayes Avenue (OH-4), between Sandusky and I-90.
Hail up to golf ball-size near the intersection of OH-2 and OH-4 on the SSW side of Sandusky.
Windows blown-out and TV antenna downed at residence near the intersection of OH-2 and OH-4 on the SSW side of Sandusky.
Several large trees uprooted and/or snapped along Birchwood Drive in Sandusky South.
Several trees downed along OH-61 about one-mile north of Plymouth.
Trees downed along Cedar Point Drive.
Couple of trees downed about three-miles WNW of Galion.
Hail up to quarter-size about one-mile ENE of Lexington.
A couple of trees downed at intersection of Mansfield-Lucas Road and Washington-North Road, about three-miles WNW of Lucas.
Hail up to quarter-size in Perrysburg.
A downed tree limb punctured the roof and ceiling of a residence in Perrysville.
An EF0 tornado with estimated peak winds of 70 mph occurred on the southeastern outskirts of Nashville. This tornado began along Township Road 501, just south of OH-39 and ended just northeast of the intersection of Township Roads 51 and 259. As the tornado tracked southeastward, it uprooted or snapped trees and other trees had their tops sheared-off. No structural damage was observed.
Tree downed in Munson Township.
Hail up to golf ball-size in Edinburg.
Tree down in Burton.
Roof damage to historical building in Palmyra.
Hail up to ping pong ball-size in Palmyra.
Hail up to half dollar-size in Craig Beach.
Hail up to golf ball-size in Lake Milton.
Tree downed onto house about two-miles south of Austintown.
Several trees downed in Poland.
Several trees downed about two-miles east of Perrysville.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Ohio in 2023Every state in 2023This day in weather historyThe tornado archive for Ohio, 2023Warnings in Ohio, August 2023
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1146502, 1146505, 1146493, 1146364, 1146507, 1146521, 1146525, 1146516, 1146518, 1146538, 1146540, 1146534, 1146541, 1146542, 1146544, 1147411, 1147412, 1146440, 1147416, 1147415, 1147417, 1147418, 1147419, 1147420, 1147421, 1147422, 1147423, 1154867.