A shortwave trough and its associated surface cold front advanced across the upper Midwest and Great Lakes on July 10th. Conditions were favorable for strong/ severe downburst winds.
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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 PBZ wrote it up.
A shortwave trough and its associated surface cold front advanced across the upper Midwest and Great Lakes on July 10th. Conditions were favorable for strong/ severe downburst winds. HREF models at the time suggested a period of 1500 MUCAPE across the western counties, steep low-level lapse rates, and surface delta theta-e values approaching 20K. Flooding was likely due low shear and PWAT values near 1.5-1.8 inches.
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 Pittsburgh, PA wrote its last area forecast discussion before the first event at Jul 10, 9:10 AM EST, 2 hours 50 minutes earlier.
Area Forecast Discussion National Weather Service Pittsburgh PA 1010 AM EDT Fri Jul 10 2020 .SYNOPSIS... Scattered thunderstorms are expected this afternoon/evening as a cold front approaches. && .NEAR TERM /THROUGH TONIGHT/... A cold front, currently situated in western Indiana, will continue to advance into the Ohio River Valley later today. With another hot day upon us (temps in the low-90s), pre-frontal storms will likely ignite shortly after lunch. With high PW's (over 1.7 inches), steep low and mid- level lapse rates, SBCAPE over 3000 J/kg, and DCAPE ranging between 800 to 1000 J/kg across the region, a few storms may produce damaging wind. The "Wind INDEX" or "WINDEX" on the latest GFS suggests winds 50 to 65 kts may occur under these downbursts. The Weather Prediction Center has maintained a 'Slight' risk for excessive rain across our region; isolated areas hit hard by rain over the last few days may be vulnerable to flash flooding (3hr FFG near the Pittsburgh region is 1.50 to 2.00 inches). Showers and thunderstorms will continue overnight as the center of a low pressure system lingers over Lake Erie. By this time, storms are expected to be non-severe due to the loss of daytime heating. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... By early Saturday morning, the low pressure system mentioned above will swing across I-80 and morph into a weak trough. Scattered showers will continue but thunderstorm chances will be low due heavy cloud coverage should hinder destabilization sufficiently to keep storm strength in check. A brief break in precipitation is expected Saturday night, but another shortwave dipping into the middle Ohio Valley will provide another round of showers and thunderstorms on Sunday. A strong shortwave and a good 850mb moisture feed may provide another soaking rain in some locations. Warm advection will help push temperatures a bit higher during the afternoon, into the mid 80s. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... Continued troughing aloft will keep rain chances and seasonable temperatures in the forecast Sunday night and Monday. Thereafter, troughing over western Canada will help to drive 500mb heights upward across much of the eastern CONUS. Heat will return to our region, with the 90 degree level likely to be breached once again in most areas by Wednesday and Thursday. Rain chances will be limited to mainly isolated diurnal convection. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... VFR is expected with shower and thunderstorm potential increasing mid to late aftn as a trough crosses the Upper Ohio Valley region. Handled the tstm potential with VCTS, and a prob30 for the most likely time of occurrence. Convection will taper off through the evening as instability wanes, though a few showers are still possible as the trough completes its passage. MVFR cigs are then expected late tonight with low level moisture. .Outlook... Periodic restriction and shra/tstm potential is expected through Mon, especially during the aftn/eve, as a series of troughs cross the region. && .CLIMATE... Today is expected to be the last day in the recent streak of high temperatures of 90 degrees or higher at a few climate sites. Here is a summary of the most-recent 90+F stretches at each site where 90 or higher is forecast today: Pittsburgh (7/3-7/10/2020): prior 8-day stretch ended 8/20/1995 Morgantown (7/2-7/10/2020): prior 9-day stretch ended 8/4/1995 Wheeling (7/4-7/10/2020): prior 7-day stretch ended 7/27/2016 The current forecast calls for Zanesville to only reach 89 today. If that forecast is correct, it will end the 90+F streak at six days. That streak length was last reached in July 2012, with the streak actually reaching seven days and ending on July 8th that year. The 90+F run at Dubois ended on Tuesday, as the mercury only got to 89. The streak of 3 days was last matched in 2016, ending on July 25th of that year. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...None. OH...None. PA...None. WV...None. &&
Hazardous Weather Outlook National Weather Service Pittsburgh PA 408 AM EDT Fri Jul 10 2020 OHZ039>041-048>050-057>059-068-069-PAZ007-008-013-014-020-021-029- 031-WVZ001>004-012-021-509-110815- Tuscarawas-Carroll-Columbiana-Coshocton-Harrison-Jefferson OH- Muskingum-Guernsey-Belmont-Noble-Monroe-Mercer-Venango-Lawrence- Butler-Beaver-Allegheny-Washington-Greene-Hancock-Brooke-Ohio- Marshall-Wetzel-Marion-Monongalia- 408 AM EDT Fri Jul 10 2020 This Hazardous Weather Outlook is for east central Ohio, northwest Pennsylvania, southwest Pennsylvania, western Pennsylvania, northern West Virginia and the northern panhandle of West Virginia. .DAY ONE...Today and tonight. Scattered showers and thunderstorms are expected during the afternoon and evening hours. A few storms may approach severe limits, with damaging wind gusts being the primary threat. The stronger storms will also be capable of producing heavy rain and localized flooding. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to Standard Operating Procedures. MDZ001-PAZ009-015-016-022-023-073>076-WVZ510>514-110815- Garrett-Forest-Clarion-Jefferson PA-Armstrong-Indiana-Westmoreland- Westmoreland Ridges-Fayette-Fayette Ridges- Ridges of Eastern Monongalia and Northwestern Preston-Preston- Eastern Preston-Western Tucker-Eastern Tucker- 408 AM EDT Fri Jul 10 2020 This Hazardous Weather Outlook is for western Maryland, northwest Pennsylvania, southwest Pennsylvania, western Pennsylvania and northern West Virginia. .DAY ONE...Today and tonight. No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to Standard Operating Procedures.
Special Weather Statement
National Weather Service Pittsburgh PA
1249 PM EDT Fri Jul 10 2020
OHZ041-101715-
Columbiana-
1249 PM EDT Fri Jul 10 2020
...A STRONG THUNDERSTORM CAPABLE OF PRODUCING SMALL HAIL AND GUSTY
WIND WILL AFFECT NORTHEASTERN COLUMBIANA COUNTY...
At 1249 PM EDT, a strong thunderstorm was located over Columbiana.
the storm is nearly stationary.
Wind gusts up to 45 mph and small hail are possible with this storm.
Locations impacted include...
Salem... Columbiana...
Lisbon... Leetonia...
New Waterford... Rogers...
Guilford Lake State Park...
LAT...LON 4090 8082 4090 8056 4079 8059 4075 8087
4093 8090 4093 8082
TIME...MOT...LOC 1649Z 175DEG 1KT 4086 8072The Pittsburgh radar (KPBZ), 60 km away, was scanning. The volume nearest the first event began at 16:58 UTC.
7 thunderstorm wind. Local standard time, as filed.
A 911 Call Center reported a power pole down in the vicinity of Leetonia.
A local citizen reported numerous trees down and large corn stalks flattened.
The Department of Highways reported a few trees down around Batesville area.
A local citizen reported a large tree snapped in half.
A local citizen reported a large tree down along with power lines.
A 911 Call Center reported trees down.
A large tree fell on a car and garage.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Ohio in 2020Every state in 2020This day in weather historyWarnings in Ohio, July 2020
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: 903810, 903812, 903815, 903817, 903818, 903819, 903820.