Several ingredients were in place for scattered severe thunderstorms on August 8th. An upper shortwave trough embedded in northwest flow crossed the Great Lakes during the day.
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 PBZ wrote it up.
Several ingredients were in place for scattered severe thunderstorms on August 8th. An upper shortwave trough embedded in northwest flow crossed the Great Lakes during the day. Moist west-southwest flow maintained dewpoints in the mid 60s, which in concert with daytime heating, fueled instability. Strengthening mid-level wind contributed to sufficient levels of shear, allowing an organized line of thunderstorms to cross the region in advance of a cold front. Steep low-level lapse rates promoted a damaging wind threat, but low-level shear was insufficient for a tornado threat. The Storm Prediction Center place the region under a slight risk of severe weather for the day.
Thunderstorms began to form in earnest in southeast Ohio around 4 PM, creating wind damage in Columbiana and Noble Counties, along with a large hail report. The storms formed an organized line and swept across southwest Pennsylvania and northern West Virginia through the late afternoon and early evening. Wind damage was mainly confined to Allegheny and Westmoreland Counties, with numerous reports of tree and power line damage.
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 Aug 8, 2:35 AM EST, 1 hour 28 minutes earlier.
Area Forecast Discussion National Weather Service Pittsburgh PA 335 AM EDT Thu Aug 8 2019 .SYNOPSIS... Another round of thunderstorms, some severe, are expected today ahead of a cold front. Drier and cooler weather is indicated for weeks end. && .NEAR TERM /UNTIL THIS EVENING/... Quiet weather continues early this morning with isolated to patchy fog and light/calm sfc winds. An upper shortwave trough embedded in nwly flow is progged to cross the Great Lakes today with potential for scattered strong to severe storms primarily during the afternoon and evening. Moist WSW sfc flow should maintain dewpoints into the mid 60s which, with daytime heating, will fuel instability. Strengthening mid-level winds over the area will contribute to sufficient shear for an organized line of thunderstorms to cross the region in advance of the cold front. With steep boundary layer lapse rates, but rather limited low-level shear/SRH, the primary severe threat will be damaging wind gusts and large hail with low tornado chances. Have included likely to definite PoPs this afternoon as storm chances shift through the region to the southeast and wane into the evening. && .SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/... Rain/storm chances rapidly come to an end this evening with cold frontal passage. Cooler and drier air is expected behind the front which, with building sfc high pressure, will drop daily temperatures to just below seasonal average and maintain dry weather through the weekend. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... Temperatures will moderate back to average early next week as the Southern US ridge expands eastward and flow over our region becomes more zonal. Shortwaves in this flow will return periodic rain chances to the area, with the greatest chances Tuesday into Wednesday with a crossing sfc low. && .AVIATION /07Z THURSDAY THROUGH MONDAY/... VFR is generally expected although patchy MVFR to IFR fog will mar the usual prone ports through dawn. Otherwise, a reinforcing cold front is expected to cross the region tda with tstms and MVFR/local IFR restrictions. Included a prob30 group for the most likely time to see storms. VFR should return after FROPA. Mixing and an increasing pressure gradient ahead of the approaching front should result in gusty WSW wind by late Thu morning. .Outlook... Restrictions are possible with a Mon cold front. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...None. OH...None. PA...None. WV...None. &&
Hazardous Weather Outlook National Weather Service Pittsburgh PA 254 AM EDT Thu Aug 8 2019 MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023- 029-031-073>076-WVZ001>004-012-021-509>514-090700- Garrett-Tuscarawas-Carroll-Columbiana-Coshocton-Harrison- Jefferson OH-Muskingum-Guernsey-Belmont-Noble-Monroe-Mercer-Venango- Forest-Lawrence-Butler-Clarion-Jefferson PA-Beaver-Allegheny- Armstrong-Indiana-Washington-Greene-Westmoreland-Westmoreland Ridges- Fayette-Fayette Ridges-Hancock-Brooke-Ohio-Marshall-Wetzel-Marion- Monongalia-Ridges of Eastern Monongalia and Northwestern Preston- Preston-Eastern Preston-Western Tucker-Eastern Tucker- 254 AM EDT Thu Aug 8 2019 This Hazardous Weather Outlook is for western Maryland, east central Ohio, northwest Pennsylvania, southwest Pennsylvania, west central Pennsylvania, western Pennsylvania, northern West Virginia and northern panhandle of West Virginia. .DAY ONE...Today and tonight. Thunderstorms are likely today with scattered severe storms possible. Primary hazards will be damaging wind gusts and large hail. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Hazardous weather is not expected at this time. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to Standard Operating Procedures.
The Pittsburgh radar (KPBZ), 21 km away, was scanning. The volume nearest the first event began at 09:04 UTC.
13 thunderstorm wind. Local standard time, as filed.
Large branches were blown down according to a National Weather Service employee.
Large branches were blown down according to a National Weather Service employee.
A trained spotter reported that trees were blown down on Baldwin and McMichael Roads.
A trained spotter reported that a tree was downed on Main Street.
A social media user reported that a tree and power lines were down at the intersection of Oliver Way and Lincoln Way.
The county emergency manager reported trees down on Kalamazoo Road and Highberger Road.
The county emergency manager reported that poles and wires were blown down on Ridge Road.
Power lines were blown down on Lock Street, according to the county emergency manager.
The county emergency manager reported that trees were blown down on Brokers Lane.
County 911 officials reported that trees were blown down on Mickanin Road.
The county emergency manager reported that trees were blown down on Mickanin Road.
A tree was blown down on Brownstown Road, according to the county emergency manager.
A member of the public reported that trees and limbs were blown down to the south and southeast of town.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2019Every state in 2019This day in weather historyWarnings in Pennsylvania, August 2019
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: 849484, 849485, 849488, 849489, 849570, 849571, 849572, 849573, 849574, 849575, 853681, 849576, 849577.