Strong storms evolved with a the passage of an upper-level trough and its associated cold front. Storms developed over western Pennsylvania just on the windward side of the mountains.
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.
Strong storms evolved with a the passage of an upper-level trough and its associated cold front. Storms developed over western Pennsylvania just on the windward side of the mountains.
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 May 29, 12:38 AM EST, 47 minutes earlier.
Area Forecast Discussion National Weather Service Pittsburgh PA 138 AM EDT Fri May 29 2020 .SYNOPSIS... Severe storms are possible this afternoon with the passage of a cold front. && .NEAR TERM /THROUGH TODAY/... A cluster of showers and storms is currently moving through eastern Ohio/southwestern PA as a shortwave advances north. Based on surface observations and satellite imagery, storms are quickly losing intensity as they enter a more stable environment. A quick 0.25 to 0.40 inches of rain may accumulate south of Pittsburgh. Showers/storms will fizzle out before reaching I-80 an hour or two before sunrise. After sunrise an upper-level trough and its associated cold front are expected to be in the vicinity of Indiana. With roughly 900 to 1100 J/kg CAPE available late morning and weak ascent, pre-frontal showers and storms will form across eastern Ohio and western PA and move through the mean flow of the atmosphere (southwest to northeast). By early afternoon, a disorganized squall line is expected for form west of our region and advance east. Once the trough and cold front become completely in phase with each other, strong storms are anticipated to develop and continue into the evening. By midnight, showers and storms will exit to our east as the cold front moves through central PA. && .SHORT TERM /TONIGHT THROUGH 6 PM SATURDAY/... With low-level residual moisture and prevailing NW flow (i.e. cold advection) expected early Saturday morning, a low stratus deck/some fog will form before sunrise across the region. A weak shortwave advancing across Lake Erie may produce scattered rain showers briefly Saturday afternoon. High pressure building over the Great Lakes will return quiet, dry weather Saturday evening. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... A meridional upper level pattern will remain in place to begin the long term period Saturday night. The deep trough over New England will slow nudge east as the stout ridge over the central CONUS moves east. This will bring a period of dry weather for the next several days. At the surface, high pressure moving in from the northwest will usher is a much cooler air mass with max temps roughly 10 degrees below normal for highs on Sunday, followed by lows dropping into the lower 50s and even upper 40s for lows. The next chance for precip will arrive on Wednesday with a strong shortwave riding over the ridge into the forecast area. This will keep unsettled weather over the area from Wed through Thursday next week. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... VFR expected through the majority of the period with showers and storms late afternoon / early evening with a crossing cold front. .Outlook... High pressure will result in VFR this weekend outside of patchy early morning fog. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...None. OH...None. PA...None. WV...None. &&
Hazardous Weather Outlook National Weather Service Pittsburgh PA 212 AM EDT Fri May 29 2020 MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023- 029-031-073>076-WVZ001>004-012-021-509>514-300615- 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- 212 AM EDT Fri May 29 2020 This Hazardous Weather Outlook is for western Maryland, east central Ohio, northwest Pennsylvania, southwest Pennsylvania, western Pennsylvania, northern West Virginia and the northern panhandle of West Virginia. .DAY ONE...Today and tonight. Severe storms are possible this afternoon and will continue into the evening with the passage of a cold front. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
The Pittsburgh radar (KPBZ), 65 km away, was scanning. The volume nearest the first event began at 06:23 UTC.
12 thunderstorm wind. Local standard time, as filed.
A trained spotter reported multiple trees down.
A COOP Observer reported multiple large trees down in Loyalhanna Lake Parking Lot.
Several trees down; information via social media.
A large tree down near 4th street; information via social media.
Tree down in Connoquenessing township; information provided via social media.
Many trees reported down near an elementary school in Connoquenessing Twp; information provided via social media.
A 911 Call Center reported multiple trees and wires down.
Trees snapped; information provided via social media.
A local resident reported several trees down.
A tree was reported down via social media.
A 911 Call Center reported trees down.
A 911 Call Center reported several trees down.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2020Every state in 2020This day in weather historyWarnings in Pennsylvania, May 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: 891833, 891834, 891835, 891836, 891837, 891839, 891841, 891842, 891843, 891844, 891845, 891846.