Diurnally-driven thunderstorms developed along a stationary boundary on August 13th, with an isolated instance of wind damage reported from downburst wind in Washington County.
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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.
Diurnally-driven thunderstorms developed along a stationary boundary on August 13th, with an isolated instance of wind damage reported from downburst wind in Washington County.
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 13, 3:59 PM EST, 2 hours 36 minutes earlier.
Area Forecast Discussion National Weather Service Pittsburgh PA 459 PM EDT Thu Aug 13 2020 .SYNOPSIS... Daily afternoon rain chances are expected through the weekend with the best chance for areawide showers and storms on Saturday. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... As a shortwave trough quickly propagates eastward, the remaining mechanism for convective initiation will be outflow boundaries from previous thunderstorms. These boundaries are traveling westward, and will continue to allow for development until sunset. Low level lapse rates are about 8.5 C/KM, but with little to no wind shear until nearly 25,000 feet. Thunderstorms this afternoon are struggling to reach that threshold, but if they do and they maintain organization aloft, gusty winds and small hail are possible. Showers are training in nature as they move parallel to both the outflow boundary and shortwave aloft. This has allowed for over an inch of rain to fall in spots, but generally with lack of sustainment, flooding issues are not widely anticipated. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/... Diurnal convection is expected once again on Friday as low pressure builds to the southwest of the Ohio Valley. This will allow for isolated thunderstorms, but widespread severe thunderstorms are not foreseen. Scattered coverage of showers and thunderstorms is expected this weekend as the aforementioned low propagates eastward. However, the developing polar jet will begin to have an influence as cooler temperature aloft and a low undergoing cyclogenesis will allow for a surface cold frontal passage to prompt more precipitation, and a change in temperature pattern to slightly below normal late this weekend. && .LONG TERM /MONDAY THROUGH THURSDAY/... High pressure and a relaxed height pattern will support dry conditions through early week. && .AVIATION /21Z THURSDAY THROUGH TUESDAY/... Brief restrictions will continue when isolated showers and thunderstorms develop near terminals this evening. Cloudy skies will inhibit fog formation for early Friday, but the afternoon will again feature isolated thunderstorms which will prompt restrictions accordingly. .Outlook... Restrictions will be possible as widespread precipitation is likely for the weekend. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...None. OH...None. PA...None. WV...None. &&
Hazardous Weather Outlook National Weather Service Pittsburgh PA 307 AM EDT Thu Aug 13 2020 OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023-029- 031-073>076-WVZ001>004-012-021-509>511-140715- 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- 307 AM EDT Thu Aug 13 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. No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. MDZ001-WVZ512>514-140715- Garrett-Eastern Preston-Western Tucker-Eastern Tucker- 307 AM EDT Thu Aug 13 2020 This Hazardous Weather Outlook is for western Maryland and northern West Virginia. .DAY ONE...Today and tonight. Slow moving thunderstorms could result in isolated areas of localized flooding today. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. 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 Pittsburgh PA 545 PM EDT Thu Aug 13 2020 PAZ021-029-132200- Washington-Allegheny- 545 PM EDT Thu Aug 13 2020 ...A STRONG THUNDERSTORM CAPABLE OF PRODUCING SMALL HAIL...GUSTY WIND AND HEAVY RAIN WILL AFFECT NORTH CENTRAL WASHINGTON AND SOUTHWESTERN ALLEGHENY COUNTIES... At 545 PM EDT, a strong thunderstorm was located over Scott Township, or over Mount Lebanon. the storm is nearly stationary. Wind gusts up to 45 mph and small hail are possible with this storm. Locations impacted include... Pittsburgh... Mount Lebanon... Bethel Park... McMurray... West Mifflin... Baldwin... Upper St. Clair... Scott Township... Whitehall... South Park Township... Robinson Township... Cecil-Bishop... This includes the following highways... Interstate 79 in Pennsylvania between mile markers 49 and 61. Interstate 376 in Pennsylvania between mile markers 62 and 67. Torrential rainfall also is occurring with this storm and may cause localized flooding. Do not drive your vehicle through flooded roadways. Frequent cloud to ground lightning is occurring with this storm. Seek safe shelter inside a building or vehicle. LAT...LON 4047 8009 4033 7994 4023 8011 4038 8026 TIME...MOT...LOC 2145Z 054DEG 1KT 4038 8008
The Pittsburgh radar (KPBZ), 54 km away, was scanning. The volume nearest the first event began at 23:37 UTC.
1 thunderstorm wind. Local standard time, as filed.
Five trees were reported to be blown down near the intersection of Scenic Drive and South California Drive in West Pike Run Township.
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, August 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: 915043.