Widespread showers and isolated storms moved across Pennsylvania as surface low pressure passed over western Ohio. The environment was moist and had moderate wind shear.
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.
Widespread showers and isolated storms moved across Pennsylvania as surface low pressure passed over western Ohio. The environment was moist and had moderate wind shear. Low levels had weak steerage flow that supported flooding.
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 31, 1:29 PM EST, 18 minutes earlier.
Area Forecast Discussion National Weather Service Pittsburgh PA 229 PM EDT Tue Jul 31 2018 .SYNOPSIS... Daily chances for showers and storms are expected through the week with increased moisture and passage of a slow-moving low pressure system. && .NEAR TERM /THROUGH TONIGHT/... A shortwave trough responsible for ongoing convection will help sharpen the warm front that is straddling the forecast area. North of the frontal boundary, broad convective coverage with light-moderate rain can be expected. To the boundary's south, a moist, unstable warm sector will support semi-organized convection in a moderate-shear, moist environment. Given warm-sector storms, the combination of low LCL, enhanced low-level CAPE and broad hodographs with increasingly-favorable critical angle will favor rotating storms capable of a tornado or two and damaging wind gusts during the afternoon. Any afternoon convection will shift ewd tonight and decay with loss of heating, but showers and storms will increase in coverage early Wed morning and begin spreading nwwd with time. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... A stagnant upper-level ridge in the wrn CONUS and the Bermuda High to the east will maintain a trough in the central CONUS thru the next couple of days. Today's surface low will not migrate far Wed and Thu, and its associated cold front advancing across the OH Valley will maintain chances for showers/storms for much of Wed before diminishing in coverage on Thu. Temperature should be near or slightly below seasonal average (in the lower 80s) Wed-Fri owing to persistent cloud cover. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... The unsettled pattern continues. There are still enough differences in model runs to maintain a forecast of daily shower/storm chances following a diurnal cycle. So far, Saturday appears to be the drier day of the weekend compared to Sunday. Temperature will climb to slightly above seasonal average as heights and thicknesses increase. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... Large area of rain with embedded thunderstorms will spread eastward across the PA and WV terminals over the next several hours. By and large, thunderstorm coverage will be focused HLG- MGW with mainly a steady rain further north with some convective enhancement. VFR ceilings generally prevailing through the rain, with localized IFR visibilities in the heavier showers (LIFR visibilities briefly possible MGW 1930-21Z. Behind the precipitation edge later this afternoon, widespread MVFR to IFR stratus has developed and is presently expected to continue through the overnight hours. Areas of fog are also possible before another axis of rain spreads in tomorrow morning. Winds will be light but erratic in direction, with an overall east to southeast tendency, becoming variable toward 12Z. OUTLOOK... Periodic restrictions are likely this week with persistent moist southerly flow and multiple crossing disturbances. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...None. OH...None. PA...None. WV...None. && Kramar
Hazardous Weather Outlook...UPDATED National Weather Service Pittsburgh PA 238 PM EDT Tue Jul 31 2018 MDZ001-OHZ057>059-068-069-PAZ021-029-031-073>076-WVZ002>004-012-021- 509>514-011845- Garrett-Muskingum-Guernsey-Belmont-Noble-Monroe-Allegheny-Washington- Greene-Westmoreland-Westmoreland Ridges-Fayette-Fayette Ridges- Brooke-Ohio-Marshall-Wetzel-Marion-Monongalia- Ridges of Eastern Monongalia and Northwestern Preston-Preston- Eastern Preston-Western Tucker-Eastern Tucker- 238 PM EDT Tue Jul 31 2018 This Hazardous Weather Outlook is for western Maryland, east central Ohio, southwest Pennsylvania, northern West Virginia and northern panhandle of West Virginia. .DAY ONE...This Afternoon and Tonight. A few strong to severe thunderstorms capable of damaging wind gusts and an isolated tornado will be possible this afternoon. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Heavy rain from showers and thunderstorms could produce localized flash flooding on Wednesday. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. OHZ039>041-048>050-PAZ007>009-013>016-020-022-023-WVZ001-011845- Tuscarawas-Carroll-Columbiana-Coshocton-Harrison-Jefferson-Mercer- Venango-Forest-Lawrence-Butler-Clarion-Beaver-Armstrong-Indiana- Hancock- 238 PM EDT Tue Jul 31 2018 This Hazardous Weather Outlook is for east central Ohio, northwest Pennsylvania, west central Pennsylvania, western Pennsylvania and northern West Virginia. .DAY ONE...This Afternoon and Tonight. No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
The Pittsburgh radar (KPBZ), 75 km away, was scanning. The volume nearest the first event began at 18:47 UTC.
2 thunderstorm wind, 1 flash flood. Local standard time, as filed.
The local 911 call center reported that a tree fell onto a parked car in a mobile home park. No injuries were reported.
The local emergency manager reported that several trees were down and blocking the road around Ridge Street and McNeely Road in Jefferson Township.
Flooding reported near New Salem VFD. Flooding in McClellandtown hair salon.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2018Every state in 2018This day in weather historyWarnings in Pennsylvania, July 2018
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: 774712, 774713, 774501.