A shortwave emerging from the base of a persistent Great Lakes to Gulf of Mexico upper trough supported the development of numerous showers and thunderstorms. One to two inches of rain caused some isolated flooding issues in Clarion County.
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.
A shortwave emerging from the base of a persistent Great Lakes to Gulf of Mexico upper trough supported the development of numerous showers and thunderstorms. One to two inches of rain caused some isolated flooding issues in Clarion 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 3, 7:43 AM EST, 1 hour 32 minutes earlier.
Area Forecast Discussion National Weather Service Pittsburgh PA 843 AM EDT Fri Aug 3 2018 ...UPDATED AVIATION DISCUSSION... .SYNOPSIS... An upper trough will maintain precipitation chances into Saturday, then move east of the region. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Alterations for the 0500 update featured POP adjustments for quicker, albeit light shower, development based on the latest radar and high res. trends. Likely to categorical POPs were maintained as another impulse emerging from the base of the parent, Great Lakes-Gulf Mexico- upper trough will support numerous, to widespread showers today with focus over areas along and east of I-79. No changes were made for the Flash Flood Watch over the ridges. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/... Passage of the aforementioned disturbance is progged to begin the end of the persistent trough pattern as the associated jet streak is forecast to pull the main trough axis eastward, a process which should complete on Saturday as per the latest deterministic and ensemble trends. More widespread convection today will thus give way to more scattered activity on Saturday, with prevalent dry weather anticipated for Sunday as a shortwave ridge builds. The improving insolation and rising heights will also support a warming temperature trend for the weekend. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... Ern CONUS troughing is projected to resume quickly next week so daily rain chances were maintained with temperature at, or slightly below the averages. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... General conditions across the region today will feature mid level VFR ceilings and patchy light rain. However, isolated pockets of heavy showers could reduce visibilities all the way down to low end IFR. The lone exception to this is at DUJ, which is at the southwestern edge of very low stratus and fog which has trended south and west across the central mountains overnight. LIFR conditions are possible for a brief period this morning there and terminals north and east out of the local forecast area. Coinditions should steadily improve from west to east late morning into early afternoon as the axis of rainfall shifts east. MVFR conditions will hold on longest at LBE-MGW-DUJ, perhaps as late as 21Z. Given the widespread rain and very moist conditions, will have to monitor forecast trends for the potential of LIFR fog development tonight into early Saturday, pending the 18Z update. OUTLOOK... Some restrictions will be possible as weak front/upper trough depart Saturday, but VFR should prevail thereafter under high pressure until Monday. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...Flash Flood Watch until 8 PM EDT this evening for MDZ001. OH...None. PA...Flash Flood Watch until 8 PM EDT this evening for PAZ076. WV...Flash Flood Watch until 8 PM EDT this evening for WVZ510>514. &&
Hazardous Weather Outlook National Weather Service Pittsburgh PA 304 AM EDT Fri Aug 3 2018 MDZ001-PAZ076-WVZ510>514-040715- Garrett-Fayette Ridges- Ridges of Eastern Monongalia and Northwestern Preston-Preston- Eastern Preston-Western Tucker-Eastern Tucker- 304 AM EDT Fri Aug 3 2018 ...FLASH FLOOD WATCH IN EFFECT THROUGH THIS EVENING... This Hazardous Weather Outlook is for western Maryland, southwest Pennsylvania and northern West Virginia. .DAY ONE...Today and Tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Flash Flood Watch. .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. OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023-029- 031-073>075-WVZ001>004-012-021-509-040715- Tuscarawas-Carroll-Columbiana-Coshocton-Harrison-Jefferson-Muskingum- Guernsey-Belmont-Noble-Monroe-Mercer-Venango-Forest-Lawrence-Butler- Clarion-Beaver-Allegheny-Armstrong-Indiana-Washington-Greene- Westmoreland-Westmoreland Ridges-Fayette-Hancock-Brooke-Ohio- Marshall-Wetzel-Marion-Monongalia- 304 AM EDT Fri Aug 3 2018 This Hazardous Weather Outlook is for 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. 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.
The Pittsburgh radar (KPBZ), 83 km away, was scanning. The volume nearest the first event began at 14:18 UTC.
2 flash flood, 1 heavy rain. Local standard time, as filed.
County 911 officials reported that North Riverview Drive between Foxburg and Emlenton was flooded in multiple areas.
County 911 officials reported that Sugar Valley Road was completely covered by water.
The county emergency manager reported that 1.54 inches of rain fell in 3.5 hours. Isolated areas of 2 inches likely occurred northeast of St. Petersburg.
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, August 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: 778184, 778185, 780019.