Two waves of severe storms entered the Ohio River Valley on July 13th. The first, was in the early morning hours.
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.
Two waves of severe storms entered the Ohio River Valley on July 13th. The first, was in the early morning hours. Despite the lack of day time heating, instability was available due to warm, moist advection under southwest flow. Vertical wind shear was also available as a trough approached an area of high pressure and a created a pressure gradient.
During the afternoon, warm and unstable conditions prevailed; dew points stayed in the lower 70s. Mean-layer CAPE of 1500-2000 J/kg was able to develop. Due to a gradient between upper high pressure off the east coast and a shortwave trough moving northeast through the Ohio Valley, moderate mid-level flow characterized by 30-40 knots of 0-6km shear prevailed. This allowed storms to organize into multicellular storm clusters and short line segments. Many wind damage reports were received, mainly to trees and power lines, although a few reports of structural damage were also noted.
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 13, 2:16 AM EST, 32 minutes earlier.
Area Forecast Discussion National Weather Service Pittsburgh PA 316 AM EDT Tue Jul 13 2021 .SYNOPSIS... Warm and humid conditions will linger through the week along with daily shower and thunderstorm chances. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Have ramped up PoPs for southern two-thirds of the region early this morning as a weak shortwave drives several clusters of moderate convection northwards. Rapid storm motion near 30kts should preclude flash flooding potential, but these showers and storms continue to be efficient rain-makers. This convection should wane over the next several hours. Upper trough axis across the Midwest will slowly shift eastward today as a weak sfc low crosses into the Great Lakes. This will lift the warm frontal boundary even farther north, edging deeper moisture out of the forecast area. Regardless, daytime heating in the warm sector should once again support scattered showers and thunderstorms this afternoon, though overall coverage is likely to be less than previous days. SPC has maintained a Marginal Risk for severe storms for the area, given an environment that may marginally support damaging wind gusts in stronger storms. Afternoon storms will continue to be efficient rain-makers, but quick storm motion should preclude flash flooding. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... Isolated showers/thunderstorms may linger into the evening and overnight hours, but loss of daytime heating and waning instability will suppress more widespread convective activity overnight. The sharpening upper shortwave trough will cross the area on Wednesday, aiding shower and thunderstorm development once convective temps are reached late Weds morning and afternoon. Timing of best upper support will likely keep the most widespread convection across PA and WV, with lesser extent farther west into OH. More widespread rain and cloud cover should ease high temperatures by several degrees Weds afternoon. Rain chances will diminish Weds night and Thurs as weak mid-lvl ridging briefly builds across the region. However, drier conditions will once again boost high temperatures into the upper 80s for much of the area. && .LONG TERM /FRIDAY THROUGH MONDAY/... The next trough will arrive in the Great Lakes/Ohio Valley region by Friday with a slowly moving cold front eventually crossing on Saturday. Better rain chances should spread across the area Friday morning and afternoon in advance of the front, with rain chances lingering for at least southeast portions of the area into Sunday. Drier weather is expected Monday as high pressure begins to build across the region. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/... Low confidence forecast as current pattern makes it very difficult to pinpoint when a shower or storm will hit a particular port. The pattern would dictate a general VFR forecast with CU developing during daytime heating. Messaging for ra/tsra will have to come once convection begins to develop, really at any time during the forecast period. Surface winds will increase later this morning, with gusts near 20kts possible into the evening hours. .Outlook... Periodic restrictions with showers and storms, mainly during the afternoon and evening hours, will be possible through the week. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. &&
Hazardous Weather Outlook National Weather Service Pittsburgh PA 239 AM EDT Tue Jul 13 2021 OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023-029- 031-073>076-WVZ001>004-012-021-509>514-140645- 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- Higher Elevations of Westmoreland-Fayette- Higher Elevations of Fayette-Hancock-Brooke-Ohio-Marshall-Wetzel- Marion-Monongalia- Ridges of Eastern Monongalia and Northwestern Preston-Preston- Eastern Preston-Western Tucker-Eastern Tucker- 239 AM EDT Tue Jul 13 2021 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. Isolated severe storms are possible today with the threat for damaging wind gusts. Storms may also produce briefly heavy downpours which could lead to localized flooding. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. There is a low probability for widespread hazardous weather. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to Standard Operating Procedures.
Special Weather Statement
National Weather Service Pittsburgh PA
215 AM EDT Tue Jul 13 2021
WVZ004-012-130645-
Marshall-Wetzel-
215 AM EDT Tue Jul 13 2021
...A STRONG THUNDERSTORM CAPABLE OF PRODUCING GUSTY WIND AND HEAVY
RAIN WILL AFFECT NORTHWESTERN WETZEL AND MARSHALL COUNTIES...
At 215 AM EDT, a strong thunderstorm was located near New
Martinsville, moving northeast at 25 mph.
Wind gusts up to 45 mph are possible with this storm.
Locations impacted include...
New Martinsville... Cameron...
Rocklick... Lynn Camp...
Lone Oak... Glen Easton...
Proctor... Beelers Station...
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 3959 8081 3965 8087 3969 8086 3971 8083
3974 8086 3996 8060 3989 8052 3975 8052
TIME...MOT...LOC 0615Z 229DEG 23KT 3968 8079Special Weather Statement
National Weather Service Pittsburgh PA
323 AM EDT Tue Jul 13 2021
PAZ029-130800-
Washington-
323 AM EDT Tue Jul 13 2021
...A STRONG THUNDERSTORM CAPABLE OF PRODUCING GUSTY WIND AND HEAVY
RAIN WILL AFFECT CENTRAL WASHINGTON COUNTY...
At 322 AM EDT, a strong thunderstorm was located near Wolfdale, or
near Washington, moving northeast at 35 mph.
Wind gusts up to 45 mph are possible with this storm.
Locations impacted include...
McMurray... Washington...
Canonsburg... Cecil-Bishop...
Wolfdale... McGovern...
Bentleyville... East Washington...
Houston... Claysville...
Eighty Four... Cokeburg...
This includes the following highways...
Interstate 70 in Pennsylvania between mile markers 6 and 33.
Interstate 79 in Pennsylvania between mile markers 27 and 50.
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 4014 7996 4001 8034 4016 8046 4034 8019
4032 8015 4031 8012
TIME...MOT...LOC 0722Z 239DEG 30KT 4012 8035The Pittsburgh radar (KPBZ), 21 km away, was scanning. The volume nearest the first event began at 07:47 UTC.
41 thunderstorm wind, 2 hail. Local standard time, as filed.
Trees and power lines were downed on Wible Run Road at Hillwood Road.
Trees and power lines were blown down on Bausman Street.
Power lines were blown down on Banksville Road.
Numerous trees were snapped or uprooted, bringing down power lines as well.
In the vicinity of Chartiers, trees and power lines were reported to be blown down.
Trees and power lines were reportedly blown down in Cecil.
Trees and wires were blown down along Bausman Street.
Multiple trees were blown down in the area of Export.
Multiple trees and power lines were blown down in town.
A tree was reported to be downed near the intersection of Homer Lane and Colt Road.
Trees were reported to be blown down on Old Mercer Road.
In Riverside Park, trees were blown down.
Trees and power lines were reported to be blown down.
A tree and wires were blown down on Old Williamson Road near the tractor supply company. The tree was also reported to be on fire.
Several trees and wires were reported to be blown down just west of Grove City.
A few trees were reported to be blown down near Utica.
A couple trees were blown down near Route 38.
A tree was reported to be blown down on Hooker Road.
On East Beaver Street, trees were reported to be blown down.
A few trees were reported to be down.
On St. Patrick's Road, trees were reported to be blown down.
A tree was reportedly downed on Bunker Hill Road.
A tree was blown down on Wood Street.
A tree was blown down on Washington Road.
Route 28 was closed in the area of 217 Brookville Street due to live power lines being downed on to the road.
A few trees were downed near US Route 62.
Trees were reported down around the town of Tionesta.
Trees were reported to be downed along Route 28.
A number of trees were reported to be blown down in the northeastern portion of Indiana County.
On State Route 66, trees were blown down.
Trees were blown down on Route 36.
Thunderstorm wind threw bricks on to a roof, blew a hot tub cover through a sliding glass door, and knocked down numerous trees along Stiffler Road.
Trees were downed on Route 56 between Brush Valley and Armagh.
A tree was downed on Centerville Lane.
Numerous trees were blown down along Rhine Road.
Along Route 259, numerous trees were blown down.
A member of the public reported that trees were snapped on their property.
A tree fell through a mobile home along Shaffer Road.
Many trees were reported to be down in Brush Valley.
A tree was downed at Exit 46B of I-70.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2021Every state in 2021This day in weather historyWarnings in Pennsylvania, July 2021
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: 972952, 972953, 972954, 972955, 972956, 972957, 972958, 972959, 972960, 972961, 972962, 972963, 972964, 972965, 972966, 972967, 972968, 972969, 972970, 972971, 972972, 972974, 972976, 972977, 972978, 972979, 972981, 972982, 972983, 972985, 972986, 972987, 972988, 972989, 972990, 972991, 972992, 972993, 972994, 972995, and more.