Widespread severe thunderstorms formed during the afternoon and evening within an environment of moderate CAPE and moderate shear. A shortwave moved across the Ohio Valley giving support for multiple rounds of convection, primarily in the form of multicell clusters and linear segments.
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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 CTP wrote it up.
Widespread severe thunderstorms formed during the afternoon and evening within an environment of moderate CAPE and moderate shear. A shortwave moved across the Ohio Valley giving support for multiple rounds of convection, primarily in the form of multicell clusters and linear segments. Although damaging winds were the main impact, a few storms also created large hail. Flash flooding was reported from slow moving thunderstorms in Lycoming and Tioga Counties.
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 State College, PA wrote its last area forecast discussion before the first event at Jul 13, 2:33 PM EST, 1 hour 39 minutes earlier.
Area Forecast Discussion National Weather Service State College PA 333 PM EDT Tue Jul 13 2021 .SYNOPSIS... An upper level ridge will remain located off of the east coast for the rest of this week. Weakening shortwaves will push into Pennsylvania from the west late today and again on Wednesday. Afterward, high pressure is likely to build into the state late in the week. A slow moving cold front will likely push south through the region next weekend. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... Collaborated with BGM and WPC to issue a Flash Flood Watch through 04Z Wed across several of our NE counties where 1 hour FFG values are 1 inch or less. Shortly afterward, we were blanketed by Severe TSRA Watch #375. Heating of the very moist, unstable air mass has fueled a gradual increase of deepening convection, which was initially focused primarily along the elevated heat source along the spine of the Appalachians and along a boundary of strong differential heating at the edge of the stratus deck across our far East/SE zones. Increasing large scale forcing ahead of a shortwave approaching from the Ohio Valley should lead to increasing coverage late in the day and into the evening hours. Latest HREF supports the highest POPs in vicinity of a weak and shallow warm/quasi-stnry front (with an easterly flow and marine layer to its east) where pwats around 2 inches are progged. This front is also marked by a strong differential heating boundary with widespread stratus to its east through Poconos and Lehigh Valley. The high- pwat air, combined with moderate to high instability, should result in locally heavy downpours and the potential of localized flooding. The wettest members of the 00Z HREF indicate the potential of 2-3 inches in a few spots of the central mountains and Middle Susq Valley. Increasing winds aloft ahead of approaching shortwave will lead to respectable deep layer shear late in the day and evening, supporting a few supercells and even the chance of a tornado, where low level shear is enhanced near warm front over the Susq Valley. The highest HREF UH and greatest mesocyclone potential lie across the Middle Susq Valley. 850mb temps near 18C should translate to high temps in the low 90s across the Lower Susq Valley today. Further north and west, early afternoon convection is likely to hold readings in the 80s. Heat indices may touch 100F in a few spots of the Lower Susq Valley, but feel widespread 100+ readings are unlikely, so no heat advisory planned at this time. Evening convection should diminish in coverage/intensity late this evening, as boundary layer cools. Focus for lingering late night showers should be over the northwest part of the state, closest to weakening shortwave lifting through the eastern Grt Lks. Otherwise, expect light wind, partly cloudy skies and wet ground should promote patchy late night fog. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... A second shortwave is progged to lift across central Pa during peak heating Wednesday, supporting another round of PM convection. In general, the mid level wind fields and deep layer shear look fairly weak. However, moderate cape and slightly more impressive kinematic profiles over the Susq Valley could support isolated damaging wind gusts in that part of the state during the afternoon. Ensemble 850/2m temp plumes indicate Wednesday will be several degrees cooler than today with highs ranging from the upper 70s to upper 80s from northwest to southeast. Clearing skies and light wind associated with arrival of surface ridge should once again promote areas of valley fog Wednesday night. Ridging at the surface and aloft should result in fair and slightly less humid weather for most of the region Thursday. However, can't rule out an isolated PM tstorm over the northwest in association with falling heights and low level moisture return ahead of upstream trough over the Grt Lks. Mostly sunny skies and ensemble mean 850mb temps near 17C should support highs ranging from the low 80s to low 90s from northwest to southeast. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Thursday is the only day this week that will see a break in the active trend. Thursday will be mainly dry and sunny, only the small chance for a stray shower over the northwest. The upper- level trough is very slow to move out of the region, and more chances for afternoon and evening showers and thunderstorms return for Friday and the weekend. Models are producing a slow- moving cold front that will move NW to SE over the region Friday through Sunday. Warm, moist air will continue to be plentiful into the weekend. Flooding will still remain a concern for areas that have received heavy rainfall from previous storms as the ground is already saturated. We may see some relief from the active weather early next week (Tuesday at this point) as drier air moves in from the north and surface high pressure builds in. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... Low stratus with IFR to LIFR will linger for the next few hours northeast of a KSEG to KMDT and KMUI line, which resides on the cool side of a shallow stationary/warm frontal boundary with a light eastern flow of marine air off the Western Atlantic. Conditions will gradually improve to mainly MVFR there for the late afternoon while generally VFR persists elsewhere across much of Central PA. Another round or two of SHRA/TSRA will take place this afternoon and evening. Have included VCTS mention for all sites given the high likelihood of storms this afternoon/early evening. Outlook... Wed...A.M. low cigs/vis. Locally heavy showers and t-storms with restrictions likely during the afternoon. Thu-Sat...Isolated to scattered P.M. showers/t-storms. && .CTP WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch until midnight EDT tonight for PAZ037-041- 042-046-049>053. && SYNOPSIS...Lambert NEAR TERM...Lambert SHORT TERM...Lambert/Fitzgerald LONG TERM...Gutierrez AVIATION...Guseman/Lambert
Hazardous Weather Outlook National Weather Service State College PA 200 PM EDT Tue Jul 13 2021 PAZ037-041-042-046-049>053-141800- Tioga-Northern Lycoming-Sullivan-Southern Lycoming-Union-Snyder- Montour-Northumberland-Columbia- 200 PM EDT Tue Jul 13 2021 ...FLASH FLOOD WATCH IN EFFECT UNTIL MIDNIGHT EDT TONIGHT... ...SEVERE THUNDERSTORM WATCH 375 IN EFFECT UNTIL 11 PM EDT THIS EVENING... This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...This afternoon and tonight. Please listen to NOAA Weather Radio or go to weather.gov/StateCollege on the internet for more information about the following hazards. Flash Flood Watch. Severe Thunderstorm Watch. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Isolated strong to severe thunderstorms with gusty winds are possible Wednesday afternoon. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather. PAZ004>006-010>012-017>019-024>028-033>036-045-056>059-063>066- 141800- Warren-McKean-Potter-Elk-Cameron-Northern Clinton-Clearfield- Northern Centre-Southern Centre-Cambria-Blair-Huntingdon-Mifflin- Juniata-Somerset-Bedford-Fulton-Franklin-Southern Clinton-Perry- Dauphin-Schuylkill-Lebanon-Cumberland-Adams-York-Lancaster- 200 PM EDT Tue Jul 13 2021 ...SEVERE THUNDERSTORM WATCH 375 IN EFFECT UNTIL 11 PM EDT THIS EVENING... This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...This afternoon and tonight. Please listen to NOAA Weather Radio or go to weather.gov/StateCollege on the internet for more information about the following hazards. Severe Thunderstorm Watch. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Isolated strong to severe thunderstorms with gusty winds are possible Wednesday afternoon. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather. Lambert
Special Weather Statement National Weather Service State College PA 418 PM EDT Tue Jul 13 2021 PAZ033-132100- Somerset PA- 418 PM EDT Tue Jul 13 2021 ...A STRONG THUNDERSTORM WILL AFFECT PARTS OF SOMERSET COUNTY UNTIL 500 PM EDT... At 418 PM EDT, Doppler radar indicated a strong thunderstorm near Mount Davis, moving northeast at 15 mph. Wind gusts of 50 to 55 mph are possible. Locations impacted include... Somerset, Ursina, New Centerville, Mount Davis, Rockwood, Addison, Casselman and Seven Springs. PRECAUTIONARY/PREPAREDNESS ACTIONS... Torrential rainfall is also occurring with this storm, and may lead to localized flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 4001 7929 4000 7905 3972 7915 3972 7937 TIME...MOT...LOC 2018Z 216DEG 14KT 3983 7923 Travis
The Pittsburgh radar (KPBZ), 131 km away, was scanning. The volume nearest the first event began at 21:10 UTC.
23 thunderstorm wind, 2 hail, 2 flash flood, 1 lightning. Local standard time, as filed.
A severe thunderstorm with winds estimated near 60 mph brought down multiple trees.
A severe thunderstorm with winds estimated near 60 mph brought down multiple trees across PA-958.
A severe thunderstorm with winds estimated near 60 mph brought down multiple trees and wires along Route 62.
A severe thunderstorm with winds estimated near 60 mph brought down multiple trees across Route 6.
A severe thunderstorm with winds estimated near 60 mph brought down multiple trees in the area and snapped a power pole in half.
A severe thunderstorm with winds estimated near 60 mph brought down multiple trees and wires.
A severe thunderstorm with winds estimated near 60 mph brought down a large tree on top of a garage.
A severe thunderstorm with winds estimated near 60 mph brought down multiple trees across the road near Clearfield.
A severe thunderstorm with winds estimated near 60 mph brought down multiple trees and wires along route 6 east of Smethport.
A severe thunderstorm with winds estimated near 60mph brought down multiple trees in Wharton.
A severe thunderstorm with winds estimated near 60 mph snapped and uprooted multiple trees at the Riggles Gap Sportsmen Club.
A severe thunderstorm with winds estimated near 60 mph brought down 4 trees across Route 46.
A severe thunderstorm with winds estimated near 60 mph brought down multiple trees and wires on Airport Rd.
A severe thunderstorm with winds estimated near 60 mph brought down multiple trees in Austin.
A severe thunderstorm with winds estimated near 60 mph brought down multiple trees (broken or uprooted) along Dry Hollow Rd.
A severe thunderstorm with winds estimated near 60 mph brought down multiple trees and wires on Anaconda Dr.
A severe thunderstorm with winds estimated near 60 mph brought down multiple trees between Kettle Creek and South Renovo.
A thunderstorm produced a lightning strike that caused a house fire in the 200 block of Brothers Court in Patton Township.
A severe thunderstorm brought hail estimated in excess of one inch to the State College area.
A severe thunderstorm with winds estimated near 60 mph brought down multiple trees in Slate Run.
A severe thunderstorm with winds estimated near 60 mph brought down multiple trees in Richmond Township.
Flash flooding with water across the roadway on State Route 287 in Delmar Township.
A severe thunderstorm with winds estimated near 60 mph brought down multiple trees on wires.
A severe thunderstorm with winds estimated near 60 mph brought down trees on wires.
A severe thunderstorm brought hail estimated at 1.5 inches in diameter to Montgomery.
A severe thunderstorm with winds estimated near 60 mph brought down multiple trees in Forks Township.
Flash flooding brought multiple road closures along Muncy Creek in Muncy Township.
A severe thunderstorm with winds estimated near 60 mph brought down multiple trees in Gregg and White Deer Township.
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: 960697, 960698, 960699, 960701, 961644, 961648, 961646, 961631, 961649, 961626, 961638, 961635, 961652, 964691, 961657, 961670, 964693, 978197, 961668, 964686, 964687, 971587, 964689, 964690, 964688, 964692, 971588, 964694.