Alert archive / Pennsylvania / Tornado Watches in 2021
Tornado Watch 510
The Storm Prediction Center issued this tornado watch at Sep 22, 2021, 2:23 PM EDT for 13 counties in Ohio; 17 counties in Pennsylvania; 7 counties in West Virginia. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 22, 2021, 2:23 PM EDT (18:23 UTC)
- Expired
- Sep 22, 2021, 8:04 PM EDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 37 counties
Ashtabula County, OH, Belmont County, OH, Carroll County, OH, Columbiana County, OH, Geauga County, OH, Harrison County, OH, Jefferson County, OH, Lake County, OH, Mahoning County, OH, Monroe County, OH, Portage County, OH, Stark County, OH, Trumbull County, OH, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Butler County, PA, Clarion County, PA, Crawford County, PA, Erie County, PA, Fayette County, PA, Forest County, PA, Greene County, PA, Indiana County, PA, Jefferson County, PA, Lawrence County, PA, Mercer County, PA, Venango County, PA, Washington County, PA, Westmoreland County, PA, Brooke County, WV, Hancock County, WV, Marion County, WV, Marshall County, WV, Monongalia County, WV, Ohio County, WV, Wetzel County, WV
The radar
The Pittsburgh radar (KPBZ), 64 km from the middle of the area, began a volume at 18:24 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 5%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 50%
Warnings issued inside it
11 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 22, 2:48 PM EDT | Severe Thunderstorm Warning | PBZ | Monroe | 27 min |
| Sep 22, 2:59 PM EDT | Severe Thunderstorm Warning | CLE | Mahoning, Portage, Stark, Trumbull | 61 min |
| Sep 22, 3:04 PM EDT | Severe Thunderstorm Warning | PBZ | Belmont, Carroll, Guernsey, Harrison, Noble, Tuscarawas | 26 min |
| Sep 22, 3:10 PM EDT | Severe Thunderstorm Warning | CLE | Ashtabula, Geauga, Portage, Trumbull | 65 min |
| Sep 22, 3:12 PM EDT | Severe Thunderstorm Warning | PBZ | Belmont, Monroe | 33 min |
| Sep 22, 3:28 PM EDT | Severe Thunderstorm Warning | PBZ | Belmont, Guernsey, Harrison, Jefferson | 32 min |
| Sep 22, 3:43 PM EDT | Severe Thunderstorm Warning | PBZ | Belmont, Harrison, Jefferson | 16 min |
| Sep 22, 3:58 PM EDT | Severe Thunderstorm Warning | CLE | Ashtabula, Trumbull | 47 min |
| Sep 22, 4:17 PM EDT | Tornado Warning | CLE | Ashtabula | 28 min |
| Sep 22, 5:43 PM EDT | Tornado Warning | PBZ | Armstrong, Butler | 18 min |
| Sep 22, 6:04 PM EDT | Tornado Warning | PBZ | Butler, Venango | 12 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Pittsburgh, PA (KPIT), launched 12:00Z, 6.4 hours before the alert went out and 79 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 155 J/kg
- Mixed-layer CIN
- -120 J/kg
- Mixed-layer LCL
- 634 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km storm-relative helicity
- 32 m²/s²
- 0-3 km storm-relative helicity
- 88 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.5
The text
As transmitted.
667 WWUS20 KWNS 221818 SEL0 SPC WW 221818 OHZ000-PAZ000-WVZ000-LEZ000-230200- URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 510 NWS Storm Prediction Center Norman OK 220 PM EDT Wed Sep 22 2021 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Eastern Ohio Western Pennsylvania Northern West Virginia Lake Erie * Effective this Wednesday afternoon and evening from 220 PM until 1000 PM EDT. * Primary threats include... A couple tornadoes possible Scattered damaging wind gusts to 70 mph possible SUMMARY...Thunderstorms will intensify this afternoon along a cold front over eastern Ohio, and track northeastward across the watch area. Locally damaging winds are the main threat with these storms, although tornadoes are possible in the most intense cells. The tornado watch area is approximately along and 55 statute miles east and west of a line from 20 miles west northwest of Erie PA to 30 miles west southwest of Morgantown WV. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU0). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. && AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 21035. ...Hart
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 22, 1:08 PM EDT | Mesoscale Discussion | SPC | Ashtabula, Belmont, Carroll, Columbiana, Geauga, Guernsey and 11 more | 3 hr |
| Sep 22, 4:08 PM EDT | Mesoscale Discussion | SPC | Ashtabula, Carroll, Columbiana, Jefferson, Mahoning, Trumbull | 97 min |
| Sep 22, 6:13 PM EDT | Mesoscale Discussion | SPC | Armstrong, Butler, Clarion, Crawford, Erie, Forest and 5 more | 92 min |
| Sep 22, 2:44 PM EDT | Mesoscale Discussion | SPC | Monroe | 3 hr |
Nearby
Tornado Watches in Pennsylvania, 2021Tornado Watches in Ohio, 2021Tornado Watches in West Virginia, 2021Every tornado watch in 2021
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.