Tornadoes · United States · Pennsylvania · 2009
EF1 tornado, Force to Tyler, Pennsylvania, August 9, 2009
From Force to Tyler, this EF1 tornado ran 1.5 miles across Elk and Clearfield counties on August 9, 2009, touching down at 4:58 PM EDT and reaching 150 yards wide. It killed nobody, and did $10,000 of property damage.
The rating scale
Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.
EF065 to 85 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mphthis tornado
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
EF2111 to 135 mph
Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.
EF3136 to 165 mph
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
EF5over 200 mph
Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.
Unrated
The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.
The record
- Rating
- EF1
- Date
- August 9, 2009
- Touchdown
- 4:58 PM EDT (20:58 UTC)
- Lifted
- 5:02 PM EDT (21:02 UTC)
- On the ground
- 4 minutes
- Path length
- 1.5 miles (2.4 km)
- Path width
- 150 yards (137 m)
- Deaths
- 0
- Injuries
- 0
- Property damage
- $10,000
- Counties
- Elk and Clearfield counties
- Touchdown point
- 41.251, -78.532
- Lift-off point
- 41.225, -78.523
- Record number
- 0908091458-01
What the Weather Service recorded
The National Weather Service in State College confirmed EF1 tornado damage near Tyler in northern Clearfield County.
The National Weather Service in State College confirmed EF1 tornado damage near Tyler in northern Clearfield County, with maximum wind speeds between 95 and 100 mph. The tornado touched down just north of Scattertown in Elk County and moved south crossing into Clearfield County, before lifting about one-half mile south of Tyler. One home in Tyler sustained minor damage with about two dozen trees knocked down in the tornado path.
The National Weather Service in State College confirmed EF1 tornado damage near Tyler in northern Clearfield County, with maximum wind speeds between 95 and 100 mph. The tornado touched down just north of Scattertown in Elk County and moved south crossing into Clearfield County, before lifting about one-half mile south of Tyler. One home in Tyler sustained minor damage with about two dozen trees knocked down in the tornado path.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
48 minutes of warning. NWS CTP issued a tornado warning for this county at 20:10 UTC, 48 minutes before the tornado touched down, in force until 21:00 UTC.
The county was under a severe thunderstorm watch, issued at 16:00 UTC and running to 22:22 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 16:00 UTC | 22:22 UTC | Severe Thunderstorm Watch | CTP |
| 19:28 UTC | 20:30 UTC | Severe Thunderstorm Warning | CTP |
| 20:10 UTC | 21:00 UTC | Tornado Warning | CTP |
| 20:56 UTC | 21:30 UTC | Tornado Warning | CTP |
| 02:45 UTC | 07:00 UTC | Severe Thunderstorm Watch | CTP |
Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.
The forecast that day
The Storm Prediction Center had this point in a Slight Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 20:01 UTC.
SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.
The air that afternoon
The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.
Pittsburgh, PA (KPIT), 12:00Z
9.0 hours before the tornado, 161 km from the path. August 9, 2009.
- Mixed-layer CAPE
- 1344 J/kg
- Mixed-layer CIN
- -14 J/kg
- Surface CAPE
- 625 J/kg
- Mixed-layer LCL
- 591 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 201 m²/s²
- 0-3 km storm-relative helicity
- 199 m²/s²
- Significant tornado parameter
- 1.0
- Supercell composite
- 5.7
- 0-3 km lapse rate
- 5.1 K/km
Pittsburgh, PA (KPIT), 00:00Z
3.0 hours after it, 161 km from the path. August 10, 2009.
- Mixed-layer CAPE
- 70 J/kg
- Mixed-layer CIN
- -145 J/kg
- Surface CAPE
- 705 J/kg
- Mixed-layer LCL
- 1781 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km bulk shear
- 17 kt
- 0-1 km storm-relative helicity
- 61 m²/s²
- 0-3 km storm-relative helicity
- 129 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
- 0-3 km lapse rate
- 6.6 K/km
The surface observations
Clearfield-Lawrence Apt(Was N97) (FIG), 23 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 19:34 UTC | 82.4 | 71.6 | 260° 5 kt | 1019.3 | -TSRA | |
| 19:41 UTC | 80.6 | 73.4 | 290° 6 kt | 1019 | -TSRA | |
| 19:49 UTC | 80.6 | 73.4 | 250° 6 kt | 1019 | HZ | |
| 19:54 UTC | 83 | 74 | 260° 7 kt | 1019 | HZ | |
| 20:50 UTC | 84.2 | 71.6 | 250° 4 kt | 1019 | TS HZ | |
| 20:54 UTC | 85 | 72 | 200° 6 kt | 1018.6 | TS HZ | |
| 21:54 UTC | 77 | 72 | 10° 8 kt | 17 | 1019.3 | TS HZ |
| 22:36 UTC | 78.8 | 71.6 | 270° 4 kt | 1017.9 | HZ | |
| 22:54 UTC | 77 | 69 | 350° 4 kt | 1017.6 |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The State College radar (KCCX), 56 km away, was scanning. The volume nearest the touchdown began at 20:57 UTC.
Open the radar archive at this moment, over the track
Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.
What was reported nearby
Local storm reports within 60 km of the path, in the three hours either side.
| Time (UTC) | Report | Where | County | Remark |
|---|---|---|---|---|
| 20:15 UTC | HAIL 1 | St. Marys | Elk, PA | |
| 20:25 UTC | TSTM WND DMG | 8 S St. Marys | Elk, PA | NUMEROUS LARGE TREES AND WIRES DOWN IN WEEDVILLE. |
| 21:25 UTC | TORNADO | 5 Ese Penfield | Clearfield, PA | TORNADO REPORTED ON THE GROUND IN PARKER STATE PARK ALONG TYLER ROAD. |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2009 tornado in PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are
The other tornadoes of August 9, 2009
1 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| August 9 | 2:05 PM EDT | EF1 | Allegany, NY | 7.8 | 25 | $200,000 |
What this means
Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.
Sources
NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.