Tornadoes · United States · Pennsylvania · 2006
F1 tornado, Landenberg, Pennsylvania, August 29, 2006
This F1 tornado ran 2.0 miles across Chester County on August 29, 2006, touching down at 3:40 PM EDT and reaching 150 yards wide. It killed nobody, and did $70,000 of property damage.
The rating scale
Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.
F040 to 72 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
F173 to 112 mphthis tornado
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
F2113 to 157 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.
F3158 to 206 mph
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
F4207 to 260 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
F5261 to 318 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
- F1
- Date
- August 29, 2006
- Touchdown
- 3:40 PM EDT (19:40 UTC)
- Path length
- 2.0 miles (3.2 km)
- Path width
- 150 yards (137 m)
- Deaths
- 0
- Injuries
- 0
- Property damage
- $70,000
- County
- Chester County
- Touchdown point
- 39.780, -75.770
- Lift-off point
- 39.800, -75.730
- Record number
- 853
What the Weather Service recorded
An F1 (Fujita Scale) tornado touched down in the Landenburg area of New Garden Township. The tornado initially touched down southwest of Pennsylvania State Route 41 near Cooper Road. It moved southeast parallel of the sate route and proceeded to do some of its worst damage on Penn Green Road. A trailer was pushed off its foundation. The tornado then tore the roof off a service building at Guizzetti Mushroom Farm and damaged the roof of three mushroom houses. One of the mushroom house doors were ripped away. The mushrooms were also damaged. The remains of the repair shop were found up to mile upwind. The tornado then crossed Starr Road, Newark Road and Egypt Run Road before it lifted. The tornado's path barely just passed bythe Kennett Middle School by several hundred yards. It also just barely missed a township building. Some of the worst tree damage was on Penn Green Road, Egypt Run Road and sections of Reynolds and Sunnydell Street. Egypt Run Road, Pennsylvania State Route 41 and Starr Road were closed because of downed trees. A shed rolled over and was destroyed on Belmont Circle. Egypt Run Road home was blown off one home. In all about six homes suffered minor damage on Starr, Egypt Run and Reynolds Roads. About 150 homes and businesses lost power. Power was restored By 11 p.m. EDT on the 30th. The tornado's path length was estimated at about 2.0 miles with the maximum path width of about 150 yards. The estimated maximum winds were about 100 mph.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.
The county was under a tornado watch, issued at 17:53 UTC and running to 00:00 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 10:00 UTC | 00:00 UTC | Flood Watch | PHI |
| 17:53 UTC | 00:00 UTC | Tornado Watch | PHI |
| 18:53 UTC | 19:45 UTC | Severe Thunderstorm Warning | PHI |
| 19:37 UTC | 20:45 UTC | Severe Thunderstorm Warning | PHI |
| 19:39 UTC | 22:30 UTC | Flash Flood Warning | PHI |
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 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 16:30 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.
Phillips Aaf/Abe, MD (KAPG), 12:00Z
7.7 hours before the tornado, 47 km from the path. August 29, 2006.
- Mixed-layer CAPE
- 21 J/kg
- Mixed-layer CIN
- -132 J/kg
- Surface CAPE
- 654 J/kg
- Mixed-layer LCL
- 934 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 98 m²/s²
- 0-3 km storm-relative helicity
- 185 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
- 0-3 km lapse rate
- 4.9 K/km
The radar
The Dover AFB radar (KDOX), 111 km away, was scanning. The volume nearest the touchdown began at 19:38 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 |
|---|---|---|---|---|
| 18:45 UTC | FLASH FLOOD | Shillington | Berks, PA | SIGNIFICANT STREET FLOODING REPORTED ON ROUTE 222 IN SHILLINGTON. |
| 18:45 UTC | HEAVY RAIN 3 | Shillington | Berks, PA | 3.00 INCHES OF RAIN WAS REPORTED IN JUST 50 MINUTES IN SHILLINGTON. |
| 19:10 UTC | TSTM WND DMG | 5 Sse Parkesburg | Chester, PA | WIRES REPORTED DOWN IN COCHRANVILLE. |
| 19:15 UTC | TSTM WND DMG | Pottsgrove | Montgomery, PA | WIRES REPORTED DOWN IN LOWER POTTSGROVE. |
| 19:47 UTC | TSTM WND DMG | Philadelphia | Philadelphia, PA | TREE KNOCKED DOWN IN SOUTH PHILADELPHIA. |
| 19:50 UTC | TSTM WND DMG | 5 E West Grove | Chester, PA | A ROOF WAS BLOWN OFF A COMMERCIAL BUILDING IN NEW GARDEN TOWNSHIP ON PENN GREEN ROAD. 2 FUNNEL CLOUDS SIGHTED IN THE LANDENBERG AREA WITH A POSSIBLE TORNADO TOUCHDOWN. |
| 19:50 UTC | TSTM WND DMG | 5 E West Grove | Chester, PA | A ROOF WAS REPORTEDLY BLOWN OFF A COMMERCIAL BUILDING IN NEW GARDEN TOWNSHIP ON PENN GREEN ROAD. |
| 19:50 UTC | TSTM WND DMG | 5 E West Grove | Chester, PA | PROBABLE TORNADO IN NEW GARDEN TOWNSHIP. EMERGENCY MANAGEMENT OFFICIALS REPORTED 1 COMMERCIAL BUILDING DESTROYED, 3 TO 4 OTHER COMMERCIAL BUILDINGS WITH MINOR TO MODERATE DAMAGE AND 2 HOMES WITH MINOR DAMAGE. ALSO, NUMER |
| 19:50 UTC | TORNADO 1 | 5 E West Grove | Chester, PA | PRELIMINARY NWS SURVEY CONFIRMS AN F1 TORNADO IN NEW GARDEN TOWNSHIP. THE TRACK WAS MOSTLY CONTINUOUS AT A LENGTH OF APPROXIMATELY 2 MILES AND A MAXIMUM WIDTH OF 150 YARDS. WINDS ARE ESTIMATED TO HAVE BEEN 100 MPH. EMERG |
| 19:50 UTC | TORNADO | 5 E West Grove | Chester, PA | PRELIMINARY NWS SURVEY CONFIRMS AN F1 TORNADO IN NEW GARDEN TOWNSHIP. THE TRACK WAS MOSTLY CONTINUOUS AT A LENGTH OF APPROXIMATELY 2 MILES AND A MAXIMUM WIDTH OF 150 YARDS. WINDS ARE ESTIMATED TO HAVE BEEN 100 MPH. EMERG |
| 20:00 UTC | TSTM WND DMG | Chester Heights | Delaware, PA | WIRES REPORTED DOWN IN CHESTER HEIGHTS. |
| 20:00 UTC | FLASH FLOOD | 2 Se Phoenixville | Chester, PA | HIGHWAY, STREET AND POOR DRAINAGE FLOODING REPORTED IN VALLEY FORGE AS A RESULT OF RAINFALL RATES OF 2 TO 3 INCHES PER HOUR. |
| 20:37 UTC | TSTM WND DMG | 5 Sw Phoenixville | Chester, PA | WIRES REPORTED DOWN IN CHARLESTOWN TOWNSHIP. |
| 21:00 UTC | FLASH FLOOD | Shillington | Berks, PA | FLASH FLOODING OF STREETS AND SMALL STREAMS AND CREEKS WERE REPORTED IN SHILLINGTON. |
| 21:55 UTC | TSTM WND GST 50 | Exton | Chester, PA | A 50 MPH THUNDERSTORM WIND GUST WAS REPORTED IN EXTON, WITH BRANCHES DOWN. |
| 22:00 UTC | HEAVY RAIN 2.04 | Royersford | Montgomery, PA | 2.04 INCHES OF RAIN WAS MEASURED IN ROYERSFORD. THERE WERE REPORTS OF SOME BASEMENT FLOODING IN PARTS OF WESTERN MONTGOMERY COUNTY. |
| 22:15 UTC | FLOOD | Phoenixville | Chester, PA | MINOR FLOODING REPORTED ALONG THE FRENCH AND PICKERING CREEKS NEAR PHOENIXVILLE. |
| 22:25 UTC | HEAVY RAIN 2.07 | Exton | Chester, PA | 2.07 INCHES OF RAIN WAS MEASURED IN EXTON. |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2006 tornado in PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are
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.