Tornadoes · United States · Pennsylvania · 2009
EF0 tornado, White Deer, Pennsylvania, July 11, 2009
This EF0 tornado ran 1.0 miles across Union County on July 11, 2009, touching down at 5:40 PM EDT and reaching 50 yards wide. It killed nobody, and did $5,000 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 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
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
- EF0
- Date
- July 11, 2009
- Touchdown
- 5:40 PM EDT (21:40 UTC)
- Lifted
- 5:42 PM EDT (21:42 UTC)
- On the ground
- 2 minutes
- Path length
- 1.0 miles (1.6 km)
- Path width
- 50 yards (46 m)
- Deaths
- 0
- Injuries
- 0
- Property damage
- $5,000
- County
- Union County
- Touchdown point
- 41.080, -76.947
- Lift-off point
- 41.071, -76.928
- Record number
- 0907111540-01
What the Weather Service recorded
The National Weather Service in State College confirmed an EF0 tornado near White Deer Furnace in Union County.
An EF0 tornado, with maximum wind speeds estimated around 75 mph, touched down on the north side of Interstate 80 and moved southeast for approximately one mile. The tornado crossed Interstate 80 before lifting near White Deer Furnace. Damage was minimal with about ten trees and several large branches blown down or uprooted. Eye witnesses, including a Pennsylvania State Trooper, reported broad rotation within the storm and a funnel reaching the ground.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
12 minutes of warning. NWS CTP issued a tornado warning for this county at 21:28 UTC, 12 minutes before the tornado touched down, in force until 22:00 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 20:58 UTC | 22:00 UTC | Severe Thunderstorm Warning | CTP |
| 21:28 UTC | 22:00 UTC | Tornado Warning | CTP |
| 23:19 UTC | 00:30 UTC | Severe Thunderstorm Warning | CTP |
| 00:28 UTC | 01:30 UTC | Severe Thunderstorm Warning | CTP |
| 01:54 UTC | 04:45 UTC | Flood Advisory | CTP |
| 02:33 UTC | 06:54 UTC | Flash Flood Warning | 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 surface observations
Williamsport (IPT), 19 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 19:54 UTC | 77 | 65 | 140° 4 kt | 1015.6 | ||
| 20:54 UTC | 77 | 66 | 4 kt | 1014.6 | ||
| 21:05 UTC | 77 | 66.2 | 3 kt | 1014.6 | TS | |
| 21:14 UTC | 75.2 | 66.2 | 220° 5 kt | 1014.9 | +TSRA | |
| 21:20 UTC | 73.4 | 69.8 | 240° 5 kt | 1014.6 | +TSRA | |
| 21:28 UTC | 73.4 | 69.8 | 5 kt | 1014.9 | -TSRA BR | |
| 21:32 UTC | 73.4 | 69.8 | 4 kt | 1014.9 | -TSRA | |
| 21:54 UTC | 74 | 66 | 4 kt | 1014.2 | TS | |
| 22:21 UTC | 75.2 | 66.2 | 330° 3 kt | 1013.9 | ||
| 22:54 UTC | 75 | 67 | 80° 3 kt | 1013.5 | ||
| 23:39 UTC | 71.6 | 66.2 | 110° 6 kt | 1012.2 |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The State College radar (KCCX), 91 km away, was scanning. The volume nearest the touchdown began at 21:37 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 |
|---|---|---|---|---|
| 21:10 UTC | TSTM WND DMG | 2 Sw Williamsport | Lycoming, PA | TREES AND WIRES DOWN IN SUSQUEHANNA STATE PARK. |
| 21:45 UTC | TORNADO | Watsontown | Northumberland, PA | TORNADO OBSERVED ON THE GROUND. |
| 21:50 UTC | TORNADO | 2 N Milton | Northumberland, PA | TORNADO OBSERVED BY STATE TROOPER ON I-80. |
| 21:51 UTC | HAIL 0.75 | Turbotville | Northumberland, PA | |
| 22:32 UTC | TSTM WND DMG | 3 W Bloomsburg | Columbia, PA | TREES REPORTED DOWN 3W OF BLOOMSBURG. ESTIMATED 60 MPH WIND GUST. |
| 22:32 UTC | TSTM WND DMG | Bloomsburg | Columbia, PA | TREES AND WIRES REPORTED DOWN IN BLOOMSBURG. |
| 23:45 UTC | TSTM WND DMG | 3 N Lock Haven | Clinton, PA | TREES REPORTED DOWN ALONG RT 664 HALF A MILE SOUTH OF SWISSDALE. |
| 23:59 UTC | HAIL 1.25 | Montoursville | Lycoming, PA |
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 July 11, 2009
4 more were confirmed in the United States that day.
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.