Tornadoes · United States · Pennsylvania · 2004
F1 tornado, Dover, Pennsylvania, July 14, 2004
This F1 tornado ran 5.0 miles across York County on July 14, 2004, touching down at 2:39 PM EDT and reaching 100 yards wide. It killed nobody, and did $100,000 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
- July 14, 2004
- Touchdown
- 2:39 PM EDT (18:39 UTC)
- Path length
- 5.0 miles (8.0 km)
- Path width
- 100 yards (91 m)
- Deaths
- 0
- Injuries
- 0
- Property damage
- $100,000
- County
- York County
- Touchdown point
- 40.170, -76.850
- Lift-off point
- 40.170, -76.850
- Record number
- 342
What the Weather Service recorded
Thunderstorms spawned a weak F1 tornado during the afternoon of Wednesday July 14 in northern York County. The tornado first touched down at the intersection of Route 83 and Fishing Creek Road in Frogtown, about 11.5 miles north of Dover. The tornado traveled east, damaging two buildings. Wind blown debris from the tornado knocked out dozens of car windows. The tornado path was one half mile long, and 100 yards wide. Winds were estimated between 73 and 112 mph, making this an F1 on the Fujita scale.The tornado was embedded in a larger area of downburst damage. Dozens of trees were blown down and a barn roof was blown off in this three mile long swath of downburst damage. There were no injuries or deaths.
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. One was issued for the county at another hour that day.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 18:43 UTC | 19:45 UTC | Severe Thunderstorm Warning | CTP |
| 19:19 UTC | 20:00 UTC | Tornado 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 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
6.7 hours before the tornado, 101 km from the path. July 14, 2004.
- Mixed-layer CAPE
- 3 J/kg
- Mixed-layer CIN
- -233 J/kg
- Surface CAPE
- 7 J/kg
- Mixed-layer LCL
- 719 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- 91 m²/s²
- 0-3 km storm-relative helicity
- 125 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 4.7 K/km
The surface observations
Harrisburg/Capital (CXY), 5 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 16:56 UTC | 74 | 72 | 70° 8 kt | 1002.7 | BR | |
| 17:35 UTC | 75.2 | 73.4 | 80° 8 kt | 1001.7 | BR | |
| 17:47 UTC | 75.2 | 73.4 | 90° 9 kt | 1001 | -RA BR | |
| 17:56 UTC | 76 | 75 | 70° 7 kt | 1001 | -RA BR | |
| 18:42 UTC | 73.4 | 71.6 | 320° 20 kt | 25 | 1002.4 | -RA BR |
| 18:46 UTC | 69.8 | 68 | 290° 10 kt | 25 | 1002.7 | +RA BR |
| 18:56 UTC | 68 | 64 | 4 kt | 20 | 1001.4 | +RA FG |
| 18:59 UTC | 68 | 64.4 | 3 kt | 1001 | +RA BR | |
| 19:02 UTC | 69.8 | 64.4 | 3 kt | 1001 | -RA BR | |
| 19:07 UTC | 69.8 | 64.4 | 4 kt | 1000.7 | -RA | |
| 19:17 UTC | 69.8 | 66.2 | 4 kt | 1000.3 | ||
| 19:56 UTC | 74 | 68 | 320° 4 kt | 999.7 |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The State College radar (KCCX), 129 km away, was scanning. The volume nearest the touchdown began at 18:39 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 |
|---|---|---|---|---|
| 18:30 UTC | TSTM WND DMG | Biglerville | Adams, PA | TREES AND POWER LINES DOWN |
| 18:35 UTC | TSTM WND GST 62 | Shiremanstown | Cumberland, PA | GUST TO 62 MILES PER HOUR WAS REPORTED |
| 18:52 UTC | TSTM WND DMG | Dauphin | Dauphin, PA | TREES AND LIMBS DOWN |
| 18:55 UTC | TSTM WND DMG | York | York, PA | TREES DOWN AT NEWBERRY TOWNSHIP |
| 19:00 UTC | TSTM WND DMG | Dauphin | Dauphin, PA | TREES DOWN |
| 19:15 UTC | TSTM WND DMG | 6 Se Palmyra | Lebanon, PA | MANY HOUSES DAMAGED EAST AND ALONG ROUTE 322 |
| 19:15 UTC | HAIL 0.75 | 4 N Dover | York, PA | PENNY SIZE HAIL REPORTED AT ROUTE 30 |
| 19:20 UTC | HAIL 0.25 | Manchester | York, PA | PEA SIZE HAIL REPORTED |
| 19:20 UTC | HAIL 0.88 | Manheim | Lancaster, PA | NICKEL SIZE HAIL REPORTED |
| 20:00 UTC | HAIL 0.88 | Elizabethtown | Lancaster, PA | MARBLE TO NICKEL SIZE HAIL AND 74 MPH WINDS REPORTED BETWEEN ELIZABETHTOWN AND BAINBRIDGE |
| 20:25 UTC | HAIL 1 | Lancaster | Lancaster, PA | QUARTER SIZE HAIL REPORTED |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2004 tornado in PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are
The other tornadoes of July 14, 2004
10 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| July 14 | 3:05 PM EDT | F3 | Lebanon, PA | 7.5 | 500 | $18 million | ||
| July 14 | 4:50 PM EDT | F1 | Saint Mary's, MD | 3.0 | 250 | $10,000 | ||
| July 14 | 4:20 PM CDT | F0 | Madison, AL | 1.0 | 50 | 1 | $10,000 | |
| July 14 | 6:14 PM EDT | F0 | Cherokee, GA | 0.2 | 50 | $1,000 | ||
| July 14 | 5:25 PM CDT | F0 | Colbert, AL | 0.2 | 60 | |||
| July 14 | 5:40 PM CDT | F0 | Colbert, AL | 0.3 | 128 | |||
| July 14 | 6:43 PM EDT | F0 | Cherokee, GA | 0.1 | 50 | $1,000 | ||
| July 14 | 8:19 PM MDT | F0 | Sheridan, MT | 0.1 | 10 | |||
| July 14 | 8:35 PM MDT | F0 | Sheridan, MT | 6.1 | 10 | |||
| July 14 | 8:40 PM MDT | F0 | Sheridan, MT | 0.1 | 10 |
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.