F1 tornado, Hammond to Erose, Kentucky, May 31, 2004

1. F040 to 72 mph

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. F173 to 112 mphthis tornado

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. 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.

4. 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.

5. F4207 to 260 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. 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.

7. 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.

Rating

F1

Date

May 31, 2004

Touchdown

2:15 AM EDT (06:15 UTC)

Path length

0.2 miles (0.3 km)

Path width

63 yards (58 m)

Deaths

0

Injuries

0

Property damage

$30,000

County

Knox County

Touchdown point

36.930, -83.620

Lift-off point

36.930, -83.620

Record number

1244

On the afternoon of May 30th, a warm front was draped across eastern Kentucky. With extremely moist and unstable air, this boundary helped spark the beginning of a most unusual event for eastern Kentucky, and for that matter, for the country. Countless supercell thunderstorms developed along this boundary for hours on end, causing widespread tree damage and damage to structures. Flash flooding was also occurring with these storms which contained torrential rain. Unfortunately for eastern Kentucky, this was not the end to the severe weather or the flooding. Later in the night, mostly in the early hours of May 31st, a potent cold front burst through, bringing destruction to most if not all eastern Kentucky counties. Also, so much rain had fallen from the previous afternoon and evening, coupled with more heavy rain during the morning of May 31st, that widespread aerial flooding occurred. For some counties, as was the case for Estill and Powell Counties, the aerial flooding lasted for days. The cost of these storms totaled easily in the millions.

A tornado, 210 feet wide, briefly touched down just south of Hammond. It lifted, and touched down again near Hammond. Numerous trees were down and two trailers, two homes, and on garage were damaged.

A tornado touched down near Erose along Highway 718. The tornado was on the ground for 1, 338 feet. Numerous trees were blown down and three homes were damaged.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

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.

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 Storm Prediction Center had this point in a General Thunderstorms Risk. The outlook in force was issued at 05:47 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 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.

London-Corbin Airport (LOZ), 44 km from the path, in the two hours either side.

From the Iowa Environmental Mesonet's archive of airport observations.

The Jackson,KY radar (KJKL), 78 km away, was scanning. The volume nearest the touchdown began at 06:15 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.

Local storm reports within 60 km of the path, in the three hours either side.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

The live radar over the trackEvery 2004 tornado in KentuckyEvery tornado in Kentucky since 1950Warnings in force in Kentucky nowThe forecast where you are

12 more were confirmed in the United States that day.

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.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.