EF1 tornado, Kremlin, Oklahoma, April 26, 2009

1. EF065 to 85 mph

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

2. EF186 to 110 mphthis tornado

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

3. 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.

4. 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.

5. EF4166 to 200 mph

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

6. 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.

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

EF1

Date

April 26, 2009

Touchdown

1:39 AM CDT (06:39 UTC)

Lifted

1:50 AM CDT (06:50 UTC)

On the ground

11 minutes

Path length

1.5 miles (2.4 km)

Path width

500 yards (457 m)

Deaths

0

Injuries

0

County

Garfield County

Touchdown point

36.548, -97.867

Lift-off point

36.553, -97.844

Record number

0904260039-01

Thunderstorms developed ahead of a dry line, and then ahead of a cold front by late afternoon. Very large hail up to baseball size was reported at several locations. Later in the evening, the low-level jet developed, increasing wind shear and making the environment more conducive for tornadoes. Low-level rotation became more common with the thunderstorms, with a couple of storms over north central Oklahoma producing tornadoes. Damage was reported in the northern Enid and Hillsdale areas, but no significant injuries were reported. The storms moved northeast into Kansas after midnight.

A large tornado was observed by storm chasers from KWTV for over 10 minutes. Fortunately, this tornado mostly moved through open farmland with only isolated damage observed between 1 mile and 2 miles west of Kremlin. A barn was destroyed, power poles were damaged, and some roof damage to a house were observed between Kremlin and US-81.

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

59 minutes of warning. NWS OUN issued a tornado warning for this county at 05:40 UTC, 59 minutes before the tornado touched down, in force until 06:45 UTC.

The county was under a tornado watch, issued at 03:39 UTC and running to 07:39 UTC.

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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 06:01 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 Vance AFB radar (KVNX), 32 km away, was scanning. The volume nearest the touchdown began at 06:40 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 2009 tornado in OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

10 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.