EF0 tornado, Woodruff, Kansas, April 27, 2012

1. EF065 to 85 mphthis tornado

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

2. EF186 to 110 mph

   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

EF0

Date

April 27, 2012

Touchdown

4:43 PM CDT (21:43 UTC)

Lifted

4:52 PM CDT (21:52 UTC)

On the ground

9 minutes

Path length

4.4 miles (7.1 km)

Path width

40 yards (37 m)

Deaths

0

Injuries

0

County

Phillips County

Touchdown point

39.955, -99.298

Lift-off point

39.972, -99.218

Record number

1204271543-01

2 damage points were recorded along this path by NWS GID, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 70 mph.

• Tornado on Ground from 4:43 pm to 4:52 pm. No damage reported.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

Multiple rounds of strong to severe thunderstorms lifted across this six-county area on this Friday. Although the afternoon hours primarily featured several reports of hail up to half dollar size in the Osborne and Mitchell County area, a brief EF0 tornado tracked across far northern Phillips County, with no damage reported.||Breaking down the timing of this event, strong thunderstorms lifted across parts of the area during the morning hours, but remained below severe limits. Then between noon and 2 PM CDT, a narrow arc of storms gradually intensified, especially over Osborne County. Between 2-4 PM CDT, this line of storms swept across Mitchell and Jewell Counties before quickly departing to the east. Although it initially appeared the severe threat had dwindled by this point, additional small, seemingly weak thunderstorms developed directly under the center of the mid level cold pocket between 4-5 PM CDT, with one of these spawning the brief Phillips County tornado as captured on video by a storm chaser. ||Aloft, this event was driven by a well-defined, negatively tilted mid level shortwave that passed directly overhead as it tracked from near the Kansas/Colorado border in the morning, to eastern Nebraska by late evening. Although this mid level wave did not necessarily feature a true closed circulation at 500 millibars, the Phillips County tornado nonetheless possessed the characteristics of most cold-core tornado events. This included a parent low-topped storm with rotational signatures difficult to detect via radar. At the surface, a strong low pressure center deepened to around 996 millibars over the heart of North Central Kansas by mid-afternoon, with a well-defined warm front extending southeast into southeast Kansas, and a sharp dryline surging into central Kansas from the west. Mesoscale severe weather parameters during the early to mid-afternoon time frame featured a narrow tongue of surface based CAPE between 500-1500 J/Kg, in the presence of around 40 knots of deep layer vertical wind shear.

This tornado touched down approximately 7 miles east of Woodruff and lifted approximately 10 miles east of Woodruff. No damage was reported with this tornado.

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.

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 19:59 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.

The Grand Island radar (KUEX), 80 km away, was scanning. The volume nearest the touchdown began at 21:42 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.

The live radar over the trackEvery 2012 tornado in KansasEvery tornado in Kansas since 1950Warnings in force in Kansas nowThe forecast where you are

7 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.