Tornadoes · United States · Colorado · 2018
EF0 tornado, Arickaree to Cope, Colorado, May 28, 2018
From Arickaree to Cope, this EF0 tornado ran 0.1 miles across Washington County on May 28, 2018, touching down at 5:11 PM MDT and reaching 50 yards wide. It killed nobody.
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
- May 28, 2018
- Touchdown
- 5:11 PM MDT (23:11 UTC)
- Lifted
- 5:27 PM MDT (23:27 UTC)
- On the ground
- 16 minutes
- Path length
- 0.1 miles (0.2 km)
- Path width
- 50 yards (46 m)
- Deaths
- 0
- Injuries
- 0
- County
- Washington County
- Touchdown point
- 39.650, -102.920
- Lift-off point
- 39.650, -102.920
- Record number
- 1805281711-01
What the Weather Service recorded
Severe thunderstorms formed the afternoon of Memorial Day. Fourteen tornadoes were observed by spotters and chasers in the afternoon. A rare sighting of a tornado was reported from Jackson County. Some of the strongest storms formed across northeast Colorado, along a surface convergence boundary. The boundary extended from Kit Carson County north into Washington County, and then through Morgan and Weld counties. Intense convection that developed right on top of the boundary generated several tornadoes, with a few occurring simultaneously, especially across extreme southeast Washington County. Most of the tornadoes touched down in open fields and produced just minor crop damage. The heaviest damage occurred in Cope, in southeast Washington County, from an EF-1 tornado. It caused extensive damage to a carport and garage on the southeast side of town, and downed some trees. The storms also produced hail up to the size of tennis balls in Washington County. Further west, across the foothills west of Denver and across metro Denver, instability was weaker and marginally severe hail occurred, including accumulating hail across the south metro Denver.
A tornado touched down in an open field and likely produced some crop damage. Another tornado touched down in close proximity to this one.
A tornado touched down in a corn field. Some crop damage was likely.
One of three landspouts that formed in an open field in close proximity to one another. |No damage was observed.
This is the second of three tornadoes that touched down simultaneously in close proximity to one another. No damage was reported and the storm eventually crossed into Kit Carson County.
The last in a series of three landspouts touched down in close proximity to one another. |It touched down in an open corn field and likely produced some crop damage.
This was the third of three tornadoes that was visible simultaneously across rural Washington County. It touched down in an open field with no damage reported.
A tornado touched down and caused extensive damage to a carport and garage. One pine tree was uprooted.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
7 minutes of warning. NWS BOU issued a tornado warning for this county at 23:04 UTC, 7 minutes before the tornado touched down, in force until 23:30 UTC.
The county was under a tornado watch, issued at 19:14 UTC and running to 01:47 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 19:14 UTC | 01:47 UTC | Tornado Watch | BOU |
| 22:18 UTC | 23:00 UTC | Severe Thunderstorm Warning | BOU |
| 22:59 UTC | 23:45 UTC | Severe Thunderstorm Warning | BOU |
| 23:04 UTC | 23:30 UTC | Tornado Warning | BOU |
| 23:27 UTC | 00:00 UTC | Tornado Warning | BOU |
| 00:00 UTC | 02:33 UTC | Flash Flood Watch | BOU |
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 Enhanced Risk, with a 0.10 chance of a tornado within 25 miles. The outlook in force was issued at 19:37 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 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.
Denver, CO (KDEN), 12:00Z
11.2 hours before the tornado, 36 km from the path. May 28, 2018.
- Mixed-layer CAPE
- 69 J/kg
- Mixed-layer CIN
- -104 J/kg
- Surface CAPE
- 179 J/kg
- Mixed-layer LCL
- 854 m above ground
- 0-6 km bulk shear
- 49 kt
- 0-1 km bulk shear
- 1 kt
- 0-1 km storm-relative helicity
- -4 m²/s²
- 0-3 km storm-relative helicity
- 173 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -0.0
- 0-3 km lapse rate
- 5.7 K/km
The surface observations
Yuma (2V6), 54 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 21:19 UTC | 68 | 53.6 | 80° 15 kt | 1012.2 | ||
| 21:34 UTC | 68 | 51.8 | 90° 15 kt | 21 | 1011.9 | |
| 21:59 UTC | 68 | 50 | 80° 18 kt | 24 | 1011.5 | |
| 22:19 UTC | 68 | 48.2 | 70° 18 kt | 22 | 1011.2 | |
| 22:39 UTC | 68 | 46.4 | 80° 20 kt | 1010.8 | ||
| 22:54 UTC | 66.2 | 46.4 | 80° 17 kt | 21 | 1010.5 | -RA |
| 23:14 UTC | 64.4 | 48.2 | 50° 10 kt | 16 | 1011.2 | -VCTSRA |
| 23:39 UTC | 64.4 | 50 | 60° 13 kt | 1010.2 | -VCTSRA | |
| 23:54 UTC | 62.6 | 50 | 70° 13 kt | 1010.8 | +VCTSRA | |
| 00:19 UTC | 60.8 | 46.4 | 100° 10 kt | 24 | 1012.9 | +TSRA |
| 00:39 UTC | 55.4 | 44.6 | 120° 11 kt | 1012.5 | TSRA | |
| 00:59 UTC | 55.4 | 44.6 | 110° 4 kt | 1011.9 | -TSRA |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The Goodland radar (KGLD), 109 km away, was scanning. The volume nearest the touchdown began at 23:08 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 |
|---|---|---|---|---|
| 22:22 UTC | TORNADO | 7 E Thurman | Washington, CO | THERE WAS A TORNADO REPORTED BETWEEN 422 PM AND 430 PM JUST NORTH OF THE LINCOLN-WASHINGTON COUNTY LINE BY THREE DIFFERENT CHASE GROUPS. LASTED 5 TO 8 MINUTES FROM THEIR ACCOUNTS. LOCATION A FEW MILES WEST OF INTERSECTIO |
| 22:25 UTC | HAIL 1.75 | 5 Ese Anton | Washington, CO | |
| 22:47 UTC | HAIL 1.75 | 7 Ssw Arickaree School | Washington, CO | |
| 23:00 UTC | TORNADO | 4 S Arickaree School | Washington, CO | CORRECTS PREVIOUS TORNADO REPORT FROM 4 S ARICKAREE SCHOOL. NUMEROUS REPORTS OR TORNADO IN CORN FIELD. DAMAGE TO CROP LIKELY. ON GROUND FOR SEVERAL MINUTES. THE DURATION OF THE TORNADO EVENT WAS 3 MINUTES. |
| 23:00 UTC | TORNADO | 4 S Arickaree School | Washington, CO | NUMEROUS REPORTS OR TORNADO IN CORN FIELD. DAMAGE TO CROP LIKELY. ON GROUND FOR SEVERAL MINUTES. |
| 23:00 UTC | TORNADO | 7 Ssw Arickaree School | Washington, CO | TWO TORNADOES LASTED 5-7 MINUTES. CHASERS COULD SEE A THIRD OTHER TORNADO AT THE SAME TIME JUST SOUTH OF U.S. 36. THE DURATION OF THE TORNADO EVENT WAS 7 MINUTES. |
| 23:06 UTC | TORNADO | 17 N Flagler | Kit Carson, CO | OFF-DUTY NWS EMPLOYEE REPORTED LANDSPOUT. |
| 23:10 UTC | TORNADO | 13 Sw Cope | Kit Carson, CO | |
| 23:11 UTC | TORNADO | 5 Wsw Cope | Washington, CO | THIS REPORT IS FOR ONE OF THREE TORNADOES ON THE GROUND SIMULTANEOUSLY SOUTHWEST OF COPE BETWEEN 511 AND 539 PM MDT. THIS TORNADO WAS ANTICYCLONIC AND REMAINED OVER AN OPEN FIELD, LASTING 16 MINUTES. THE DURATION OF THE |
| 23:15 UTC | TORNADO | 5 Wsw Cope | Washington, CO | TWO AND POTENTIALLY 3 TORNADOES ON THE GROUND IN OPEN FIELDS. NO DAMAGE REPORTED. BOTH TORNADOES ON THE GROUND FOR SEVERAL MINUTES WITH ONE LASTING NEAR 30 MINUTES. |
| 23:15 UTC | TORNADO | 5 Wsw Cope | Washington, CO | TWO TORNADOES ON THE GROUND IN OPEN FIELD. NO DAMAGE REPORTED. BOTH TORNADOES ON THE GROUND FOR SEVERAL MINUTES. |
| 23:15 UTC | TORNADO | 8 Ene Thurman | Washington, CO | THIS REPORT COVERS 1 OF 3 TORNADOES THAT WERE VISIBLE WITH A THIRD IN OPEN FIELDS SOUTHWEST OF COPE. A CYCLONIC TORNADO FORMED AT 515 AND LASTED FOR 24 MINUTES TOTAL AND CROSSED INTO KIT CARSON COUNTY. NO DAMAGE REPORTED |
| 23:18 UTC | TORNADO | 17 Wsw Joes | Kit Carson, CO | OFF DUTY NWS EMPLOYEE REPORTED A TORNADO. |
| 23:29 UTC | TORNADO | 9 E Thurman | Washington, CO | THIS IS THE THIRD TORNADO VISIBLE SIMULTANEOUSLY SOUTHWEST OF COPE. IT LASTED A FEW MINUTES. THE DURATION OF THE TORNADO EVENT WAS 3 MINUTES. |
| 23:30 UTC | TORNADO | 13 N Seibert | Kit Carson, CO | SPOTTER REPORTED A LANDSPOUT 13 MILES NORTH OF SEIBERT, JUST WEST OF HIGHWAY 59. |
| 23:35 UTC | TORNADO | 11 N Seibert | Kit Carson, CO | CORRECTS PREVIOUS TORNADO REPORT FROM 12 SW KIRK TO 11N SEIBERT. OFF-DUTY NWS EMPLOYEE SIGHTED A LANDSPOUT 11 MILES NORTH OF SEIBERT AT 5:35 PM MDT. |
| 23:35 UTC | TORNADO | 12 Sw Kirk | Kit Carson, CO | OFF-DUTY NWS EMPLOYEE SIGHTED A LANDSPOUT. |
| 23:40 UTC | HAIL 2.5 | 2 W Cope | Washington, CO | |
| 23:42 UTC | TORNADO | Cope | Washington, CO | CORRECTS PREVIOUS TSTM WND GST REPORT FROM COPE. EXTENSIVE DAMAGE TO A CARPORT AND GARAGE IN SOUTHEAST COPE. ONE PINE TREE WAS ALSO UPROOTED. USING EF-SCALE DAMAGE INDICATORS THIS COULD BE IN EXCESS OF 95 MPH. STORM SPOT |
| 23:45 UTC | TSTM WND GST 80 | Cope | Washington, CO | EXTENSIVE DAMAGE TO A CARPORT AND GARAGE IN SOUTHEAST COPE. USING EF-SCALE DAMAGE INDICATORS THIS COULD BE IN EXCESS OF 80 MPH. STORM SPOTTERS IN THE IMMEDIATE AREA DID NOT SEE ANY ROTATION. RADAR EVIDENCE SUGGESTS WET M |
| 00:02 UTC | HAIL 0.5 | 4 Nnw Joes | Yuma, CO | HEAVY RAIN REPORTED TO REDUCED VIS DOWN TO 100 YDS. |
| 00:10 UTC | TORNADO | 13 Sw Cope | Kit Carson, CO | |
| 01:14 UTC | HAIL 0.88 | 5 Ne Idalia | Yuma, CO | HAIL DRIFTING ACROSS THE ROAD. |
| 01:15 UTC | HAIL 1.5 | Bethune | Kit Carson, CO | |
| 01:16 UTC | HAIL 1.25 | Wsw Bethune | Kit Carson, CO | |
| 01:42 UTC | HAIL 1 | Bethune | Kit Carson, CO | QUARTER SIZED HAIL REPORTED BY PUBLIC IN BETHUNE. |
| 01:42 UTC | HEAVY RAIN 1.25 | Bethune | Kit Carson, CO | 1.25 REPORTED WITH 20 MINUTES |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2018 tornado in ColoradoEvery tornado in Colorado since 1950Warnings in force in Colorado nowThe forecast where you are
The other tornadoes of May 28, 2018
28 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| May 28 | 3:06 PM EDT | EF0 | Calhoun, SC | 0.3 | 150 | |||
| May 28 | 1:10 PM MDT | EF0 | Wasatch, UT | 0.3 | 5 | |||
| May 28 | 1:15 PM MDT | EF0 | Jackson, CO | 0.1 | 50 | |||
| May 28 | 2:19 PM CDT | EF0 | Graham, KS | 4.5 | 100 | |||
| May 28 | 2:20 PM CDT | EF0 | Pocahontas, IA | 0.9 | 30 | |||
| May 28 | 3:00 PM MDT | EF0 | Fremont, WY | 0.5 | 20 | |||
| May 28 | 3:15 PM MDT | EF0 | Box Elder, UT | 0.1 | 5 | |||
| May 28 | 3:39 PM MDT | EF0 | Sweetwater, WY | 3.5 | 25 | |||
| May 28 | 4:19 PM MDT | EF0 | Kit Carson, CO | 0.0 | 100 | |||
| May 28 | 4:22 PM MDT | EF0 | Washington, CO | 0.0 | 50 | |||
| May 28 | 5:00 PM MDT | EF0 | Washington, CO | 0.0 | 50 | |||
| May 28 | 5:00 PM MDT | EF0 | Washington, CO | 0.0 | 50 | |||
| May 28 | 5:00 PM MDT | EF0 | Kit Carson, CO | 1.3 | 150 | |||
| May 28 | 5:10 PM MDT | EF0 | Kit Carson, CO | 2.6 | 200 | $60,000 | ||
| May 28 | 5:10 PM MDT | EF0 | Kit Carson, CO | 1.8 | 150 | |||
| May 28 | 5:10 PM MDT | EF0 | Morgan, CO | 0.0 | 50 | |||
| May 28 | 5:15 PM MDT | EF0 | Washington, CO | 3.6 | 100 | |||
| May 28 | 5:23 PM MDT | EF0 | Washington, CO | 0.0 | 50 | |||
| May 28 | 5:26 PM MDT | EF0 | Kit Carson, CO | 0.0 | 150 | |||
| May 28 | 5:29 PM MDT | EF0 | Washington, CO | 0.0 | 50 | |||
| May 28 | 5:34 PM MDT | EF0 | Weld, CO | 0.0 | 50 | |||
| May 28 | 5:35 PM MDT | EF0 | Kit Carson, CO | 0.0 | 100 | |||
| May 28 | 5:37 PM MDT | EF0 | Weld, CO | 0.0 | 50 | |||
| May 28 | 5:42 PM MDT | EF1 | Washington, CO | 0.0 | 50 | |||
| May 28 | 6:24 PM MDT | EF0 | Morgan, CO | 0.0 | 50 | |||
| May 28 | 6:32 PM MDT | EF0 | Morgan, CO | 0.0 | 50 | |||
| May 28 | 7:41 PM CDT | EF0 | Texas, OK | 0.3 | 50 | |||
| May 28 | 8:21 PM CDT | EF1 | Texas, OK | 2.0 | 200 |
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.