Alert archive / Colorado / Tornado Warnings in 2001

Tornado Warning 27, NWS Denver/Boulder, CO

June 20, 2001Adams County, Denver County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Jun 20, 2001, 7:11 PM MDT for Adams County, Denver County, Colorado. It was in force for 34 min. 5 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Jun 20, 2001, 7:11 PM MDT (01:11 UTC)
Expired: Jun 20, 2001, 7:45 PM MDT
In force: 34 min
Issued by: NWS Denver/Boulder, CO
Area: Whole counties

Counties Adams County, CO, Denver County, CO

The radar

The Denver radar (KFTG), 6 km from the middle of the area, began a volume at 01:12 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

Time	Report	Where	Remark
Jun 20, 7:16 PM MDT	Tornado F0	Brighton, CO	A small tornado touched down but did no damage.
Jun 20, 7:25 PM MDT	Tornado F0	Brighton, CO	A small tornado touched down but did no damage.
Jun 20, 7:33 PM MDT	Hail 2	Denver Intl Arpt, CO	Large hail punched at least 14,000 holes and cracks in the flat roofs of several buildings at Denver International Airport. In addition, 93 planes and hundreds of cars were damaged. Approximately 100 flights were canceled, stranding 1500 travelers. The air
Jun 20, 7:45 PM MDT	Thunderstorm Wind 52 E	Watkins, CO	Strong winds caused a truck to rollover along Interstate 70, just east of Watkins. No injuries were reported.
Jun 20, 7:50 PM MDT	Hail 0.75	Bennett, CO

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Denver, CO (KDNR), launched 00:00Z, 1.2 hours before the alert went out and 118 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 484 J/kg
Mixed-layer CIN: -46 J/kg
Mixed-layer LCL: 1925 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: -40 m²/s²
0-3 km storm-relative helicity: 207 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.5

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WFUS55 KBOU 210112
TORDEN
COC001-031-210145-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
711 PM MDT WED JUN 20 2001

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* TORNADO WARNING FOR...
  WESTERN ADAMS COUNTY IN NORTHEAST COLORADO
  NORTHEASTERN DENVER COUNTY IN NORTHEAST COLORADO

* UNTIL 745 PM MDT

* AT 711 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  THUNDERSTORM WITH A POSSIBLE TORNADO 9 MILES NORTH OF DENVER
  INTERNATIONAL AIRPORT...OR ABOUT 22 MILES NORTHEAST OF DENVER...
  MOVING SOUTHEAST AT 25 MPH.

LOCATIONS IN THE WARNING INCLUDE...BUT ARE NOT LIMITED TO...NORTH
CENTRAL AURORA AND DENVER INTERNATIONAL AIRPORT.

IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER IN A NEARBY REINFORCED
BUILDING. AS A LAST RESORT...SEEK SHELTER IN A CULVERT...DITCH OR LOW
SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

LAT...LON 3999 10478k 3976 10472 3982 10455 4001 10468

COOPER

The office that day

Everything else NWS Denver/Boulder, CO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 20, 6:25 PM MDT	Tornado Warning	BOU	Lincoln	35 min
Jun 20, 6:32 PM MDT	Severe Thunderstorm Warning	BOU	Weld	43 min
Jun 20, 7:02 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Denver	43 min
Jun 20, 7:02 PM MDT	Severe Thunderstorm Warning	BOU	Weld	43 min
Jun 20, 7:15 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	45 min
Jun 20, 7:32 PM MDT	Tornado Warning	BOU	Adams, Arapahoe, Denver	28 min
Jun 20, 7:47 PM MDT	Tornado Warning	BOU	Adams, Arapahoe, Denver	33 min
Jun 20, 8:08 PM MDT	Tornado Warning	BOU	Arapahoe, Elbert	37 min
Jun 20, 8:33 PM MDT	Tornado Warning	BOU	Elbert	37 min
Jun 20, 9:11 PM MDT	Severe Thunderstorm Warning	BOU	Elbert	29 min

Nearby

Tornado Warnings in Colorado, 2001 Every tornado warning in 2001 Tornadoes in 2001

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.