Alert archive / Colorado / Tornado Warnings in 2004

Tornado Warning 6, NWS Denver/Boulder, CO

May 20, 2004Morgan County, Weld County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at May 20, 2004, 7:34 PM MDT for Morgan County, Weld County, Colorado. It was in force for 56 min. 29 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: May 20, 2004, 7:34 PM MDT (01:34 UTC)
Expired: May 20, 2004, 8:30 PM MDT
In force: 56 min
Issued by: NWS Denver/Boulder, CO
Area: Counties, with a storm outline in the text

Counties Morgan County, CO, Weld County, CO

The radar

The Denver radar (KFTG), 62 km from the middle of the area, began a volume at 01:35 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
May 20, 7:43 PM MDT	HAIL 0.75	7 W Wiggins, CO
May 20, 7:43 PM MDT	HAIL 0.75	7 W Wiggins, CO
May 20, 7:43 PM MDT	HAIL 0.75	7 W Wiggins, CO
May 20, 7:43 PM MDT	HAIL 0.75	7 W Wiggins, CO
May 20, 7:43 PM MDT	HAIL 0.75	7 W Wiggins, CO
May 20, 7:43 PM MDT	HAIL 0.75	7 W Wiggins, CO
May 20, 7:43 PM MDT	HAIL 0.75	7 W Wiggins, CO
May 20, 7:43 PM MDT	HAIL 0.75	7 W Wiggins, CO
May 20, 7:50 PM MDT	HAIL 0.75	5 W Wiggins, CO	ALONG I-76.
May 20, 7:50 PM MDT	HAIL 0.75	5 W Wiggins, CO	ALONG I-76.
May 20, 7:50 PM MDT	HAIL 0.75	5 W Wiggins, CO	ALONG I-76.
May 20, 7:50 PM MDT	HAIL 0.75	5 W Wiggins, CO	ALONG I-76.
May 20, 7:50 PM MDT	HAIL 0.75	5 W Wiggins, CO	ALONG I-76.
May 20, 7:50 PM MDT	HAIL 0.75	5 W Wiggins, CO	ALONG I-76.
May 20, 7:50 PM MDT	HAIL 0.75	5 W Wiggins, CO	ALONG I-76.
May 20, 7:50 PM MDT	HAIL 0.75	5 W Wiggins, CO	ALONG I-76.
May 20, 8:11 PM MDT	HAIL 1.75	2 N Wiggins, CO
May 20, 8:11 PM MDT	HAIL 1.75	2 N Wiggins, CO
May 20, 8:11 PM MDT	HAIL 1.75	2 N Wiggins, CO
May 20, 8:11 PM MDT	HAIL 1.75	2 N Wiggins, CO
May 20, 8:11 PM MDT	HAIL 1.75	2 N Wiggins, CO
May 20, 8:11 PM MDT	HAIL 1.75	2 N Wiggins, CO
May 20, 8:11 PM MDT	HAIL 1.75	2 N Wiggins, CO
May 20, 8:18 PM MDT	TORNADO	2 N Wiggins, CO	BRIEF TOUCHDOWN.
May 20, 8:18 PM MDT	TORNADO	2 N Wiggins, CO	BRIEF TOUCHDOWN.
May 20, 8:18 PM MDT	TORNADO	2 N Wiggins, CO	BRIEF TOUCHDOWN.
May 20, 8:18 PM MDT	TORNADO	2 N Wiggins, CO	BRIEF TOUCHDOWN.
May 20, 8:18 PM MDT	TORNADO	2 N Wiggins, CO	BRIEF TOUCHDOWN.
May 20, 8:18 PM MDT	TORNADO	2 N Wiggins, CO	BRIEF TOUCHDOWN.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 20, 6:15 PM MDT	Tornado Watch	SPC	5 hr

The nearest sounding before it

Denver, CO (KDNR), launched 00:00Z, 1.6 hours before the alert went out and 96 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: 1364 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 2205 m above ground
0-6 km bulk shear: 60 kt
0-1 km storm-relative helicity: 128 m²/s²
0-3 km storm-relative helicity: 230 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 6.0

Open this sounding in Storm Lab

The text

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

301 
WFUS55 KBOU 210134
TORBOU
COC087-123-210230-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
733 PM MDT THU MAY 20 2004

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* TORNADO WARNING FOR...
  WESTERN MORGAN COUNTY IN NORTHEAST COLORADO
  CENTRAL WELD COUNTY IN NORTHEAST COLORADO

* UNTIL 830 PM MDT

* AT 733 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  THUNDERSTORM WITH A POSSIBLE TORNADO 6 MILES NORTHEAST OF ROGGEN...
  OR ABOUT 26 MILES SOUTHEAST OF GREELEY...MOVING EAST AT 25 MPH.

LOCATIONS IN THE WARNING INCLUDE...BUT ARE NOT LIMITED TO...
GOODRICH...JACKSON RESERVOIR...ORCHARD...RIVERSIDE RESERVOIR...
ROGGEN...WELDONA AND WIGGINS.

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.

THIS STORM HAS HAD A HISTORY OF PRODUCING HAIL UP TO 1.5 INCHES IN 
DIAMETER.

LAT...LON 4025 10446 4010 10434 4008 10385 4052 10380
          4049 10441

$$
RJK

The office that day

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

Issued	Product	Office	Counties	Lasted
May 20, 6:22 PM MDT	Severe Thunderstorm Warning	BOU	Weld	53 min
May 20, 7:15 PM MDT	Severe Thunderstorm Warning	BOU	Weld	60 min
May 20, 8:17 PM MDT	Tornado Warning	BOU	Morgan, Weld	58 min
May 20, 8:56 PM MDT	Tornado Warning	BOU	Washington	49 min

Nearby

Tornado Warnings in Colorado, 2004 Every tornado warning in 2004 Tornadoes in 2004

Sources

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