Alert archive / Colorado / Tornado Warnings in 2007

Tornado Warning 18, NWS Denver/Boulder, CO

May 3, 2007Weld County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at May 3, 2007, 7:21 PM MDT for Weld County, Colorado. It was in force for 24 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
May 3, 2007, 7:21 PM MDT (01:21 UTC)
Expired
May 3, 2007, 7:45 PM MDT
In force
24 min
Issued by
NWS Denver/Boulder, CO
Area
Counties, with a storm outline in the text

County Weld County, CO

The radar

The Denver radar (KFTG), 49 km from the middle of the area, began a volume at 01:24 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.

The watch it was issued in

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

IssuedProductOfficeLasted
May 3, 4:17 PM MDTSevere Thunderstorm WatchSPC6 hr
May 3, 6:43 PM MDTTornado WatchSPC5 hr

The nearest sounding before it

Denver, CO (KDNR), launched 00:00Z, 1.4 hours before the alert went out and 101 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-pSkew-T log-p diagram, Denver, CO at 00:00Z on 2007-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 394 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 00:00Z on 2007-05-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 209 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
394 J/kg
Mixed-layer CIN
-118 J/kg
Mixed-layer LCL
2658 m above ground
0-6 km bulk shear
73 kt
0-1 km storm-relative helicity
209 m²/s²
0-3 km storm-relative helicity
338 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.2

Open this sounding in Storm Lab

The text

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

000 
WFUS55 KBOU 040121
TORBOU
COC123-040145-
/O.NEW.KBOU.TO.W.0018.070504T0121Z-070504T0145Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
721 PM MDT THU MAY 3 2007

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTH CENTRAL WELD COUNTY IN NORTHEAST COLORADO

* UNTIL 745 PM MDT

* AT 721 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 6 MILES EAST OF
  PROSPECT VALLEY...OR ABOUT 29 MILES SOUTHWEST OF FORT MORGAN. THIS
  STORM WAS MOVING EAST AT 20 MPH.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO ROGGEN...
  RIVERSIDE RESERVOIR AND PROSPECT VALLEY.

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 4032 10445 4001 10443 4001 10416 4033 10417

$$
1 follow-up statement
000 
WWUS55 KBOU 040146
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
745 PM MDT THU MAY 3 2007

COC123-040155-
/O.EXP.KBOU.TO.W.0018.000000T0000Z-070504T0145Z/
WELD CO-
745 PM MDT THU MAY 3 2007

...THE TORNADO WARNING FOR SOUTH CENTRAL WELD COUNTY EXPIRED AT 745
PM MDT...

THE THUNDERSTORM THAT PROMPTED THE WARNING WAS ALONG THE 
WELD...MORGAN COUNTY LINE MOVING EASTWARD INTO WESTERN MORGAN COUNTY.

A TORNADO WATCH REMAINS IN EFFECT UNTIL MIDNIGHT MDT FRIDAY MORNING
FOR NORTHEAST COLORADO.

LAT...LON 4032 10445 4001 10443 4001 10416 4033 10417

$$

The office that day

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

IssuedProductOfficeCountiesLasted
May 3, 6:11 PM MDTTornado WarningBOUWeld49 min
May 3, 6:50 PM MDTTornado WarningBOUWeld40 min
May 3, 7:04 PM MDTTornado WarningBOUMorgan41 min
May 3, 7:27 PM MDTTornado WarningBOUWeld48 min
May 3, 7:41 PM MDTTornado WarningBOUMorgan49 min
May 3, 8:12 PM MDTSevere Thunderstorm WarningBOULogan, Weld48 min
May 3, 8:28 PM MDTSevere Thunderstorm WarningBOUMorgan47 min
May 4, 3:32 PM MDTSnow AdvisoryBOUBoulder, Grand, Jackson, Larimer12 hr

Nearby

Tornado Warnings in Colorado, 2007Every tornado warning in 2007Tornadoes in 2007

Sources

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