Alert archive / Colorado / Tornado Warnings in 2007

Tornado Warning 50, NWS Denver/Boulder, CO

July 12, 2007Weld County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Jul 12, 2007, 3:46 PM MDT for Weld County, Colorado. It was in force for 28 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: Jul 12, 2007, 3:46 PM MDT (21:46 UTC)
Expired: Jul 12, 2007, 4:14 PM MDT
In force: 28 min
Issued by: NWS Denver/Boulder, CO
Area: Counties, with a storm outline in the text

County Weld County, CO

The radar

The Cheyenne radar (KCYS), 62 km from the middle of the area, began a volume at 21:49 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.

Issued	Product	Office	Lasted
Jul 12, 1:03 PM MDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 9.8 hours before the alert went out and 136 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: 156 J/kg
Mixed-layer CIN: -313 J/kg
Mixed-layer LCL: 1625 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 5 m²/s²
0-3 km storm-relative helicity: -53 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

000 
WFUS55 KBOU 122148
TORBOU
COC123-122230-
/O.NEW.KBOU.TO.W.0050.070712T2146Z-070712T2230Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
346 PM MDT THU JUL 12 2007

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

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

* UNTIL 430 PM MDT

* AT 346 PM MDT...LAW ENFORCEMENT REPORTED A TORNADO 1 MILES EAST OF 
  AULT OR ABOUT 12  MILES NORTH NORTHEAST OF GREELEY.  THIS STORM    
  WAS MOVING SOUTH AT 15 MPH.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WINDSOR...
  SEVERANCE...PURCELL...PIERCE...NUNN...LUCERNE...GILL...GALETON...
  EATON...BRIGGSDALE...BARNESVILLE...AULT AND NORTH CENTRAL GREELEY.

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 4078 10417 4081 10489 4047 10493 4042 10419

$$

1 follow-up statement

000 
WWUS55 KBOU 122214
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
411 PM MDT THU JUL 12 2007

COC123-122221-
/O.CAN.KBOU.TO.W.0050.000000T0000Z-070712T2230Z/
WELD CO-
411 PM MDT THU JUL 12 2007

...THE TORNADO WARNING FOR CENTRAL WELD COUNTY IS CANCELLED...

THE THUNDERSTORM THAT PROMPTED THE WARNING HAS WEAKENED AND IS NO 
LONGER EXPECTED TO PRODUCE TORNADIC THUNDERSTORMS.  

ALTHOUGH THE STORM HAS WEAKENED...IT MAY STILL PRODUCE SMALL 
HAIL...LOCALLY HEAVY RAINFALL...WIND GUSTS TO 40 MPH AND DANGEROUS 
CLOUD TO GROUND LIGHTNING.  ADDITIONAL WARNINGS WILL BE ISSUED IF 
THE STORMS IN THE AREA REINTENSIFY.

LAT...LON 4078 10417 4081 10489 4047 10493 4042 10419

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 11, 7:07 PM MDT	Severe Thunderstorm Warning	BOU	Washington	24 min
Jul 11, 8:32 PM MDT	Severe Thunderstorm Warning	BOU	Weld	43 min
Jul 12, 12:50 PM MDT	Severe Thunderstorm Warning	BOU	Larimer	27 min
Jul 12, 1:59 PM MDT	Severe Thunderstorm Warning	BOU	Boulder	46 min
Jul 12, 2:34 PM MDT	Severe Thunderstorm Warning	BOU	Larimer, Weld	41 min
Jul 12, 2:51 PM MDT	Severe Thunderstorm Warning	BOU	Logan, Weld	54 min
Jul 12, 3:03 PM MDT	Severe Thunderstorm Warning	BOU	Larimer, Weld	49 min
Jul 12, 3:16 PM MDT	Severe Thunderstorm Warning	BOU	Douglas, Elbert	25 min
Jul 12, 3:40 PM MDT	Severe Thunderstorm Warning	BOU	Logan, Morgan, Washington, Weld	50 min
Jul 12, 4:25 PM MDT	Severe Thunderstorm Warning	BOU	Morgan	50 min
Jul 12, 4:56 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Arapahoe, Morgan, Washington	49 min

Nearby

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