Alert archive / Colorado / Tornado Warnings in 2011

Tornado Warning 26, NWS Denver/Boulder, CO

July 2, 2011Washington County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Jul 2, 2011, 5:44 PM MDT for Washington County, Colorado. It was in force for 31 min. 1 report 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: Jul 2, 2011, 5:44 PM MDT (23:44 UTC)
Expired: Jul 2, 2011, 6:15 PM MDT
In force: 31 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon

County Washington County, CO

The radar

The Denver radar (KFTG), 126 km from the middle of the area, began a volume at 23:45 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
Jul 2, 6:06 PM MDT	HAIL 1	8 Se Akron, CO	ALSO HEAVY RAIN. ESTIMATED 1 INCH IN 30 MINUTES.

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
Jul 2, 3:20 PM MDT	Severe Thunderstorm Watch	SPC	9 hr

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 11.7 hours before the alert went out and 22 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: 1031 J/kg
Mixed-layer CIN: -97 J/kg
Mixed-layer LCL: 1074 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 10 m²/s²
0-3 km storm-relative helicity: 96 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 4.9

Open this sounding in Storm Lab

The text

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

471 
WFUS55 KBOU 022344
TORBOU
COC121-030015-
/O.NEW.KBOU.TO.W.0026.110702T2344Z-110703T0015Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
544 PM MDT SAT JUL 2 2011

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

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

* UNTIL 615 PM MDT

* AT 544 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO OVER CENTRAL
  WASHINGTON COUNTY...OR 9 MILES SOUTH OF AKRON. THIS STORM WAS
  MOVING EAST AT 15 MPH.

* THE SEVERE THUNDERSTORM WILL REMAIN OVER MAINLY RURAL AREAS OF THE
  WARNED COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4013 10301 3994 10301 3993 10326 4012 10326
TIME...MOT...LOC 2344Z 265DEG 11KT 4003 10315

$$

2 follow-up statements

175 
WWUS55 KBOU 022350 RRA
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
550 PM MDT SAT JUL 2 2011

COC121-030015-
/O.CON.KBOU.TO.W.0026.000000T0000Z-110703T0015Z/
WASHINGTON CO-
550 PM MDT SAT JUL 2 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 615 PM MDT FOR CENTRAL
WASHINGTON COUNTY...

AT 551 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS STORM WAS
LOCATED OVER CENTRAL WASHINGTON COUNTY...OR 10 MILES SOUTHEAST OF
AKRON. THIS STORM WAS MOVING EAST AT 15 MPH.

THE SEVERE THUNDERSTORM WILL REMAIN OVER MAINLY RURAL AREAS OF THE
WARNED COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4013 10301 3994 10301 3993 10326 4012 10326
TIME...MOT...LOC 2351Z 265DEG 11KT 4003 10310

$$

103 
WWUS55 KBOU 030013
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
613 PM MDT SAT JUL 2 2011

COC121-030024-
/O.EXP.KBOU.TO.W.0026.000000T0000Z-110703T0015Z/
WASHINGTON CO-
613 PM MDT SAT JUL 2 2011

...THE TORNADO WARNING FOR CENTRAL WASHINGTON COUNTY WILL EXPIRE AT
615 PM MDT...

THE THUNDERSTORM THAT PROMPTED THE WARNING HAS WEAKENED.

LAT...LON 4013 10301 3994 10301 3993 10326 4012 10326
TIME...MOT...LOC 0014Z 265DEG 11KT 4004 10301

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 2, 12:17 AM MDT	Severe Thunderstorm Warning	BOU	Larimer	43 min
Jul 2, 1:23 AM MDT	Severe Thunderstorm Warning	BOU	Lincoln, Washington	52 min
Jul 2, 12:16 PM MDT	Areal Flood Advisory	BOU	Jackson	71 hr
Jul 2, 2:14 PM MDT	Special Weather Statement	BOU	Jefferson	31 min
Jul 2, 3:18 PM MDT	Special Weather Statement	BOU	Douglas	27 min
Jul 2, 3:46 PM MDT	Special Weather Statement	BOU	Logan	29 min
Jul 2, 3:52 PM MDT	Severe Thunderstorm Warning	BOU	Logan	38 min
Jul 2, 3:54 PM MDT	Special Weather Statement	BOU	Elbert	36 min
Jul 2, 4:22 PM MDT	Special Weather Statement	BOU	Morgan	23 min
Jul 2, 4:27 PM MDT	Special Weather Statement	BOU	Adams	33 min
Jul 2, 4:45 PM MDT	Severe Thunderstorm Warning	BOU	Adams	30 min
Jul 2, 5:05 PM MDT	Tornado Warning	BOU	Washington	25 min
Jul 2, 5:16 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Morgan, Washington	59 min
Jul 2, 5:31 PM MDT	Severe Thunderstorm Warning	BOU	Washington	44 min
Jul 2, 5:49 PM MDT	Special Weather Statement	BOU	Lincoln	26 min
Jul 2, 5:58 PM MDT	Severe Thunderstorm Warning	BOU	Elbert, Lincoln	62 min

Nearby

Tornado Warnings in Colorado, 2011 Every tornado warning in 2011 Tornadoes in 2011

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.