Alert archive / Colorado / Tornado Warnings in 2011

Tornado Warning 25, NWS Denver/Boulder, CO

July 2, 2011Washington County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Jul 2, 2011, 5:05 PM MDT for Washington County, Colorado. It was in force for 25 min. 5 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
Jul 2, 2011, 5:05 PM MDT (23:05 UTC)
Expired
Jul 2, 2011, 5:30 PM MDT
In force
25 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon

County Washington County, CO

The radar

The Denver radar (KFTG), 131 km from the middle of the area, began a volume at 23:08 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

TimeReportWhereRemark
Jul 2, 5:11 PM MDTTORNADOAkron, COSTORM PRODUCING PENNY TO NICKEL SIZE HAIL.
Jul 2, 5:22 PM MDTTSTM WND GST 67Akron, COAKRON ASOS REPORTED PEAK GUST OF 67 MPH.
Jul 2, 5:30 PM MDTTSTM WND GST 604 Se Akron, COALSO REPORTED NICKLE SIZE HAIL
Jul 2, 5:38 PM MDTTORNADOSw Akron, CO
Jul 2, 5:39 PM MDTHAIL 0.88Platner, CO

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.

IssuedProductOfficeLasted
Jul 2, 3:20 PM MDTSevere Thunderstorm WatchSPC9 hr

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 11.1 hours before the alert went out and 38 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 12:00Z on 2011-07-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1031 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 12:00Z on 2011-07-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 square meters per square second.193958Sfc1 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
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.

457 
WFUS55 KBOU 022305
TORBOU
COC121-022330-
/O.NEW.KBOU.TO.W.0025.110702T2305Z-110702T2330Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
505 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 530 PM MDT

* AT 506 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 4 MILES
  NORTHEAST OF AKRON. THIS STORM WAS MOVING SOUTH AT 15 MPH.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO PLATNER AND
  AKRON.

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 4028 10300 4008 10301 4008 10325 4028 10324
TIME...MOT...LOC 2306Z 268DEG 11KT 4019 10313

$$
2 follow-up statements
701 
WWUS55 KBOU 022312
SVSBOU

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

COC121-022330-
/O.CON.KBOU.TO.W.0025.000000T0000Z-110702T2330Z/
WASHINGTON CO-
512 PM MDT SAT JUL 2 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 530 PM MDT FOR CENTRAL
WASHINGTON COUNTY...

AT 512 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS STORM WAS
LOCATED 4 MILES NORTHEAST OF AKRON. THIS STORM WAS MOVING SOUTHEAST AT 15
MPH.

LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
PLATNER AND AKRON.

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 4028 10300 4008 10301 4008 10325 4028 10324
TIME...MOT...LOC 2312Z 265DEG 7KT 4019 10314

$$
024 
WWUS55 KBOU 022332
SVSBOU

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

COC121-022342-
/O.EXP.KBOU.TO.W.0025.000000T0000Z-110702T2330Z/
WASHINGTON CO-
532 PM MDT SAT JUL 2 2011

...THE TORNADO WARNING FOR CENTRAL WASHINGTON COUNTY HAS EXPIRED...

THE THUNDERSTORM THAT PROMPTED THE WARNING HAS EXITED THE AREA.

LAT...LON 4028 10300 4008 10301 4008 10325 4028 10324
TIME...MOT...LOC 2312Z 265DEG 7KT 4019 10314

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 2, 12:17 AM MDTSevere Thunderstorm WarningBOULarimer43 min
Jul 2, 1:23 AM MDTSevere Thunderstorm WarningBOULincoln, Washington52 min
Jul 2, 12:16 PM MDTAreal Flood AdvisoryBOUJackson71 hr
Jul 2, 2:14 PM MDTSpecial Weather StatementBOUJefferson31 min
Jul 2, 3:18 PM MDTSpecial Weather StatementBOUDouglas27 min
Jul 2, 3:46 PM MDTSpecial Weather StatementBOULogan29 min
Jul 2, 3:52 PM MDTSevere Thunderstorm WarningBOULogan38 min
Jul 2, 3:54 PM MDTSpecial Weather StatementBOUElbert36 min
Jul 2, 4:22 PM MDTSpecial Weather StatementBOUMorgan23 min
Jul 2, 4:27 PM MDTSpecial Weather StatementBOUAdams33 min
Jul 2, 4:45 PM MDTSevere Thunderstorm WarningBOUAdams30 min
Jul 2, 5:16 PM MDTSevere Thunderstorm WarningBOUAdams, Morgan, Washington59 min
Jul 2, 5:31 PM MDTSevere Thunderstorm WarningBOUWashington44 min
Jul 2, 5:44 PM MDTTornado WarningBOUWashington31 min
Jul 2, 5:49 PM MDTSpecial Weather StatementBOULincoln26 min
Jul 2, 5:58 PM MDTSevere Thunderstorm WarningBOUElbert, Lincoln62 min

Nearby

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