Alert archive / Colorado / Tornado Warnings in 2012

Tornado Warning 25, NWS Denver/Boulder, CO

September 27, 2012Douglas County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Sep 27, 2012, 1:15 PM MDT for Douglas County, Colorado. It was in force for 29 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
Sep 27, 2012, 1:15 PM MDT (19:15 UTC)
Expired
Sep 27, 2012, 1:44 PM MDT
In force
29 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon

County Douglas County, CO

The radar

The Denver radar (KFTG), 71 km from the middle of the area, began a volume at 19:14 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 nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 7.3 hours before the alert went out and 160 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 2012-09-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 50 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 12:00Z on 2012-09-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 22 square meters per square second.1939Sfc1 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
50 J/kg
Mixed-layer CIN
-111 J/kg
Mixed-layer LCL
1041 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
22 m²/s²
0-3 km storm-relative helicity
81 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.

522 
WFUS55 KBOU 271915
TORBOU
COC035-272000-
/O.NEW.KBOU.TO.W.0025.120927T1915Z-120927T2000Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
115 PM MDT THU SEP 27 2012

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHERN DOUGLAS COUNTY IN NORTHEAST COLORADO

* UNTIL 200 PM MDT

* AT 115 PM MDT...TRAINED WEATHER SPOTTERS REPORTED A FUNNEL CLOUD 
  NEARLY TOUCHING THE GROUND EAST OF LARKSPUR...OR 23 MILES NORTH OF 
  COLORADO SPRINGS. THIS STORM WAS MOVING EAST AT 10 MPH.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO LARKSPUR.

LAT...LON 3919 10501 3933 10475 3924 10468 3912 10493
      3913 10494
TIME...MOT...LOC 1915Z 250DEG 9KT 3919 10488

$$
1 follow-up statement
056 
WWUS55 KBOU 271944
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
144 PM MDT THU SEP 27 2012

COC035-271953-
/O.CAN.KBOU.TO.W.0025.000000T0000Z-120927T2000Z/
DOUGLAS CO-
144 PM MDT THU SEP 27 2012

...THE TORNADO WARNING FOR SOUTHERN DOUGLAS COUNTY IS CANCELLED...

THE THUNDERSTORM THAT PROMPTED THE WARNING HAS WEAKENED AND IS NO
LONGER EXPECTED TO PRODUCE SEVERE WEATHER.

A BRIEF TORNADO TOUCHDOWN WAS REPORTED BY STORM SPOTTERS ABOUT 6 
MILES EAST OF LARKSPUR AROUND 120 PM.  

LAT...LON 3919 10501 3933 10475 3924 10468 3912 10493
      3913 10494
TIME...MOT...LOC 1943Z 250DEG 9KT 3921 10479

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 26, 6:20 PM MDTAreal Flood AdvisoryBOUWeld85 min
Sep 26, 6:48 PM MDTFlash Flood WarningBOUWeld2 hr
Sep 27, 1:29 PM MDTTornado WarningBOUElbert31 min
Sep 27, 4:40 PM MDTAreal Flood AdvisoryBOUWashington80 min
Sep 27, 5:00 PM MDTSpecial Weather StatementBOUWeld30 min

Nearby

Tornado Warnings in Colorado, 2012Every tornado warning in 2012Tornadoes in 2012

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.