Alert archive / Colorado / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 76, NWS Denver/Boulder, CO

June 27, 20125 counties in Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 27, 2012, 4:49 PM MDT for 5 counties in Colorado. It was in force for 41 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
Jun 27, 2012, 4:49 PM MDT (22:49 UTC)
Expired
Jun 27, 2012, 5:30 PM MDT
In force
41 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Adams County, CO, Arapahoe County, CO, Morgan County, CO, Washington County, CO, Weld County, CO

The radar

The Denver radar (KFTG), 66 km from the middle of the area, began a volume at 22:49 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 nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 10.8 hours before the alert went out and 48 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 2012-06-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 12:00Z on 2012-06-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -20 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3667 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
-20 m²/s²
0-3 km storm-relative helicity
23 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.

041 
WUUS55 KBOU 272249
SVRBOU
COC001-005-087-121-123-272330-
/O.NEW.KBOU.SV.W.0076.120627T2249Z-120627T2330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
449 PM MDT WED JUN 27 2012

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN WASHINGTON COUNTY IN NORTHEAST COLORADO
  SOUTHERN MORGAN COUNTY IN NORTHEAST COLORADO
  NORTHEASTERN ARAPAHOE COUNTY IN NORTHEAST COLORADO
  EASTERN ADAMS COUNTY IN NORTHEAST COLORADO
  SOUTH CENTRAL WELD COUNTY IN NORTHEAST COLORADO

* UNTIL 530 PM MDT

* AT 449 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS UP TO ABOUT
  60 MPH.  THIS STORM WAS LOCATED NEAR LEADER...OR 30 MILES SOUTHWEST
  OF FORT MORGAN...MOVING NORTHEAST AT 30 MPH.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO COTTONWOOD
  VALLEY...WIGGINS...TWELVE-MILE CORNER...SHAMROCK...LEADER...LAST
  CHANCE...HOYT...GARY...ADENA SCHOOL AND ADENA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

STRONG AND DAMAGING WINDS ARE LIKELY FROM THIS STORM...BUT THERE WILL
BE LITTLE RAIN. HOWEVER...THERE MAY BE AREAS OF REDUCED VISIBILITIES
IN BLOWING DUST. TAKE COVER IN A STURDY STRUCTURE UNTIL THE STORM
PASSES.

IF SEVERE WEATHER APPROACHES YOUR AREA...GO INSIDE A STURDY SHELTER
AWAY FROM CREEK BEDS AND OTHER FLOOD-PRONE AREAS. REMEMBER...A SEVERE
THUNDERSTORM CAN PRODUCE LARGE DAMAGING HAIL...DAMAGING WINDS IN
EXCESS OF 58 MPH...DEADLY LIGHTNING...AND VERY HEAVY RAIN.

&&

LAT...LON 4009 10357 3983 10370 3973 10340 3956 10362
      3987 10444 4031 10425
TIME...MOT...LOC 2249Z 213DEG 27KT 3991 10402
WIND...HAIL 60MPH <.75IN

$$
1 follow-up statement
900 
WWUS55 KBOU 272326
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
526 PM MDT WED JUN 27 2012

COC001-005-087-121-123-272337-
/O.EXP.KBOU.SV.W.0076.000000T0000Z-120627T2330Z/
WASHINGTON CO-MORGAN CO-ARAPAHOE CO-ADAMS CO-WELD CO-
526 PM MDT WED JUN 27 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL WELD...EASTERN
ADAMS...NORTHEASTERN ARAPAHOE...SOUTHERN MORGAN AND SOUTHWESTERN
WASHINGTON COUNTIES WILL EXPIRE AT 530 PM MDT...

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

LAT...LON 4009 10357 3983 10370 3973 10340 3956 10362
      3987 10444 4031 10425
TIME...MOT...LOC 2327Z 213DEG 27KT 4015 10382

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 27, 10:19 AM MDTRed Flag WarningBOUBoulder, Clear Creek, Douglas, Gilpin, Jefferson, Larimer and 1 more10 hr
Jun 27, 4:10 PM MDTFlash Flood WarningBOULarimer2 hr
Jun 27, 4:19 PM MDTSevere Thunderstorm WarningBOUMorgan, Washington41 min
Jun 27, 5:18 PM MDTSevere Thunderstorm WarningBOUWashington27 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2012Every severe thunderstorm warning 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.