Alert archive / Colorado / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 91, NWS Denver/Boulder, CO

July 31, 2012Douglas County, Elbert County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 31, 2012, 2:51 PM MDT for Douglas County, Elbert 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
Jul 31, 2012, 2:51 PM MDT (20:51 UTC)
Expired
Jul 31, 2012, 3:20 PM MDT
In force
29 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Hail
1.0 in
Wind
70.0 mph

Counties Douglas County, CO, Elbert County, CO

The radar

The Denver radar (KFTG), 40 km from the middle of the area, began a volume at 20:52 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, 8.9 hours before the alert went out and 117 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 2012-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 26 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 2012-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 63 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
26 J/kg
Mixed-layer CIN
-414 J/kg
Mixed-layer LCL
2225 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
63 m²/s²
0-3 km storm-relative helicity
69 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.

196 
WUUS55 KBOU 312051
SVRBOU
COC035-039-312130-
/O.NEW.KBOU.SV.W.0091.120731T2051Z-120731T2130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
251 PM MDT TUE JUL 31 2012

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHWESTERN ELBERT COUNTY IN EAST CENTRAL COLORADO
  NORTHEASTERN DOUGLAS COUNTY IN NORTHEAST COLORADO

* UNTIL 330 PM MDT

* AT 251 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING ONE INCH DIAMETER HAIL...
  AND DESTRUCTIVE WINDS UP TO ABOUT 70 MPH.  THIS STORM WAS LOCATED
  NEAR THE PINERY...OR 23 MILES SOUTHEAST OF DENVER...MOVING EAST AT
  30 MPH.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO THE
  PINERY...PONDEROSA PARK...PARKER...KIOWA...FRANKTOWN AND ELIZABETH.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3956 10422 3928 10429 3927 10453 3936 10479
      3956 10479
TIME...MOT...LOC 2051Z 268DEG 26KT 3945 10471
WIND...HAIL 70MPH 1.00IN

$$
1 follow-up statement
033 
WWUS55 KBOU 312120
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
320 PM MDT TUE JUL 31 2012

COC035-039-312130-
/O.CAN.KBOU.SV.W.0091.000000T0000Z-120731T2130Z/
ELBERT CO-DOUGLAS CO-
320 PM MDT TUE JUL 31 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN DOUGLAS AND
NORTHWESTERN ELBERT COUNTIES IS CANCELLED...

THE THUNDERSTORM THAT PROMPTED THE WARNING HAS WEAKENED AND IS NO 
LONGER EXPECTED TO PRODUCE SEVERE WEATHER. HEAVY RAIN...PEA SIZED 
HAIL AND WIND GUSTS TO 50 MPH ARE STILL POSSIBLE WITH THIS STORM.



LAT...LON 3956 10422 3928 10429 3927 10453 3936 10479
      3956 10479
TIME...MOT...LOC 2120Z 268DEG 26KT 3946 10444

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 30, 6:18 PM MDTSevere Thunderstorm WarningBOUWashington27 min
Jul 31, 1:03 PM MDTSpecial Weather StatementBOUBroomfield27 min
Jul 31, 1:39 PM MDTSpecial Weather StatementBOUDenver51 min
Jul 31, 2:13 PM MDTSpecial Weather StatementBOUDenver32 min
Jul 31, 3:28 PM MDTSevere Thunderstorm WarningBOUArapahoe, Elbert31 min
Jul 31, 4:43 PM MDTSpecial Weather StatementBOULincoln47 min
Jul 31, 5:39 PM MDTSpecial Weather StatementBOULincoln36 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.