Alert archive / Colorado / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 89, NWS Denver/Boulder, CO

July 30, 2012Douglas County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 30, 2012, 3:12 PM MDT for Douglas County, Colorado. It was in force for 22 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 30, 2012, 3:12 PM MDT (21:12 UTC)
Expired
Jul 30, 2012, 3:34 PM MDT
In force
22 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon

County Douglas County, CO

The radar

The Denver radar (KFTG), 47 km from the middle of the area, began a volume at 21:13 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, 9.2 hours before the alert went out and 147 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 2012-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 36 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 2012-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 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
36 J/kg
Mixed-layer CIN
-260 J/kg
Mixed-layer LCL
2058 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
48 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.

752 
WUUS55 KBOU 302112
SVRBOU
COC035-302145-
/O.NEW.KBOU.SV.W.0089.120730T2112Z-120730T2145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
312 PM MDT MON JUL 30 2012

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN DOUGLAS COUNTY IN NORTHEAST COLORADO...

* UNTIL 345 PM MDT

* AT 309 PM MDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM
  CAPABLE OF PRODUCING HALF DOLLAR SIZE HAIL. THIS STORM WAS LOCATED
  NEAR SEDALIA...OR 24 MILES SOUTH OF DENVER...AND MOVING EAST AT 25
  MPH.

* LOCATIONS IMPACTED INCLUDE...
  PARKER...CASTLE ROCK...THE PINERY...FRANKTOWN...BEVERLY HILLS...
  SURREY RIDGE AND SILVER HEIGHTS. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS IN EXCESS OF 60 MPH...
DESTRUCTIVE HAIL...DEADLY LIGHTNING AND VERY HEAVY RAIN. FOR YOUR
PROTECTION...MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE
INTO AREAS WHERE WATER COVERS THE ROAD.

&&

LAT...LON 3938 10495 3948 10498 3955 10467 3937 10467
TIME...MOT...LOC 2109Z 265DEG 20KT 3941 10493 

$$
1 follow-up statement
395 
WWUS55 KBOU 302134
SVSBOU

SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 333 PM 
MDT MON JUL 30 2012

COC035-302143-
/O.CAN.KBOU.SV.W.0089.000000T0000Z-120730T2145Z/
DOUGLAS CO-
334 PM MDT MON JUL 30 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN DOUGLAS COUNTY
IS CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSE AN IMMEDIATE THREAT TO LIFE OR
PROPERTY. THEREFORE THE WARNING HAS BEEN CANCELLED.  HOWEVER HEAVY 
RAIN IS STILL POSSIBLE WITH THIS THUNDERSTORM.

LAT...LON 3938 10495 3947 10498 3954 10467 3936 10467
TIME...MOT...LOC 2133Z 265DEG 20KT 3941 10493 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 30, 2:09 PM MDTSpecial Weather StatementBOUJefferson36 min
Jul 30, 2:30 PM MDTSpecial Weather StatementBOUGrand30 min
Jul 30, 3:04 PM MDTSpecial Weather StatementBOUDouglas26 min
Jul 30, 3:27 PM MDTFlash Flood WarningBOUBoulder78 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.