Alert archive / Colorado / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 85, NWS Denver/Boulder, CO

July 6, 2012Logan County, Washington County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 6, 2012, 9:46 PM MDT for Logan County, Washington County, Colorado. It was in force for 44 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 6, 2012, 9:46 PM MDT (03:46 UTC)
Expired
Jul 6, 2012, 10:30 PM MDT
In force
44 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Hail
1.5 in
Wind
50.0 mph

Counties Logan County, CO, Washington County, CO

The radar

The Denver radar (KFTG), 138 km from the middle of the area, began a volume at 03:49 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 00:00Z, 3.8 hours before the alert went out and 64 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 00:00Z on 2012-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 180 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 00:00Z on 2012-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 51 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
180 J/kg
Mixed-layer CIN
-101 J/kg
Mixed-layer LCL
1123 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
51 m²/s²
0-3 km storm-relative helicity
291 m²/s²
Significant tornado parameter
0.1
Supercell composite
3.8

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

990 
WUUS55 KBOU 070346
SVRBOU
COC075-121-070430-
/O.NEW.KBOU.SV.W.0085.120707T0346Z-120707T0430Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
946 PM MDT FRI JUL 6 2012

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTH CENTRAL WASHINGTON COUNTY IN NORTHEAST COLORADO
  SOUTH CENTRAL LOGAN COUNTY IN NORTHEAST COLORADO

* UNTIL 1030 PM MDT

* AT 947 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING PING PONG BALL SIZE HAIL. 
  THIS STORM WAS LOCATED 7 MILES WEST OF BURDETT...OR 15 MILES
  NORTHEAST OF AKRON...MOVING NORTHWEST AT 15 MPH.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO MERINO AND
  BURDETT.

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 4053 10343 4058 10293 4029 10290 4027 10316
TIME...MOT...LOC 0347Z 153DEG 13KT 4035 10308
WIND...HAIL <50MPH 1.50IN

$$
2 follow-up statements
578 
WWUS55 KBOU 070410
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
1010 PM MDT FRI JUL 6 2012

COC075-121-070430-
/O.CON.KBOU.SV.W.0085.000000T0000Z-120707T0430Z/
WASHINGTON CO-LOGAN CO-
1010 PM MDT FRI JUL 6 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 PM MDT
FOR SOUTH CENTRAL LOGAN AND NORTH CENTRAL WASHINGTON COUNTIES...

AT 1009 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING PING PONG BALL SIZE HAIL. 
THIS STORM WAS LOCATED 9 MILES WEST OF BURDETT...OR 16 MILES SOUTH OF
STERLING...MOVING NORTHWEST AT 15 MPH.  VERY HEAVY RAIN IS ALSO 
EXPECTED WITH THIS STORM WITH LOCALIZED FLOODING POSSIBLE OVER LOW 
LYING AREAS. 

LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
MERINO AND BURDETT.

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 4053 10343 4058 10293 4029 10290 4027 10316
TIME...MOT...LOC 0409Z 154DEG 11KT 4041 10312
WIND...HAIL <50MPH 1.50IN

$$
272 
WWUS55 KBOU 070429
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
1029 PM MDT FRI JUL 6 2012

COC075-121-070438-
/O.EXP.KBOU.SV.W.0085.000000T0000Z-120707T0430Z/
WASHINGTON CO-LOGAN CO-
1029 PM MDT FRI JUL 6 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL LOGAN AND NORTH
CENTRAL WASHINGTON COUNTIES WILL EXPIRE AT 1030 PM MDT...

THE THUNDERSTORM THAT PROMPTED THE WARNING HAS WEAKENED AND IS NO 
LONGER EXPECTED TO PRODUCE SEVERE WEATHER. HEAVY RAIN AND GUSTY 
WINDS TO 45 MPH CAN STILL BE EXPECTED WITH THIS STORM. 

LAT...LON 4053 10343 4058 10293 4029 10290 4027 10316
TIME...MOT...LOC 0428Z 190DEG 16KT 4046 10305

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 6, 6:29 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe, Elbert43 min
Jul 6, 6:57 PM MDTSevere Thunderstorm WarningBOUMorgan, Washington50 min
Jul 6, 8:26 PM MDTAreal Flood AdvisoryBOUMorgan, Washington94 min
Jul 6, 8:41 PM MDTFlash Flood WatchBOUArapahoe, Boulder, Broomfield, Clear Creek, Douglas, Elbert and 8 more32 hr
Jul 6, 8:56 PM MDTFlash Flood WarningBOULarimer3 hr
Jul 6, 9:01 PM MDTAreal Flood AdvisoryBOUWashington59 min
Jul 6, 9:06 PM MDTFlash Flood WarningBOUBoulder97 min
Jul 6, 11:20 PM MDTAreal Flood AdvisoryBOULogan, Washington, Weld115 min
Jul 7, 3:08 PM MDTAreal Flood AdvisoryBOUBoulder97 min
Jul 7, 3:23 PM MDTAreal Flood AdvisoryBOUClear Creek97 min
Jul 7, 3:41 PM MDTFlash Flood WarningBOUBoulder94 min
Jul 7, 3:45 PM MDTFlash Flood WarningBOUBoulder90 min
Jul 7, 3:57 PM MDTFlash Flood WarningBOUClear Creek93 min
Jul 7, 4:19 PM MDTAreal Flood AdvisoryBOUAdams, Arapahoe, Denver, Douglas, Jefferson86 min
Jul 7, 4:30 PM MDTAreal Flood AdvisoryBOUBoulder90 min
Jul 7, 4:36 PM MDTAreal Flood AdvisoryBOULarimer84 min
Jul 7, 4:49 PM MDTAreal Flood AdvisoryBOULarimer86 min
Jul 7, 4:53 PM MDTFlash Flood WarningBOUBoulder106 min
Jul 7, 5:01 PM MDTAreal Flood AdvisoryBOUBoulder119 min
Jul 7, 5:35 PM MDTAreal Flood AdvisoryBOUBoulder85 min
Jul 7, 5:59 PM MDTAreal Flood AdvisoryBOULarimer91 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.