Alert archive / Colorado / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 119, NWS Denver/Boulder, CO

August 12, 2021Elbert County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Aug 12, 2021, 7:49 PM MDT for Elbert County, Colorado. It was in force for 26 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
Aug 12, 2021, 7:49 PM MDT (01:49 UTC)
Expired
Aug 12, 2021, 8:15 PM MDT
In force
26 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Elbert County, CO

The radar

The Denver radar (KFTG), 78 km from the middle of the area, began a volume at 01:53 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, 1.8 hours before the alert went out and 74 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 2021-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 616 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 2021-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 1 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
616 J/kg
Mixed-layer CIN
-65 J/kg
Mixed-layer LCL
2322 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
1 m²/s²
0-3 km storm-relative helicity
98 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

486 
WUUS55 KBOU 130149
SVRBOU
COC039-130215-
/O.NEW.KBOU.SV.W.0119.210813T0149Z-210813T0215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
749 PM MDT Thu Aug 12 2021

The National Weather Service in Denver Colorado has issued a

* Severe Thunderstorm Warning for...
  East central Elbert County in east central Colorado...

* Until 815 PM MDT.

* At 748 PM MDT, a severe thunderstorm was located 8 miles southeast
  of Agate, or 10 miles northwest of Limon, moving southwest at 5
  mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees. Hail damage to 
           vehicles is expected.

* This severe thunderstorm will remain over mainly rural areas of
  east central Elbert County, including the following locations...
  Cedar Point.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3938 10373 3928 10387 3937 10393 3948 10378
TIME...MOT...LOC 0148Z 040DEG 3KT 3938 10383 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

BARJENBRUCH
1 follow-up statement
943 
WWUS55 KBOU 130211
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
811 PM MDT Thu Aug 12 2021

COC039-130221-
/O.EXP.KBOU.SV.W.0119.000000T0000Z-210813T0215Z/
Elbert CO-
811 PM MDT Thu Aug 12 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL ELBERT COUNTY
WILL EXPIRE AT 815 PM MDT...
                
The storm which prompted the warning has weakened below severe 
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However heavy 
rain and minor flooding of low lying areas can be expected with this 
thunderstorm.

LAT...LON 3938 10373 3928 10387 3937 10393 3948 10378
TIME...MOT...LOC 0211Z 040DEG 3KT 3937 10384 

$$

BARJENBRUCH

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 6:10 PM MDTSpecial Weather StatementBOUElbert50 min
Aug 12, 7:01 PM MDTSpecial Weather StatementBOUElbert29 min
Aug 12, 10:51 PM MDTAreal Flood AdvisoryBOUWashington84 min
Aug 12, 11:09 PM MDTSpecial Weather StatementBOUDouglas36 min
Aug 12, 11:21 PM MDTAreal Flood AdvisoryBOUDouglas20 min
Aug 12, 11:41 PM MDTFlash Flood WarningBOUDouglas94 min
Aug 13, 12:38 AM MDTAreal Flood AdvisoryBOUDouglas, Jefferson82 min
Aug 13, 1:20 PM MDTAreal Flood AdvisoryBOUGrand85 min
Aug 13, 1:42 PM MDTAreal Flood AdvisoryBOUGrand2 hr
Aug 13, 2:27 PM MDTFlash Flood WarningBOUGrand2 hr
Aug 13, 3:36 PM MDTAreal Flood AdvisoryBOUGrand69 min
Aug 13, 3:53 PM MDTAreal Flood AdvisoryBOULarimer2 hr
Aug 13, 5:39 PM MDTFlash Flood WarningBOUGrand2 hr

Nearby

Severe Thunderstorm Warnings in Colorado, 2021Every severe thunderstorm warning in 2021

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.