Alert archive / Colorado / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 112, NWS Denver/Boulder, CO

July 17, 2021Adams County, Morgan County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 17, 2021, 7:11 PM MDT for Adams County, Morgan County, Colorado. It was in force for 34 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 17, 2021, 7:11 PM MDT (01:11 UTC)
Expired
Jul 17, 2021, 7:45 PM MDT
In force
34 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Adams County, CO, Morgan County, CO

The radar

The Denver radar (KFTG), 58 km from the middle of the area, began a volume at 01:13 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 00:00Z, 1.2 hours before the alert went out and 61 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 2021-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 55 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 2021-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -14 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
55 J/kg
Mixed-layer CIN
-39 J/kg
Mixed-layer LCL
3294 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
-14 m²/s²
0-3 km storm-relative helicity
4 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

221 
WUUS55 KBOU 180111
SVRBOU
COC001-087-180145-
/O.NEW.KBOU.SV.W.0112.210718T0111Z-210718T0145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
711 PM MDT Sat Jul 17 2021

The National Weather Service in Denver Colorado has issued a

* Severe Thunderstorm Warning for...
  South central Morgan County in northeastern Colorado...
  Northeastern Adams County in northeastern Colorado...

* Until 745 PM MDT.

* At 711 PM MDT, a severe thunderstorm was located 4 miles west of
  Adena, or 20 miles southwest of Fort Morgan, and is nearly
  stationary.

  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.

* Locations impacted include...
  Adena.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4008 10384 3990 10381 3989 10405 4006 10407
TIME...MOT...LOC 0111Z 099DEG 0KT 4000 10397 

HAIL...1.00IN
WIND...60MPH
 
$$

HIRIS
1 follow-up statement
590 
WWUS55 KBOU 180140
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
740 PM MDT Sat Jul 17 2021

COC001-087-180149-
/O.EXP.KBOU.SV.W.0112.000000T0000Z-210718T0145Z/
Morgan CO-Adams CO-
740 PM MDT Sat Jul 17 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL MORGAN AND
NORTHEASTERN ADAMS COUNTIES WILL EXPIRE AT 745 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.

LAT...LON 4008 10384 3990 10381 3989 10405 4006 10407
TIME...MOT...LOC 0139Z 099DEG 0KT 4000 10397 

$$

HIRIS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 17, 6:01 PM MDTSpecial Weather StatementBOUDenver29 min
Jul 17, 6:42 PM MDTSpecial Weather StatementBOUArapahoe33 min
Jul 17, 6:53 PM MDTSpecial Weather StatementBOUMorgan22 min
Jul 17, 7:06 PM MDTSpecial Weather StatementBOUAdams24 min
Jul 17, 7:37 PM MDTAreal Flood AdvisoryBOUAdams, Morgan113 min
Jul 17, 7:44 PM MDTSpecial Weather StatementBOUMorgan46 min
Jul 17, 8:10 PM MDTSevere Thunderstorm WarningBOULogan, Morgan, Washington50 min
Jul 17, 8:55 PM MDTSpecial Weather StatementBOULogan50 min
Jul 17, 9:13 PM MDTSpecial Weather StatementBOUCrowley47 min
Jul 17, 10:18 PM MDTSpecial Weather StatementBOULincoln42 min
Jul 17, 10:38 PM MDTAreal Flood AdvisoryBOUElbert, Lincoln82 min

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.