Alert archive / Colorado / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 69, NWS Denver/Boulder, CO

June 13, 2021Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 13, 2021, 6:43 PM MDT for Weld County, Colorado. It was in force for 47 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
Jun 13, 2021, 6:43 PM MDT (00:43 UTC)
Expired
Jun 13, 2021, 7:30 PM MDT
In force
47 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Hail
1.5 in
Wind
50.0 mph

County Weld County, CO

The radar

The Cheyenne radar (KCYS), 57 km from the middle of the area, began a volume at 00:43 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, 0.7 hours before the alert went out and 139 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 2021-06-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1095 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 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 2021-06-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -5 square meters per square second.193958Sfc1 km3 km6 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
1095 J/kg
Mixed-layer CIN
-143 J/kg
Mixed-layer LCL
2628 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
-5 m²/s²
0-3 km storm-relative helicity
22 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted.

306 
WUUS55 KBOU 140043
SVRBOU
COC123-140130-
/O.NEW.KBOU.SV.W.0069.210614T0043Z-210614T0130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
643 PM MDT Sun Jun 13 2021

The National Weather Service in Denver Colorado has issued a

* Severe Thunderstorm Warning for...
  North central Weld County in northeastern Colorado...

* Until 730 PM MDT.

* At 643 PM MDT, a severe thunderstorm was located 13 miles west of
  Grover, or 28 miles southeast of Cheyenne, moving east at 10 mph.

  HAZARD...Ping pong ball size hail.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect 
           damage to roofs, siding, windows, and vehicles.

* Locations impacted include...
  Grover.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4062 10427 4074 10462 4089 10458 4087 10423
TIME...MOT...LOC 0043Z 287DEG 8KT 4082 10448 

HAIL...1.50IN
WIND...<50MPH
 
$$

SCHLATTER
2 follow-up statements
347 
WWUS55 KBOU 140108
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
708 PM MDT Sun Jun 13 2021

COC123-140130-
/O.CON.KBOU.SV.W.0069.000000T0000Z-210614T0130Z/
Weld CO-
708 PM MDT Sun Jun 13 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM MDT
FOR NORTH CENTRAL WELD COUNTY...

At 708 PM MDT, a severe thunderstorm was located 9 miles north of
Briggsdale, or 31 miles northeast of Greeley, moving southeast at 20
mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

Locations impacted include...
Grover.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4069 10449 4088 10439 4087 10423 4062 10427
TIME...MOT...LOC 0108Z 298DEG 15KT 4076 10436 

HAIL...1.00IN
WIND...<50MPH
 
$$

SCHLATTER
916 
WWUS55 KBOU 140127
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
727 PM MDT Sun Jun 13 2021

COC123-140137-
/O.EXP.KBOU.SV.W.0069.000000T0000Z-210614T0130Z/
Weld CO-
727 PM MDT Sun Jun 13 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL WELD COUNTY WILL
EXPIRE AT 730 PM MDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

LAT...LON 4069 10449 4088 10439 4087 10423 4062 10427
TIME...MOT...LOC 0127Z 287DEG 8KT 4075 10431 

$$

SCHLATTER

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 13, 6:17 PM MDTSpecial Weather StatementBOUBroomfield28 min
Jun 13, 6:26 PM MDTSpecial Weather StatementBOUDenver34 min
Jun 13, 6:31 PM MDTSevere Thunderstorm WarningBOUWeld29 min
Jun 13, 6:58 PM MDTSevere Thunderstorm WarningBOUWeld32 min
Jun 13, 7:26 PM MDTSevere Thunderstorm WarningBOULarimer, Weld34 min
Jun 13, 7:32 PM MDTSpecial Weather StatementBOULogan43 min
Jun 13, 8:29 PM MDTSpecial Weather StatementBOUMorgan46 min
Jun 13, 8:31 PM MDTSpecial Weather StatementBOULarimer29 min
Jun 13, 9:32 PM MDTSpecial Weather StatementBOUWeld28 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.