Alert archive / Colorado / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 61, NWS Denver/Boulder, CO

June 6, 2021Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 6, 2021, 4:08 PM MDT for Weld County, Colorado. It was in force for 37 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 6, 2021, 4:08 PM MDT (22:08 UTC)
Expired
Jun 6, 2021, 4:45 PM MDT
In force
37 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Weld County, CO

The radar

The Denver radar (KFTG), 39 km from the middle of the area, began a volume at 22:11 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, 10.1 hours before the alert went out and 110 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 2021-06-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 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 2021-06-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 85 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2939 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
85 m²/s²
0-3 km storm-relative helicity
76 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

696 
WUUS55 KBOU 062208
SVRBOU
COC123-062245-
/O.NEW.KBOU.SV.W.0061.210606T2208Z-210606T2245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
408 PM MDT Sun Jun 6 2021

The National Weather Service in Denver Colorado has issued a

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

* Until 445 PM MDT.

* At 408 PM MDT, a severe thunderstorm was located 4 miles northeast
  of Keenesburg, or 24 miles southeast of Greeley, moving southeast
  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.

* Locations impacted include...
  Keenesburg, Prospect Valley and Roggen. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4002 10461 4016 10456 4029 10443 4030 10422
      4002 10438
TIME...MOT...LOC 2208Z 314DEG 6KT 4015 10446 

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

DANIELSON
1 follow-up statement
500 
WWUS55 KBOU 062241
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
441 PM MDT Sun Jun 6 2021

COC123-062251-
/O.EXP.KBOU.SV.W.0061.000000T0000Z-210606T2245Z/
Weld CO-
441 PM MDT Sun Jun 6 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL WELD COUNTY WILL
EXPIRE AT 445 PM MDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

LAT...LON 4002 10461 4016 10456 4029 10443 4030 10422
      4002 10438
TIME...MOT...LOC 2241Z 314DEG 6KT 4011 10441 

$$

DANIELSON

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 5, 6:59 PM MDTSpecial Weather StatementBOUDouglas46 min
Jun 5, 7:04 PM MDTSevere Thunderstorm WarningBOUDouglas41 min
Jun 6, 12:30 PM MDTAreal Flood AdvisoryBOULarimer90 min
Jun 6, 4:02 PM MDTSevere Thunderstorm WarningBOUMorgan, Weld28 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.