Alert archive / Colorado / Tornado Warnings in 2021

Tornado Warning 27, NWS Denver/Boulder, CO

June 7, 2021Weld County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Jun 7, 2021, 5:07 PM MDT for Weld County, Colorado. It was in force for 23 min. 4 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jun 7, 2021, 5:07 PM MDT (23:07 UTC)
Expired: Jun 7, 2021, 5:30 PM MDT
In force: 23 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.0 in

County Weld County, CO

The radar

The Denver radar (KFTG), 50 km from the middle of the area, began a volume at 23:08 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.

What was reported inside it

Time	Report	Where	Remark
Jun 7, 5:10 PM MDT	TORNADO	4 Ne Firestone, CO	WELL DEVELOPED TORNADO REPORTED BY NUMEROUS TRAINED WEATHER SPOTTERS.
Jun 7, 5:22 PM MDT	TORNADO	4 Wsw Platteville, CO	DAMAGE TO A METAL SHED. MINOR TO MODERATE ROOF DAMAGE TO HOUSES POSSIBLE AT THIS LOCATION.
Jun 7, 5:24 PM MDT	TORNADO	3 Wsw Platteville, CO	TORNADO DAMAGE AT HIGHWAY 66 AND WELD COUNTY ROAD 21. POWER LINES AND POWER POLES DOWN. STRUCTURE FIRE DUE TO DOWNED POWER LINES.
Jun 7, 5:32 PM MDT	TORNADO	3 Nw Of Platteville, CO	TORNADO DISSIPATED AT THIS TIME.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 11.1 hours before the alert went out and 144 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 17 J/kg
Mixed-layer CIN: -372 J/kg
Mixed-layer LCL: 2991 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: -1 m²/s²
0-3 km storm-relative helicity: -2 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

842 
WFUS55 KBOU 072307
TORBOU
COC123-072330-
/O.NEW.KBOU.TO.W.0027.210607T2307Z-210607T2330Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Denver CO
507 PM MDT Mon Jun 7 2021

The National Weather Service in Denver Colorado has issued a

* Tornado Warning for...
  Southwestern Weld County in northeastern Colorado...

* Until 530 PM MDT.
    
* At 507 PM MDT, a severe thunderstorm capable of producing a tornado
  was located near Platteville, or 15 miles southwest of Greeley,
  moving northeast at 10 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Expect damage to mobile homes, roofs, and vehicles.

* Locations impacted include...
  Firestone, Frederick, Fort Lupton, Milliken, Dacono, Mead,
  Platteville and Gilcrest.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4005 10499 4030 10497 4033 10472 4007 10470
TIME...MOT...LOC 2307Z 233DEG 7KT 4022 10489 

TORNADO...RADAR INDICATED
HAIL...0.00IN

$$

RJK

1 follow-up statement

759 
WWUS55 KBOU 072316
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
516 PM MDT Mon Jun 7 2021

COC123-072330-
/O.CON.KBOU.TO.W.0027.000000T0000Z-210607T2330Z/
Weld CO-
516 PM MDT Mon Jun 7 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 530 PM MDT FOR
SOUTHWESTERN WELD COUNTY...
    
At 516 PM MDT, a confirmed tornado was located near Platteville, or
16 miles southwest of Greeley, moving northeast at 10 mph.

HAZARD...Damaging tornado.

SOURCE...Weather spotters confirmed tornado.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

Locations impacted include...
Firestone, Frederick, Mead, Platteville and Gilcrest. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. TAKE COVER NOW! Move to a
basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.

&&

LAT...LON 4009 10493 4024 10497 4032 10479 4032 10477
      4012 10472
TIME...MOT...LOC 2316Z 207DEG 8KT 4020 10487 

TORNADO...OBSERVED
HAIL...0.00IN

$$

RJK

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 7, 5:24 PM MDT	Tornado Warning Tornado observed	BOU	Weld	36 min

Nearby

Tornado Warnings in Colorado, 2021 Every tornado warning in 2021 Tornadoes 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.