Alert archive / Colorado / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 99, NWS Denver/Boulder, CO

July 3, 2021Washington County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 3, 2021, 5:29 PM MDT for Washington County, Colorado. It was in force for 31 min. 2 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: Jul 3, 2021, 5:29 PM MDT (23:29 UTC)
Expired: Jul 3, 2021, 6:00 PM MDT
In force: 31 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

County Washington County, CO

The radar

The Goodland radar (KGLD), 125 km from the middle of the area, began a volume at 23:32 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
Jul 3, 5:39 PM MDT	TSTM WND GST 60	10 E Elba, CO	WA153.
Jul 3, 6:01 PM MDT	TSTM WND GST 60	9 E Elba, CO	WA159, BRANCHES BREAKING.

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 3, 3:33 PM MDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 11.5 hours before the alert went out and 37 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2605 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 26 m²/s²
0-3 km storm-relative helicity: 31 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

140 
WUUS55 KBOU 032329
SVRBOU
COC121-040000-
/O.NEW.KBOU.SV.W.0099.210703T2329Z-210704T0000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
529 PM MDT Sat Jul 3 2021

The National Weather Service in Denver Colorado has issued a

* Severe Thunderstorm Warning for...
  East central Washington County in northeastern Colorado...

* Until 600 PM MDT.

* At 529 PM MDT, a severe thunderstorm was located near Otis, or 12
  miles west of Yuma, moving southeast at 15 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* Locations impacted include...
  Otis and Platner. 

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 4000 10280 3995 10280 3988 10305 4016 10316
      4027 10280 4013 10279 4004 10280 4004 10279
      4000 10279
TIME...MOT...LOC 2329Z 331DEG 11KT 4009 10296 

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

RPK

2 follow-up statements

933 
WWUS55 KBOU 032342
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
542 PM MDT Sat Jul 3 2021

COC121-040000-
/O.CON.KBOU.SV.W.0099.000000T0000Z-210704T0000Z/
Washington CO-
542 PM MDT Sat Jul 3 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM MDT
FOR EAST CENTRAL WASHINGTON COUNTY...

At 542 PM MDT, a severe thunderstorm was located 6 miles south of
Otis, or 12 miles southwest of Yuma, moving southeast at 15 mph.

HAZARD...Half dollar size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

Locations impacted include...
Otis and Platner. 

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 4000 10280 3995 10280 3988 10305 4016 10316
      4027 10280 4013 10279 4004 10280 4004 10279
      4000 10279
TIME...MOT...LOC 2342Z 331DEG 11KT 4005 10293 

HAIL...1.25IN
WIND...<50MPH
 
$$

RPK

342 
WWUS55 KBOU 032347
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
547 PM MDT Sat Jul 3 2021

COC121-040000-
/O.CON.KBOU.SV.W.0099.000000T0000Z-210704T0000Z/
Washington CO-
547 PM MDT Sat Jul 3 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM MDT
FOR EAST CENTRAL WASHINGTON COUNTY...

At 547 PM MDT, a severe thunderstorm was located 8 miles south of
Otis, or 12 miles southwest of Yuma, moving southeast at 15 mph.

HAZARD...Tennis ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

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

This severe thunderstorm will remain over mainly rural areas of east
central Washington County, which includes Hyde.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move to a shelter, inside a strong building and away from
windows.

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

&&

LAT...LON 4000 10280 3995 10280 3988 10305 4005 10311
      4015 10281 4013 10279 4004 10280 4004 10279
      4000 10279
TIME...MOT...LOC 2347Z 331DEG 11KT 4004 10292 

HAIL...2.50IN
WIND...60MPH
 
$$

RPK

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 2, 6:36 PM MDT	Special Weather Statement	BOU	Denver	24 min
Jul 2, 6:42 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Weld	33 min
Jul 2, 7:11 PM MDT	Areal Flood Advisory	BOU	Adams	47 min
Jul 2, 7:13 PM MDT	Special Weather Statement	BOU	Denver	32 min
Jul 2, 7:17 PM MDT	Areal Flood Advisory	BOU	Larimer	88 min
Jul 3, 2:03 PM MDT	Areal Flood Advisory	BOU	Larimer	87 min
Jul 3, 2:22 PM MDT	Special Weather Statement	BOU	Weld	38 min
Jul 3, 3:11 PM MDT	Special Weather Statement	BOU	Weld	34 min
Jul 3, 3:23 PM MDT	Severe Thunderstorm Warning	BOU	Weld	37 min
Jul 3, 3:57 PM MDT	Severe Thunderstorm Warning	BOU	Morgan, Weld	33 min
Jul 3, 4:25 PM MDT	Special Weather Statement	BOU	Logan	20 min
Jul 3, 4:34 PM MDT	Special Weather Statement	BOU	Logan	26 min
Jul 3, 4:45 PM MDT	Special Weather Statement	BOU	Morgan	30 min
Jul 3, 4:53 PM MDT	Severe Thunderstorm Warning	BOU	Washington	37 min
Jul 3, 4:59 PM MDT	Severe Thunderstorm Warning	BOU	Logan	31 min
Jul 3, 5:05 PM MDT	Severe Thunderstorm Warning	BOU	Logan	25 min
Jul 3, 5:14 PM MDT	Special Weather Statement	BOU	Elbert	31 min
Jul 3, 5:20 PM MDT	Severe Thunderstorm Warning	BOU	Elbert	25 min
Jul 3, 5:38 PM MDT	Areal Flood Advisory	BOU	Logan	82 min
Jul 3, 5:40 PM MDT	Areal Flood Advisory	BOU	Elbert	95 min
Jul 3, 5:56 PM MDT	Severe Thunderstorm Warning	BOU	Washington	34 min

Nearby

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