Alert archive / Colorado / High Wind Warnings in 2021

High Wind Warning 8, NWS Denver/Boulder, CO

December 4, 202110 counties in Colorado

NWS Denver/Boulder, CO issued this high wind warning at Dec 4, 2021, 2:41 PM MST for 10 counties in Colorado. It took effect at Dec 4, 2021, 11:00 PM MST. It was in force for 12 hr. 5 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Dec 4, 2021, 2:41 PM MST (21:41 UTC)
In effect from
Dec 4, 2021, 11:00 PM MST
Expired
Dec 5, 2021, 11:00 AM MST
In force
12 hr
Issued by
NWS Denver/Boulder, CO

Counties Boulder County, CO, Clear Creek County, CO, Douglas County, CO, Gilpin County, CO, Grand County, CO, Jackson County, CO, Jefferson County, CO, Larimer County, CO, Park County, CO, Summit County, CO

The radar

The Denver radar (KFTG), 94 km from the middle of the area, began a volume at 21:41 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

TimeReportWhereRemark
Dec 5, 1:44 AM MSTNON-TSTM WND GST 851 N Georgetown, COMESONET STATION CO162 I-70 GEORGETOWN LAKE STATION ELEVATION: 8468 FT.
Dec 5, 3:55 AM MSTNON-TSTM WND GST 771 Ene Berthoud Pass, COAWOS STATION K0CO BERTHOUD PASS STATION ELEVATION: 11704 FT.
Dec 5, 5:36 AM MSTNON-TSTM WND GST 701 N Glen Haven, COMESONET STATION EW4490 GLEN HAVEN STATION ELEVATION: 7798 FT.
Dec 5, 5:55 AM MSTNON-TSTM WND GST 823 Se Tolland, COAWOS STATION KC99 DAKOTA HILL STATION ELEVATION: 10938 FT.
Dec 5, 9:01 AM MSTNON-TSTM WND GST 804 Ne Nederland, COPUBLIC REPORTED A MEASURED WIND GUST TO 80 MPH. WIND GUSTS ARE STILL 70 TO 75 MPH.

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, 9.7 hours before the alert went out and 206 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 2021-12-04Temperature 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 2021-12-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 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
2166 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
42 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

343 
WWUS75 KBOU 042141
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver CO
241 PM MST Sat Dec 4 2021

COZ033>036-050945-
/O.UPG.KBOU.HW.A.0006.211205T0900Z-211205T1800Z/
/O.NEW.KBOU.HW.W.0008.211205T0600Z-211205T1800Z/
South and East Jackson/Larimer/North and Northeast
Grand/Northwest Boulder Counties Above 9000 Feet-South and
Southeast Grand/West Central and Southwest Boulder/Gilpin/Clear
Creek/Summit/North and West Park Counties Above 9000 Feet-Larimer
and Boulder Counties Between 6000 and 9000 Feet-Jefferson and
West Douglas Counties Above 6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet-
Including the cities of Winter Park, Westcreek, Rocky Mountain
National Park, Central City, Red Feather Lakes, Breckenridge,
Bailey, Williams Fork Mountains, Evergreen, Georgetown,
Glendevey, Indian Peaks, Nederland, Eisenhower Tunnel, East
Slopes Southern Gore Range, Mount Evans, Cameron Pass, East
Slopes Mosquito Range, Berthoud Pass, Kenosha Mountains, Estes
Park, Willow Creek Pass, Laramie and Medicine Bow Mountains,
Idaho Springs, and Rabbit Ears Range
241 PM MST Sat Dec 4 2021

...HIGH WIND WARNING IN EFFECT FROM 11 PM THIS EVENING TO 11 AM MST 
SUNDAY...

* WHAT...West winds 25 to 40 mph with gusts up to 80 mph possible.

* WHERE...Jefferson and West Douglas Counties Above 6000 
  Feet/Gilpin/Clear Creek/Northeast Park Counties Below 9000 Feet, 
  South and Southeast Grand/West Central and Southwest 
  Boulder/Gilpin/Clear Creek/Summit/North and West Park Counties 
  Above 9000 Feet, Larimer and Boulder Counties Between 6000 and 
  9000 Feet and South and East Jackson/Larimer/North and Northeast 
  Grand/Northwest Boulder Counties Above 9000 Feet Counties.

* WHEN...From 11 PM this evening to 11 AM MST Sunday.

* IMPACTS...Damaging winds may blow down trees and power lines. 
  Power outages are possible. Gusty winds will blow around unsecured 
  objects and a few power outages may result.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Winds this strong can make driving difficult, especially for high 
profile vehicles. Use extra caution.

&&

$$

For more information from the National Weather Service, visit 
https://weather.gov/bou

Danielson
2 follow-up statements
287 
WWUS75 KBOU 050356
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver CO
856 PM MST Sat Dec 4 2021

COZ033>036-051300-
/O.CON.KBOU.HW.W.0008.211205T0600Z-211205T1800Z/
South and East Jackson/Larimer/North and Northeast
Grand/Northwest Boulder Counties Above 9000 Feet-South and
Southeast Grand/West Central and Southwest Boulder/Gilpin/Clear
Creek/Summit/North and West Park Counties Above 9000 Feet-Larimer
and Boulder Counties Between 6000 and 9000 Feet-Jefferson and
West Douglas Counties Above 6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet-
Including the cities of Winter Park, Westcreek, Rocky Mountain
National Park, Central City, Red Feather Lakes, Breckenridge,
Bailey, Williams Fork Mountains, Evergreen, Georgetown,
Glendevey, Indian Peaks, Nederland, Eisenhower Tunnel, East
Slopes Southern Gore Range, Mount Evans, Cameron Pass, East
Slopes Mosquito Range, Berthoud Pass, Kenosha Mountains, Estes
Park, Willow Creek Pass, Laramie and Medicine Bow Mountains,
Idaho Springs, and Rabbit Ears Range
856 PM MST Sat Dec 4 2021

...HIGH WIND WARNING REMAINS IN EFFECT UNTIL 11 AM MST SUNDAY...

* WHAT...West winds 25 to 40 mph with gusts up to 85 mph. The 
  strongest winds will occur Sunday morning.

* WHERE...Jefferson and West Douglas Counties Above 6000 
  Feet/Gilpin/Clear Creek/Northeast Park Counties Below 9000 Feet, 
  South and Southeast Grand/West Central and Southwest 
  Boulder/Gilpin/Clear Creek/Summit/North and West Park Counties 
  Above 9000 Feet, Larimer and Boulder Counties Between 6000 and 
  9000 Feet and South and East Jackson/Larimer/North and Northeast 
  Grand/Northwest Boulder Counties Above 9000 Feet Counties.

* WHEN...Until 11 AM MST Sunday.

* IMPACTS...Damaging winds will blow down trees and power lines. 
  Widespread power outages are expected. Travel will be difficult, 
  especially for high profile vehicles. Gusty winds will blow around 
  unsecured objects and a few power outages may result.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Winds this strong can make driving difficult, especially for high 
profile vehicles. Use extra caution.

&&

$$

For more information from the National Weather Service, visit 
https://weather.gov/bou

Entrekin
017 
WWUS75 KBOU 051232
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver CO
532 AM MST Sun Dec 5 2021

COZ033>036-051800-
/O.CON.KBOU.HW.W.0008.000000T0000Z-211205T1800Z/
South and East Jackson/Larimer/North and Northeast
Grand/Northwest Boulder Counties Above 9000 Feet-South and
Southeast Grand/West Central and Southwest Boulder/Gilpin/Clear
Creek/Summit/North and West Park Counties Above 9000 Feet-Larimer
and Boulder Counties Between 6000 and 9000 Feet-Jefferson and
West Douglas Counties Above 6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet-
Including the cities of Winter Park, Westcreek, Rocky Mountain
National Park, Central City, Red Feather Lakes, Breckenridge,
Bailey, Williams Fork Mountains, Evergreen, Georgetown,
Glendevey, Indian Peaks, Nederland, Eisenhower Tunnel, East
Slopes Southern Gore Range, Mount Evans, Cameron Pass, East
Slopes Mosquito Range, Berthoud Pass, Kenosha Mountains, Estes
Park, Willow Creek Pass, Laramie and Medicine Bow Mountains,
Idaho Springs, and Rabbit Ears Range
532 AM MST Sun Dec 5 2021

...HIGH WIND WARNING REMAINS IN EFFECT UNTIL 11 AM MST THIS 
MORNING...

* WHAT...West winds 25 to 40 mph with gusts up to 85 mph. The 
  strongest winds will occur Sunday morning.

* WHERE...Jefferson and West Douglas Counties Above 6000 
  Feet/Gilpin/Clear Creek/Northeast Park Counties Below 9000 Feet, 
  South and Southeast Grand/West Central and Southwest 
  Boulder/Gilpin/Clear Creek/Summit/North and West Park Counties 
  Above 9000 Feet, Larimer and Boulder Counties Between 6000 and 
  9000 Feet and South and East Jackson/Larimer/North and Northeast 
  Grand/Northwest Boulder Counties Above 9000 Feet Counties.

* WHEN...Until 11 AM MST this morning.

* IMPACTS...Gusty winds will blow around unsecured objects and a few 
  power outages may result.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Winds this strong can make driving difficult, especially for high 
profile vehicles. Use extra caution.

&&

$$

For more information from the National Weather Service, visit 
https://weather.gov/bou

AD

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 4, 2:49 AM MSTHigh Wind WatchBOUBoulder, Clear Creek, Douglas, Gilpin, Grand, Jackson and 4 more12 hr

Nearby

High Wind Warnings in Colorado, 2021Every high wind 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.