Alert archive / Colorado / High Wind Warnings in 2021

High Wind Warning 9, NWS Denver/Boulder, CO

December 10, 202110 counties in Colorado

NWS Denver/Boulder, CO issued this high wind warning at Dec 10, 2021, 1:56 PM MST for 10 counties in Colorado. It took effect at Dec 11, 2021, 12:00 AM MST. It was in force for 27 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 10, 2021, 1:56 PM MST (20:56 UTC)
In effect from
Dec 11, 2021, 12:00 AM MST
Expired
Dec 12, 2021, 3:14 AM MST
In force
27 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 20:54 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 11, 12:30 AM MSTNON-TSTM WND GST 872 Wsw Brainard Lake, COSUSTAINED WINDS 65 MPH. NIWOT RIDGE D1 STATION AT 12,267 FEET.
Dec 11, 1:10 AM MSTHIGH SUST WINDS 611 Sw Brainard Lake, COPEAK GUST 71 MPH. NIWOT RIDGE SADDLE AT 11,575 FEET.
Dec 11, 10:35 AM MSTNON-TSTM WND GST 681 Ene Berthoud Pass, COAWOS STATION K0CO BERTHOUD PASS. SUSTAINED WIND 53 MPH.
Dec 11, 8:55 PM MSTNON-TSTM WND GST 763 Se Tolland, COAWOS STATION KC99 DAKOTA HILL. SUSTAINED WIND 55 MPH.
Dec 11, 9:35 PM MSTNON-TSTM WND GST 843 Se Tolland, COAWOS STATION KC99 DAKOTA HILL.

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, 8.9 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 2021-12-10Temperature 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 2021-12-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -264 square meters per square second.1939587897117136Sfc1 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
802 m above ground
0-6 km bulk shear
101 kt
0-1 km storm-relative helicity
-264 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

146 
WWUS75 KBOU 102056
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver CO
156 PM MST Fri Dec 10 2021

COZ033>036-111145-
/O.UPG.KBOU.HW.A.0007.211211T1200Z-211212T0000Z/
/O.NEW.KBOU.HW.W.0009.211211T0700Z-211212T1900Z/
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
156 PM MST Fri Dec 10 2021

...HIGH WIND WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO NOON MST 
SUNDAY...

* WHAT...West winds 35 to 45 mph with gusts up to 80 mph expected.

* 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 Midnight tonight to Noon 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. Expect considerable blowing 
  and drifting snow over the high mountain passes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain in the lower levels of your home during the windstorm, and 
avoid windows. Watch for falling debris and tree limbs. Use caution 
if you must drive.

&&

$$

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

Entrekin
5 follow-up statements
553 
WWUS75 KBOU 110353
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver CO
853 PM MST Fri Dec 10 2021

COZ033>036-111600-
/O.CON.KBOU.HW.W.0009.211211T0700Z-211212T1900Z/
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
853 PM MST Fri Dec 10 2021

...HIGH WIND WARNING REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO NOON 
MST SUNDAY...

* WHAT...West winds 35 to 45 mph with gusts up to 80 mph expected.

* 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 Midnight tonight to Noon MST Sunday.

* IMPACTS...Damaging winds will blow down trees and power lines. 
  Power outages may occur. Travel will be difficult, especially for 
  high profile vehicles. Expect considerable blowing and drifting 
  snow over the high mountain passes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Watch for falling debris and tree limbs. Use caution if you must 
drive.

&&

$$

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

Danielson
533 
WWUS75 KBOU 111151
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver CO
451 AM MST Sat Dec 11 2021

COZ033>036-112000-
/O.CON.KBOU.HW.W.0009.000000T0000Z-211212T1900Z/
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
451 AM MST Sat Dec 11 2021

...HIGH WIND WARNING REMAINS IN EFFECT UNTIL NOON MST SUNDAY...

* WHAT...West winds 35 to 50 mph with gusts up to 85 mph expected.

* 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 Noon 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.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Watch for falling debris and tree limbs. Use caution if you must 
drive.

&&

$$

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

RJK
218 
WWUS75 KBOU 112047
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver CO
147 PM MST Sat Dec 11 2021

COZ033>036-121200-
/O.CON.KBOU.HW.W.0009.000000T0000Z-211212T1900Z/
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
147 PM MST Sat Dec 11 2021

...HIGH WIND WARNING REMAINS IN EFFECT UNTIL NOON MST SUNDAY...

* WHAT...West winds 35 to 50 mph with gusts up to 85 mph expected.

* 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 Noon MST Sunday.

* IMPACTS...Damaging winds will blow down trees and power lines. 
  Power outages may occur. Travel will be difficult, especially for 
  high profile vehicles. Expect considerable blowing and drifting 
  snow over the high mountain passes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Watch for falling debris and tree limbs. Use caution if you must 
drive.

&&

$$

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

Hiris
722 
WWUS75 KBOU 120245
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver/Boulder CO
745 PM MST Sat Dec 11 2021

COZ036-120345-
/O.CAN.KBOU.HW.W.0009.000000T0000Z-211212T1900Z/
Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet-
Including Bailey, Central City, Evergreen, Georgetown, 
Idaho Springs, and Westcreek
745 PM MST Sat Dec 11 2021

...HIGH WIND WARNING IS CANCELLED...

Winds are weakening and no longer expected to meet warning
criteria. These areas can still expect gusts 35 to 55 mph at 
times through midday Sunday.

$$

COZ033>035-121300-
/O.CON.KBOU.HW.W.0009.000000T0000Z-211212T1900Z/
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-
Including Cameron Pass, Laramie and Medicine Bow Mountains, 
Rabbit Ears Range, Rocky Mountain National Park, 
Willow Creek Pass, Berthoud Pass, Breckenridge, 
East Slopes Mosquito Range, East Slopes Southern Gore Range, 
Eisenhower Tunnel, Indian Peaks, Kenosha Mountains, Mount Evans, 
Williams Fork Mountains, Winter Park, Estes Park, Glendevey, 
Nederland, and Red Feather Lakes
745 PM MST Sat Dec 11 2021

...HIGH WIND WARNING REMAINS IN EFFECT UNTIL NOON MST SUNDAY...

* WHAT...West winds 15 to 30 mph with localized gusts up to 75 mph
  possible.

* WHERE...The Northern Front Range Foothills, The Mountains of 
  Summit County, the Mosquito Range, and the Indian Peaks and 
  Rocky Mountain National Park and the Medicine Bow Range.

* WHEN...Until noon MST Sunday.

* IMPACTS...Strong winds will blow unsecured objects around. Tree
  limbs could be blown down and a few power outages may result.
  Travel will be difficult for high profile vehicles. Areas of
  blowing snow will be likely over high mountain passes and
  roadways. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Strong winds may lead to property damage. Hazardous driving
conditions due to powerful cross winds will pose a serious risk
for drivers, especially for light weight and high profile
vehicles. Loose outdoor items should be brought inside or secured
properly.

&&

$$
888 
WWUS75 KBOU 121014
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver CO
314 AM MST Sun Dec 12 2021

COZ033>035-121115-
/O.CAN.KBOU.HW.W.0009.000000T0000Z-211212T1900Z/
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-
Including the cities of Glendevey, East Slopes Mosquito Range,
Estes Park, Indian Peaks, Nederland, Eisenhower Tunnel, Rocky
Mountain National Park, East Slopes Southern Gore Range, Mount
Evans, Laramie and Medicine Bow Mountains, Red Feather Lakes,
Cameron Pass, Breckenridge, Kenosha Mountains, Winter Park,
Williams Fork Mountains, Willow Creek Pass, Rabbit Ears Range,
and Berthoud Pass
314 AM MST Sun Dec 12 2021

...HIGH WIND WARNING IS CANCELLED...

The threat has ended.

$$

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

RJK

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 10, 4:05 AM MSTHigh Wind WatchBOUBoulder, Clear Creek, Douglas, Gilpin, Grand, Jackson and 4 more10 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.