Alert archive / Colorado / Winter Storm Warnings in 2021

Winter Storm Warning 3, NWS Denver/Boulder, CO

February 24, 20217 counties in Colorado

NWS Denver/Boulder, CO issued this winter storm warning at Feb 24, 2021, 10:19 PM MST for 7 counties in Colorado. It was in force for 10 hr. 60 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
Feb 24, 2021, 10:19 PM MST (05:19 UTC)
Expired
Feb 25, 2021, 8:00 AM MST
In force
10 hr
Issued by
NWS Denver/Boulder, CO

Counties Adams County, CO, Arapahoe County, CO, Boulder County, CO, Broomfield County, CO, Denver County, CO, Douglas County, CO, Jefferson County, CO

The radar

The Denver radar (KFTG), 29 km from the middle of the area, began a volume at 05:16 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
Feb 24, 10:19 PM MSTSNOW 72 Nw Golden, COSTILL SNOWING.
Feb 24, 10:26 PM MSTSNOW 6.81 Sw Westminster, CO
Feb 24, 10:28 PM MSTSNOW 7.81 Nnw Louisville, CO
Feb 24, 10:30 PM MSTSNOW 5.32 E Denver, CO2.2 INCHES FELL IN THE PREVIOUS HOUR. UPDATES THE PREVIOUS REPORT AT 2E DENVER.
Feb 24, 10:36 PM MSTSNOW 6.73 Nnw Marshall, CO
Feb 24, 10:49 PM MSTSNOW 8.43 Nne Northglenn, COSTILL SNOWING AT THE TIME OF THE REPORT.
Feb 24, 10:50 PM MSTSNOW 8.32 Nw Golden, COUPDATE TO THE PREVIOUS REPORT 2NW GOLDEN. STORM TOTAL 8.25 INCHES, STILL SNOWING AT THE TIME OF THE REPORT. APPROXIMATELY 1.25 INCHES FELL IN THE LAST 40 MINUTES.
Feb 24, 10:51 PM MSTSNOW 42 Sw Lone Tree, CO
Feb 24, 10:51 PM MSTSNOW 7.53 Ene Arvada, CO
Feb 24, 11:04 PM MSTSNOW 92 Sw Niwot, COREPORT VIA TWITTER.
Feb 24, 11:08 PM MSTSNOW 5.52 Nnw Golden, CO
Feb 24, 11:13 PM MSTSNOW 7.5Englewood, CO
Feb 24, 11:26 PM MSTSNOW 7.11 Nnw Pleasant View, CO1.3 INCHES IN THE PAST HOUR.
Feb 24, 11:30 PM MSTSNOW 81 Ese Mountain View, CO3 INCHES IN THE PAST 2 HOURS.
Feb 24, 11:40 PM MSTSNOW 6.5Aurora, CO
Feb 25, 12:00 AM MSTSNOW 7.11 W Wheat Ridge, CO
Feb 25, 12:05 AM MSTSNOW 8.22 E Denver, CO
Feb 25, 12:07 AM MSTSNOW 7.72 N Aspen Park, CO
Feb 25, 12:25 AM MSTSNOW 9.22 Wsw Louisville, CO
Feb 25, 12:40 AM MSTSNOW 7.23 Sw Aurora, CO
Feb 25, 1:04 AM MSTSNOW 82 S Greenwood Village, CO
Feb 25, 1:15 AM MSTSNOW 9.8Federal Heights, CO
Feb 25, 1:17 AM MSTSNOW 10.81 Ese Thornton, CO
Feb 25, 1:38 AM MSTSNOW 3.71 Nne Evergreen, CO
Feb 25, 2:09 AM MSTSNOW 7.22 Wsw Foxfield, CO
Feb 25, 2:30 AM MSTSNOW 12.81 Nne Highlands Ranch, COPHOTO SHARED VIA FACEBOOK.
Feb 25, 3:00 AM MSTSNOW 8.52 E Broomfield, CO
Feb 25, 3:19 AM MSTSNOW 10.52 Ne Arvada, COSTILL SNOWING AT TIME OF REPORT.
Feb 25, 3:41 AM MSTSNOW 21 Nnw Castle Rock, CO
Feb 25, 4:15 AM MSTSNOW 9.41 Nnw Louisville, CO
Feb 25, 4:21 AM MSTSNOW 3.52 Nne Shaffers Crossing, CO
Feb 25, 4:27 AM MSTSNOW 111 Nnw Federal Heights, CO
Feb 25, 4:35 AM MSTSNOW 5.55 S Barr Lake, CO
Feb 25, 4:43 AM MSTSNOW 12.82 Ese Federal Heights, COSNOW FELL IN 10 HOURS.
Feb 25, 4:46 AM MSTSNOW 121 E Chatfield Reservoir, CO
Feb 25, 4:51 AM MSTSNOW 12.51 Ese Ken Caryl, CO
Feb 25, 4:54 AM MSTSNOW 125 Nne Cherry Hills Vill, CO
Feb 25, 5:00 AM MSTSNOW 4.5Evergreen, CO
Feb 25, 5:00 AM MSTSNOW 8.71 W Brighton, COCOCORAHS STATION CO-AD-204 BRIGHTON 1.9 NNW.
Feb 25, 5:00 AM MSTSNOW 8.83 Ssw Boulder, COSTORM TOTAL SNOW.
Feb 25, 5:00 AM MSTSNOW 9.6Denver Intl Airport, COSNOWFALL THROUGH 5 AM.
Feb 25, 5:01 AM MSTSNOW 131 Ese Littleton, CO
Feb 25, 5:03 AM MSTSNOW 11.53 Wsw Aurora, CO0.59 INCHES OF LIQUID.
Feb 25, 5:05 AM MSTSNOW 13.21 Se Littleton, CO
Feb 25, 5:40 AM MSTSNOW 6.63 Ssw Crescent Village, COCOCORAHS STATION CO-JF-425 GOLDEN 11.8 NW.
Feb 25, 5:42 AM MSTSNOW 13.21 Ese Thornton, COSTORM TOTAL SNOWFALL.
Feb 25, 5:45 AM MSTSNOW 12.22 Ese Denver, CO
Feb 25, 5:47 AM MSTSNOW 9.61 Ese Lafayette, CO
Feb 25, 5:57 AM MSTSNOW 2.63 Ssw Castle Pines, CO
Feb 25, 6:00 AM MSTSNOW 6.54 Wsw Arvada, COCOCORAHS STATION CO-JF-504 ARVADA 3.6 WSW.
Feb 25, 6:00 AM MSTSNOW 8Arvada, CO
Feb 25, 6:00 AM MSTSNOW 8.14 Se Evergreen, COCOCORAHS STATION CO-JF-403 EVERGREEN 3.5 SE.
Feb 25, 6:00 AM MSTSNOW 11.21 Wsw Aurora, COCOCORAHS STATION CO-AR-270 AURORA 0.7 WSW.
Feb 25, 6:00 AM MSTSNOW 15.2Littleton, COCOCORAHS STATION CO-AR-386 LITTLETON 0.1 ESE.
Feb 25, 6:10 AM MSTSNOW 84 W Conifer, CO
Feb 25, 6:25 AM MSTSNOW 5.82 N Longmont, CO
Feb 25, 6:30 AM MSTSNOW 4Longmont, CO
Feb 25, 6:30 AM MSTSNOW 52 Se Lakewood, CO
Feb 25, 6:30 AM MSTSNOW 11.26 N Westminster, CO
Feb 25, 6:30 AM MSTSNOW 13.23 N Cherry Creek Reserv, COCOCORAHS STATION CO-AR-105 DENVER 6.3 SSE.

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 00:00Z, 5.3 hours before the alert went out and 141 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 00:00Z on 2021-02-25Temperature 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 00:00Z on 2021-02-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 31 square meters per square second.1939587897117Sfc1 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
1786 m above ground
0-6 km bulk shear
80 kt
0-1 km storm-relative helicity
31 m²/s²
0-3 km storm-relative helicity
44 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

486 
WWUS45 KBOU 250519
WSWBOU

URGENT - WINTER WEATHER MESSAGE
National Weather Service Denver CO
1019 PM MST Wed Feb 24 2021

.The heaviest snow is falling across the Denver metro area, and will 
only slowly diminish overnight. Travel is discouraged and will be 
difficult.  Slick roads are expected for early morning commuters.

COZ039-040-251330-
/O.UPG.KBOU.WW.Y.0015.000000T0000Z-210225T1500Z/
/O.NEW.KBOU.WS.W.0003.210225T0519Z-210225T1500Z/
Boulder And Jefferson Counties Below 6000 Feet/West Broomfield
County-North Douglas County Below 6000 Feet/Denver/West Adams and
Arapahoe Counties/East Broomfield County-
Including the cities of Boulder, Golden, Highlands Ranch, City of
Denver, Lakewood, Aurora, Arvada, Littleton, Parker, Longmont,
Denver International Airport, and Brighton
1019 PM MST Wed Feb 24 2021

...WINTER STORM WARNING IN EFFECT UNTIL 8 AM MST THURSDAY...

* WHAT...Snow expected. Total snow accumulations between 6 and 10 
  inches, with locally higher amounts possible.

* WHERE...Boulder and the western suburbs of Denver, and Denver.

* WHEN...Until 8 AM MST Thursday.

* IMPACTS...Plan on difficult travel. The hazardous conditions could 
  impact the Thursday morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in 
your vehicle in case of an emergency. The latest road conditions for 
Colorado can be obtained by calling 5 1 1 or by going to www.cotrip.
org

&&

$$

COZ035-036-041-251330-
/O.CON.KBOU.WW.Y.0015.000000T0000Z-210225T1500Z/
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-Elbert/Central and
East Douglas Counties Above 6000 Feet-
Including the cities of Evergreen, Georgetown, Glendevey, Castle
Rock, Nederland, Larkspur, Elbert, Westcreek, Central City, Red
Feather Lakes, Kiowa, Idaho Springs, Estes Park, Bailey, and
Fondis
1019 PM MST Wed Feb 24 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 8 AM MST 
THURSDAY...

* WHAT...Snow expected. Total snow accumulations between 4 to 10 
  inches.

* WHERE...The Northern Front Range Foothills, The Southern Front 
  Range Foothills, and Castle Rock.

* WHEN...Until 8 AM MST Thursday.

* IMPACTS...Plan on slippery road conditions. The hazardous 
  conditions could impact the Thursday morning commute. Roads will 
  likely become slick and hazardous.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. The latest road 
conditions for Colorado can be obtained by calling 5 1 1 or by going 
to www.cotrip.org

&&

$$

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

Barjenbruch
2 follow-up statements
270 
WWUS45 KBOU 250911
WSWBOU

URGENT - WINTER WEATHER MESSAGE
National Weather Service Denver CO
211 AM MST Thu Feb 25 2021

.The heaviest snow is falling across the Denver metro area, and will 
only slowly diminish into the early morning hours.  Travel will be 
difficult and is discouraged. Lighter snow is occurring across the 
rest of the Front Range and adjacent plains.  Slick roads are 
expected for the morning commute.

COZ039-040-251500-
/O.CON.KBOU.WS.W.0003.000000T0000Z-210225T1500Z/
Boulder And Jefferson Counties Below 6000 Feet/West Broomfield
County-North Douglas County Below 6000 Feet/Denver/West Adams and
Arapahoe Counties/East Broomfield County-
Including the cities of Boulder, Golden, Highlands Ranch, City of
Denver, Lakewood, Aurora, Arvada, Littleton, Parker, Longmont,
Denver International Airport, and Brighton
211 AM MST Thu Feb 25 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 8 AM MST THIS 
MORNING...

* WHAT...Snow expected. Total snow accumulations between 7 and 12 
  inches.

* WHERE...Denver, Boulder, and the western suburbs of Denver.

* WHEN...Until 8 AM MST this morning.

* IMPACTS...Plan on difficult travel. The hazardous conditions could 
  impact the Thursday morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in 
your vehicle in case of an emergency. The latest road conditions for 
Colorado can be obtained by calling 5 1 1 or by going to www.cotrip.
org

&&

$$

COZ045>047-251700-
/O.EXB.KBOU.WW.Y.0015.000000T0000Z-210225T1700Z/
Central and East Adams and Arapahoe Counties-North and Northeast
Elbert County Below 6000 Feet/North Lincoln County-Southeast
Elbert County Below 6000 Feet/South Lincoln County-
Including the cities of Hugo, Punkin Center, Karval, Bennett,
Matheson, Limon, Deer Trail, Byers, Agate, Forder, Kutch, and
Leader
211 AM MST Thu Feb 25 2021

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 10 AM MST THIS MORNING...

* WHAT...Snow ongoing. Additional snow accumulations up to two 
  inches, with storm totals of 3 to 7 inches.

* WHERE...Byers, Limon, and Southern Lincoln County.

* WHEN...Until 10 AM MST this morning.

* IMPACTS...Plan on slick and hazardous road conditions.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. The latest road 
conditions for Colorado can be obtained by calling 5 1 1 or by going 
to www.cotrip.org

&&

$$

COZ035-036-041-251500-
/O.CON.KBOU.WW.Y.0015.000000T0000Z-210225T1500Z/
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-Elbert/Central and
East Douglas Counties Above 6000 Feet-
Including the cities of Evergreen, Georgetown, Glendevey, Castle
Rock, Nederland, Larkspur, Elbert, Westcreek, Central City, Red
Feather Lakes, Kiowa, Idaho Springs, Estes Park, Bailey, and
Fondis
211 AM MST Thu Feb 25 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 8 AM MST THIS 
MORNING...

* WHAT...Snow expected. Total snow accumulations between 4 to 10 
  inches.

* WHERE...The Northern Front Range Foothills, The Southern Front 
  Range Foothills, and Castle Rock.

* WHEN...Until 8 AM MST this morning.

* IMPACTS...Plan on slick and hazardous road conditions. The 
  hazardous conditions will impact the Thursday morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. The latest road 
conditions for Colorado can be obtained by calling 5 1 1 or by going 
to www.cotrip.org

&&

$$

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

Barjenbruch
215 
WWUS45 KBOU 251453
WSWBOU

URGENT - WINTER WEATHER MESSAGE
National Weather Service Denver CO
753 AM MST Thu Feb 25 2021

COZ039-040-251600-
/O.EXP.KBOU.WS.W.0003.000000T0000Z-210225T1500Z/
Boulder And Jefferson Counties Below 6000 Feet/West Broomfield
County-North Douglas County Below 6000 Feet/Denver/West Adams and
Arapahoe Counties/East Broomfield County-
Including the cities of Boulder, Golden, Highlands Ranch, City of
Denver, Lakewood, Aurora, Arvada, Littleton, Parker, Longmont,
Denver International Airport, and Brighton
753 AM MST Thu Feb 25 2021

...WINTER STORM WARNING WILL EXPIRE AT 8 AM MST THIS MORNING...

$$

COZ035-036-041-251600-
/O.EXP.KBOU.WW.Y.0015.000000T0000Z-210225T1500Z/
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-Elbert/Central and
East Douglas Counties Above 6000 Feet-
Including the cities of Evergreen, Georgetown, Glendevey, Castle
Rock, Nederland, Larkspur, Elbert, Westcreek, Central City, Red
Feather Lakes, Kiowa, Idaho Springs, Estes Park, Bailey, and
Fondis
753 AM MST Thu Feb 25 2021

...WINTER WEATHER ADVISORY WILL EXPIRE AT 8 AM MST THIS MORNING...

$$

COZ045>047-251700-
/O.CON.KBOU.WW.Y.0015.000000T0000Z-210225T1700Z/
Central and East Adams and Arapahoe Counties-North and Northeast
Elbert County Below 6000 Feet/North Lincoln County-Southeast
Elbert County Below 6000 Feet/South Lincoln County-
Including the cities of Hugo, Punkin Center, Karval, Bennett,
Matheson, Limon, Deer Trail, Byers, Agate, Forder, Kutch, and
Leader
753 AM MST Thu Feb 25 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 AM MST THIS 
MORNING...

* WHAT...Light snow is ongoing. Additional snow accumulations up to 
  1 inch is possible.

* WHERE...Byers, Limon, and Southern Lincoln County.

* WHEN...Until 10 AM MST this morning.

* IMPACTS...Plan on slippery road conditions.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. The latest road 
conditions for Colorado can be obtained by calling 5 1 1 or by going 
to www.cotrip.org

&&

$$

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

Bowen

Nearby

Winter Storm Warnings in Colorado, 2021Every winter storm 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.