Alert archive / Colorado / Winter Storm Warnings in 2022

Winter Storm Warning 9, NWS Denver/Boulder, CO

November 17, 20225 counties in Colorado

NWS Denver/Boulder, CO issued this winter storm warning at Nov 17, 2022, 8:34 AM MST for 5 counties in Colorado. It was in force for 24 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
Nov 17, 2022, 8:34 AM MST (15:34 UTC)
Expired
Nov 18, 2022, 9:00 AM MST
In force
24 hr
Issued by
NWS Denver/Boulder, CO

Counties Boulder County, CO, Broomfield County, CO, Jefferson County, CO, Larimer County, CO, Weld County, CO

The radar

The Denver radar (KFTG), 64 km from the middle of the area, began a volume at 15:35 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
Nov 17, 11:00 AM MSTSNOW 1.51 E Superior, CO
Nov 17, 11:00 AM MSTSNOW 4.81 E Superior, COCORRECTS PREVIOUS SNOW REPORT FROM 1 E SUPERIOR.
Nov 17, 11:02 AM MSTSNOW 2.81 Nnw Genesee, CO
Nov 17, 11:03 AM MSTSNOW 1.33 Ssw Boulder, CO
Nov 17, 11:39 AM MSTSNOW 1.11 S Greeley, CO
Nov 17, 11:57 AM MSTSNOW 1.52 Ne Arvada, CO
Nov 17, 12:07 PM MSTSNOW 12 N Longmont, CO
Nov 17, 12:15 PM MSTSNOW 33 Wnw Arvada, CO
Nov 17, 1:15 PM MSTSNOW 4.31 Nnw Genesee, CO
Nov 17, 2:05 PM MSTSNOW 1.54 Ene Nederland, CO
Nov 17, 2:11 PM MSTSNOW 2.32 Ssw Estes Park, CO.
Nov 17, 2:11 PM MSTSNOW 2.32 Ssw Estes Park, CO
Nov 17, 2:18 PM MSTSNOW 21 Ssw Arvada, CO
Nov 17, 2:24 PM MSTSNOW 2.71 Nne Evergreen, CO
Nov 17, 2:47 PM MSTSNOW 11 Nnw Louisville, CO
Nov 17, 2:59 PM MSTSNOW 41 Ssw Crescent Village, CO.
Nov 17, 2:59 PM MSTSNOW 41 Ssw Crescent Village, CO
Nov 17, 3:00 PM MSTSNOW 3.53 Ssw Boulder, COCORRECTS PREVIOUS SNOW REPORT FROM 3 SSW BOULDER.
Nov 17, 4:15 PM MSTSNOW 5.51 Nnw Genesee, CO
Nov 17, 5:00 PM MSTSNOW 4.33 Ssw Boulder, CO00Z STORM TOTAL AT WFO BOULDER.
Nov 17, 5:26 PM MSTSNOW 2.81 Nw Niwot, CO
Nov 17, 7:54 PM MSTSNOW 1.53 Wsw Fort Collins, CO
Nov 17, 7:54 PM MSTSNOW 5Superior, COESTIMATED REPORT VIA FACEBOOK. THIS INCLUDES THE AM SNOWFALL.
Nov 17, 7:55 PM MSTSNOW 43 N Marshall, CO.
Nov 17, 7:55 PM MSTSNOW 43 N Marshall, CO
Nov 17, 7:57 PM MSTSNOW 2.55 Nw Lyons, CO.
Nov 17, 7:57 PM MSTSNOW 2.55 Nw Lyons, CO
Nov 17, 8:00 PM MSTSNOW 3.52 Ne Arvada, CO
Nov 17, 8:00 PM MSTSNOW 62 Nw Boulder, CO.
Nov 17, 8:00 PM MSTSNOW 62 Nw Boulder, CO
Nov 17, 8:04 PM MSTSNOW 5Lyons, COREPORT VIA FACEBOOK.
Nov 17, 8:05 PM MSTSNOW 2.21 Sw Westminster, CO
Nov 17, 8:05 PM MSTSNOW 6Golden, COREPORT VIA FACEBOOK.
Nov 17, 8:13 PM MSTSNOW 3Lakewood, COREPORT VIA FACEBOOK.
Nov 17, 8:18 PM MSTSNOW 3.5Boulder, COREPORT VIA TWITTER.
Nov 17, 8:20 PM MSTSNOW 4Masonville, COREPORT VIA FACEBOOK.
Nov 17, 8:21 PM MSTSNOW 13 N Niwot, COREPORT VIA TWITTER.
Nov 17, 8:25 PM MSTSNOW 21 Ene Columbine, COREPORT VIA FACEBOOK.
Nov 17, 8:25 PM MSTSNOW 3.31 Ne Boulder, CO.
Nov 17, 8:25 PM MSTSNOW 3.31 Ne Boulder, CO
Nov 17, 8:27 PM MSTSNOW 2.73 W Fort Collins, COREPORT VIA TWITTER.
Nov 17, 8:30 PM MSTSNOW 7.51 Nnw Genesee, CO
Nov 17, 8:33 PM MSTSNOW 3.11 Nnw Louisville, CO
Nov 17, 8:42 PM MSTSNOW 3Longmont, COREPORT VIA FACEBOOK. LOCATION APPROXIMATE.
Nov 17, 8:57 PM MSTSNOW 7.13 Wnw Arvada, COSTORM TOTAL SNOWFALL SO FAR. SNOWING AT THE TIME OF THE REPORT.
Nov 17, 8:58 PM MSTSNOW 7.13 Ssw Boulder, COREPORT VIA TWITTER.
Nov 17, 9:00 PM MSTSNOW 2.41 Nw Broomfield, CO.
Nov 17, 9:00 PM MSTSNOW 2.41 Nw Broomfield, CO
Nov 17, 9:00 PM MSTSNOW 41 Ssw Arvada, CO.
Nov 17, 9:00 PM MSTSNOW 41 Ssw Arvada, CO
Nov 17, 9:20 PM MSTSNOW 3.54 Ene Nederland, CO
Nov 17, 9:20 PM MSTSNOW 8.81 Nw Golden, COREPORT AND PHOTO VIA TWITTER.
Nov 17, 9:21 PM MSTSNOW 2Poudre Park, CO.
Nov 17, 9:21 PM MSTSNOW 2Poudre Park, CO
Nov 17, 9:31 PM MSTSNOW 8.51 Nnw Genesee, CO
Nov 17, 9:38 PM MSTSNOW 1.52 S Loveland, CO.
Nov 17, 9:38 PM MSTSNOW 1.52 S Loveland, CO
Nov 17, 9:50 PM MSTSNOW 21 S Greeley, CO
Nov 17, 9:53 PM MSTSNOW 2.93 Wsw Fort Collins, COREPORT VIA TWITTER.
Nov 17, 10:05 PM MSTSNOW 6.33 Nw Boulder, CO.

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

The nearest sounding before it

Grand Junction, CO (KGJT), launched 12:00Z, 3.6 hours before the alert went out and 313 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, Grand Junction, CO at 12:00Z on 2022-11-17Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Grand Junction, CO at 12:00Z on 2022-11-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 128 square meters per square second.19395878Sfc1 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
1869 m above ground
0-6 km bulk shear
63 kt
0-1 km storm-relative helicity
128 m²/s²
0-3 km storm-relative helicity
198 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

017 
WWUS45 KBOU 171534
WSWBOU

URGENT - WINTER WEATHER MESSAGE
National Weather Service Denver CO
834 AM MST Thu Nov 17 2022

COZ038-180215-
/O.UPG.KBOU.WW.Y.0033.000000T0000Z-221118T1600Z/
/O.NEW.KBOU.WS.W.0009.221117T1534Z-221118T1600Z/
Larimer County Below 6000 Feet/Northwest Weld County-
Including the cities of Nunn, Hereford, Fort Collins, and
Loveland
834 AM MST Thu Nov 17 2022

...WINTER STORM WARNING IN EFFECT UNTIL 9 AM MST FRIDAY...

* WHAT...Heavy snow ongoing. Additional snow accumulations between 4 
  and 8 inches. Winds gusting as high as 35 mph.

* WHERE...Fort Collins.

* WHEN...Until 9 AM MST Friday.

* IMPACTS...Travel could be very difficult. The hazardous conditions 
  could impact the Thursday morning and evening commutes.

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.

&&

$$

COZ039-180215-
/O.UPG.KBOU.WW.Y.0033.221117T1900Z-221118T1600Z/
/O.NEW.KBOU.WS.W.0009.221117T1534Z-221118T1600Z/
Boulder And Jefferson Counties Below 6000 Feet/West Broomfield
County-
Including the cities of Longmont, Arvada, Golden, Boulder, and
Lakewood
834 AM MST Thu Nov 17 2022

...WINTER STORM WARNING IN EFFECT UNTIL 9 AM MST FRIDAY...

* WHAT...Heavy snow ongoing. Additional snow accumulations between 5 
  and 10 inches.

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

* WHEN...Until 9 AM MST Friday.

* IMPACTS...Travel could be very difficult. The hazardous conditions 
  could impact the Thursday morning and evening commutes.

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.

&&

$$

COZ036-040-041-045-180215-
/O.EXT.KBOU.WW.Y.0033.221117T1534Z-221118T1600Z/
Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet-North Douglas
County Below 6000 Feet/Denver/West Adams and Arapahoe
Counties/East Broomfield County-Elbert/Central and East Douglas
Counties Above 6000 Feet-Central and East Adams and Arapahoe
Counties-
Including the cities of City of Denver, Fondis, Idaho Springs,
Deer Trail, Brighton, Georgetown, Westcreek, Leader, Kiowa,
Central City, Byers, Bennett, Littleton, Evergreen, Denver
International Airport, Castle Rock, Bailey, Elbert, Highlands
Ranch, Aurora, Parker, and Larkspur
834 AM MST Thu Nov 17 2022

...WINTER WEATHER ADVISORY NOW IN EFFECT UNTIL 9 AM MST FRIDAY...

* WHAT...Snow ongoing. Total snow accumulations between 2 and 6 
  inches. Locally higher amounts possible.

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

* WHEN...Until 9 AM MST Friday.

* IMPACTS...Travel could be very difficult. The hazardous conditions 
  could impact the Thursday morning and evening commutes.

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.

&&

$$

COZ031-033-035-180215-
/O.CON.KBOU.WW.Y.0033.000000T0000Z-221118T1600Z/
West Jackson and West Grand Counties Above 9000 Feet-South and
East Jackson/Larimer/North and Northeast Grand/Northwest Boulder
Counties Above 9000 Feet-Larimer and Boulder Counties Between
6000 and 9000 Feet-
Including the cities of Rabbit Ears Range, Red Feather Lakes,
Nederland, Glendevey, Rocky Mountain National Park, Willow Creek
Pass, Mt Zirkel, Laramie and Medicine Bow Mountains, Estes Park,
and Cameron Pass
834 AM MST Thu Nov 17 2022

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 AM MST FRIDAY...

* WHAT...Snow ongoing. Total snow accumulations between 4 and 10 
  inches, with locally higher amounts possible in the mountains and 
  foothills of Larimer and Boulder Counties. Winds gusting as high 
  as 35 mph.

* WHERE...Rabbit Ears Pass, Rocky Mountain National Park and the 
  Medicine Bow Range, and The Northern Front Range Foothills.

* WHEN...Until 9 AM MST Friday.

* IMPACTS...Travel will be hazardous with slick and snowpacked roads.

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.

&&

$$

COZ043-180215-
/O.CON.KBOU.WW.Y.0033.000000T0000Z-221118T1600Z/
Central and South Weld County-
Including the cities of Fort Lupton, Eaton, Greeley, and Roggen
834 AM MST Thu Nov 17 2022

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 AM MST FRIDAY...

* WHAT...Snow ongoing. Total snow accumulations between 2 and 6 
  inches. Winds gusting as high as 25 mph.

* WHERE...Greeley.

* WHEN...Until 9 AM MST Friday.

* IMPACTS...Plan on slippery road conditions. The hazardous 
  conditions could impact the Thursday morning and evening commutes, 
  with lingering impacts possible Friday morning even as snow ends.

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.

&&

$$

COZ034-180215-
/O.CON.KBOU.WW.Y.0033.221117T1900Z-221118T1600Z/
South and Southeast Grand/West Central and Southwest
Boulder/Gilpin/Clear Creek/Summit/North and West Park Counties
Above 9000 Feet-
Including the cities of Berthoud Pass, Williams Fork Mountains,
Breckenridge, Mount Evans, Eisenhower Tunnel, Winter Park, East
Slopes Southern Gore Range, Kenosha Mountains, Indian Peaks, and
East Slopes Mosquito Range
834 AM MST Thu Nov 17 2022

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM NOON TODAY TO 9 AM 
MST FRIDAY...

* WHAT...Snow ongoing. Total snow accumulations between 3 and 8 
  inches, with lower amounts in Summit and Park Counties. Winds 
  gusting as high as 40 mph.

* WHERE...The Mountains of Summit County, the Mosquito Range, and 
  the Indian Peaks.

* WHEN...From Noon today to 9 AM MST Friday. Snow will become more 
  widespread tonight.

* IMPACTS...Travel will be hazardous with slick and snowpacked roads.

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

Danielson
4 follow-up statements
075 
WWUS45 KBOU 180244
WSWBOU

URGENT - WINTER WEATHER MESSAGE
National Weather Service Denver CO
744 PM MST Thu Nov 17 2022

COZ038-039-181600-
/O.CON.KBOU.WS.W.0009.000000T0000Z-221118T1600Z/
Larimer County Below 6000 Feet/Northwest Weld County-Boulder And
Jefferson Counties Below 6000 Feet/West Broomfield County-
Including the cities of Boulder, Nunn, Golden, Longmont,
Hereford, Arvada, Loveland, Lakewood, and Fort Collins
744 PM MST Thu Nov 17 2022

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 9 AM MST FRIDAY...

* WHAT...Heavy snow ongoing. Additional snow accumulations up to 5 
  inches, with the heaviest snow likely in Boulder county.

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

* WHEN...Until 9 AM MST Friday.

* IMPACTS...Travel could be very difficult. Snow covered roads will 
  make travel hazardous. The hazardous conditions could impact the 
  Friday 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.

&&

$$

COZ031-033-035-181600-
/O.CON.KBOU.WW.Y.0033.000000T0000Z-221118T1600Z/
West Jackson and West Grand Counties Above 9000 Feet-South and
East Jackson/Larimer/North and Northeast Grand/Northwest Boulder
Counties Above 9000 Feet-Larimer and Boulder Counties Between
6000 and 9000 Feet-
Including the cities of Glendevey, Rocky Mountain National Park,
Red Feather Lakes, Estes Park, Laramie and Medicine Bow
Mountains, Mt Zirkel, Willow Creek Pass, Rabbit Ears Range,
Nederland, and Cameron Pass
744 PM MST Thu Nov 17 2022

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 AM MST FRIDAY...

* WHAT...Snow ongoing. Additional snow accumulations between 1 and 4 
  inches.

* WHERE...Rabbit Ears Pass, Rocky Mountain National Park and the 
  Medicine Bow Range, and The Northern Front Range Foothills.

* WHEN...Until 9 AM MST Friday.

* IMPACTS...Travel will be hazardous with slick and snowpacked roads.

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.

&&

$$

COZ034-181600-
/O.CON.KBOU.WW.Y.0033.000000T0000Z-221118T1600Z/
South and Southeast Grand/West Central and Southwest
Boulder/Gilpin/Clear Creek/Summit/North and West Park Counties
Above 9000 Feet-
Including the cities of East Slopes Southern Gore Range, Winter
Park, Indian Peaks, Mount Evans, Williams Fork Mountains,
Breckenridge, Eisenhower Tunnel, East Slopes Mosquito Range,
Berthoud Pass, and Kenosha Mountains
744 PM MST Thu Nov 17 2022

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 AM MST FRIDAY...

* WHAT...Snow ongoing. Additional snow accumulations up to 5 inches.

* WHERE...The Mountains of Summit County, the Mosquito Range, and 
  the Indian Peaks.

* WHEN...Until 9 AM MST Friday.

* IMPACTS...Travel will be hazardous with slick and snowpacked roads.

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.

&&

$$

COZ036-040-041-045-181600-
/O.CON.KBOU.WW.Y.0033.000000T0000Z-221118T1600Z/
Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet-North Douglas
County Below 6000 Feet/Denver/West Adams and Arapahoe
Counties/East Broomfield County-Elbert/Central and East Douglas
Counties Above 6000 Feet-Central and East Adams and Arapahoe
Counties-
Including the cities of Castle Rock, Central City, Denver
International Airport, Georgetown, Parker, Larkspur, Littleton,
Aurora, Brighton, Evergreen, Westcreek, Byers, Fondis, Idaho
Springs, Bailey, Kiowa, Highlands Ranch, Elbert, Leader, City of
Denver, Deer Trail, and Bennett
744 PM MST Thu Nov 17 2022

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 AM MST FRIDAY...

* WHAT...Snow ongoing. Additional snow accumulations up to 4 inches.

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

* WHEN...Until 9 AM MST Friday.

* IMPACTS...Plan on slippery road conditions. The hazardous 
  conditions could impact the Friday 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.

&&

$$

COZ043-181600-
/O.CON.KBOU.WW.Y.0033.000000T0000Z-221118T1600Z/
Central and South Weld County-
Including the cities of Fort Lupton, Eaton, Roggen, and Greeley
744 PM MST Thu Nov 17 2022

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 AM MST FRIDAY...

* WHAT...Snow ongoing. Additional snow accumulations up to 2 inches.

* WHERE...Greeley.

* WHEN...Until 9 AM MST Friday.

* IMPACTS...Plan on slippery road conditions. The hazardous 
  conditions could impact the Friday 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

Hiris
871 
WWUS45 KBOU 180855
WSWBOU

URGENT - WINTER WEATHER MESSAGE
National Weather Service Denver CO
155 AM MST Fri Nov 18 2022

COZ038-181600-
/O.CAN.KBOU.WS.W.0009.000000T0000Z-221118T1600Z/
/O.EXA.KBOU.WW.Y.0033.000000T0000Z-221118T1600Z/
Larimer County Below 6000 Feet/Northwest Weld County-
Including the cities of Nunn, Hereford, Fort Collins, and
Loveland
155 AM MST Fri Nov 18 2022

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 9 AM MST THIS MORNING...
...WINTER STORM WARNING IS CANCELLED...

* WHAT...Snow diminishing to flurries and ending early this morning. 
  Additional snow accumulations up to one inch.

* WHERE...Fort Collins.

* WHEN...Until 9 AM MST this morning.

* IMPACTS...Plan on slippery road conditions. The hazardous 
  conditions will impact the Friday 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.

&&

$$

COZ039-181600-
/O.CON.KBOU.WS.W.0009.000000T0000Z-221118T1600Z/
Boulder And Jefferson Counties Below 6000 Feet/West Broomfield
County-
Including the cities of Golden, Longmont, Boulder, Arvada, and
Lakewood
155 AM MST Fri Nov 18 2022

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 9 AM MST THIS 
MORNING...

* WHAT...Snow ongoing. Additional snow accumulations up to two 
  inches.

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

* WHEN...Until 9 AM MST this morning.

* IMPACTS...Snow covered roads will make travel hazardous. The 
  hazardous conditions will impact the Friday 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.

&&

$$

COZ031-033-035-181600-
/O.CON.KBOU.WW.Y.0033.000000T0000Z-221118T1600Z/
West Jackson and West Grand Counties Above 9000 Feet-South and
East Jackson/Larimer/North and Northeast Grand/Northwest Boulder
Counties Above 9000 Feet-Larimer and Boulder Counties Between
6000 and 9000 Feet-
Including the cities of Estes Park, Rocky Mountain National Park,
Rabbit Ears Range, Laramie and Medicine Bow Mountains, Willow
Creek Pass, Glendevey, Mt Zirkel, Nederland, Red Feather Lakes,
and Cameron Pass
155 AM MST Fri Nov 18 2022

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 AM MST THIS 
MORNING...

* WHAT...Snow ongoing. Additional snow accumulations up to two 
  inches.

* WHERE...Rabbit Ears Pass, Rocky Mountain National Park and the 
  Medicine Bow Range, and The Northern Front Range Foothills.

* WHEN...Until 9 AM MST this morning.

* IMPACTS...Travel will be hazardous with slick and snowpacked roads.

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.

&&

$$

COZ034-181600-
/O.CON.KBOU.WW.Y.0033.000000T0000Z-221118T1600Z/
South and Southeast Grand/West Central and Southwest
Boulder/Gilpin/Clear Creek/Summit/North and West Park Counties
Above 9000 Feet-
Including the cities of Breckenridge, East Slopes Southern Gore
Range, Kenosha Mountains, East Slopes Mosquito Range, Indian
Peaks, Williams Fork Mountains, Winter Park, Berthoud Pass,
Eisenhower Tunnel, and Mount Evans
155 AM MST Fri Nov 18 2022

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 AM MST THIS 
MORNING...

* WHAT...Snow ongoing. Additional snow accumulations up to two 
  inches.

* WHERE...The Mountains of Summit County, the Mosquito Range, and 
  the Indian Peaks.

* WHEN...Until 9 AM MST this morning.

* IMPACTS...Travel will be hazardous with slick and snowpacked 
  roads. Chain laws may be enacted on I-70 and the approaches to the 
  Eisenhower/Johnson Tunnels and Vail Pass.

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.

&&

$$

COZ036-040-041-045-181600-
/O.CON.KBOU.WW.Y.0033.000000T0000Z-221118T1600Z/
Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet-North Douglas
County Below 6000 Feet/Denver/West Adams and Arapahoe
Counties/East Broomfield County-Elbert/Central and East Douglas
Counties Above 6000 Feet-Central and East Adams and Arapahoe
Counties-
Including the cities of Denver International Airport, Larkspur,
Aurora, Elbert, Evergreen, Georgetown, Highlands Ranch, Central
City, Bailey, Kiowa, Westcreek, City of Denver, Parker, Fondis,
Castle Rock, Deer Trail, Littleton, Brighton, Leader, Bennett,
Byers, and Idaho Springs
155 AM MST Fri Nov 18 2022

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 AM MST THIS 
MORNING...

* WHAT...Snow ongoing. Additional snow accumulations up to two 
  inches.

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

* WHEN...Until 9 AM MST this morning.

* IMPACTS...Plan on slick and hazardous road conditions. The 
  hazardous conditions will impact the Friday 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.

&&

$$

COZ043-181600-
/O.CON.KBOU.WW.Y.0033.000000T0000Z-221118T1600Z/
Central and South Weld County-
Including the cities of Fort Lupton, Eaton, Roggen, and Greeley
155 AM MST Fri Nov 18 2022

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 AM MST THIS 
MORNING...

* WHAT...Snow will taper off to flurries and end early this morning. 
  Additional snow accumulations less than one inch.

* WHERE...Greeley.

* WHEN...Until 9 AM MST this morning.

* IMPACTS...Plan on slippery road conditions. The hazardous 
  conditions will impact the Friday 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
110 
WWUS45 KBOU 181412
WSWBOU

URGENT - WINTER WEATHER MESSAGE
National Weather Service Denver CO
712 AM MST Fri Nov 18 2022

COZ031-033-035-038-043-045-181515-
/O.CAN.KBOU.WW.Y.0033.000000T0000Z-221118T1600Z/
West Jackson and West Grand Counties Above 9000 Feet-South and
East Jackson/Larimer/North and Northeast Grand/Northwest Boulder
Counties Above 9000 Feet-Larimer and Boulder Counties Between
6000 and 9000 Feet-Larimer County Below 6000 Feet/Northwest Weld
County-Central and South Weld County-Central and East Adams and
Arapahoe Counties-
Including the cities of Roggen, Nederland, Rabbit Ears Range,
Rocky Mountain National Park, Hereford, Red Feather Lakes, Estes
Park, Cameron Pass, Eaton, Bennett, Glendevey, Mt Zirkel,
Loveland, Byers, Nunn, Leader, Fort Collins, Greeley, Willow
Creek Pass, Laramie and Medicine Bow Mountains, Deer Trail, and
Fort Lupton
712 AM MST Fri Nov 18 2022

...WINTER WEATHER ADVISORY IS CANCELLED...

The threat has ended.

$$

COZ039-181600-
/O.CON.KBOU.WS.W.0009.000000T0000Z-221118T1600Z/
Boulder And Jefferson Counties Below 6000 Feet/West Broomfield
County-
Including the cities of Boulder, Golden, Arvada, Longmont, and
Lakewood
712 AM MST Fri Nov 18 2022

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 9 AM MST THIS 
MORNING...

* WHAT...Snow ongoing. Minimal additional snow accumulations.

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

* WHEN...Until 9 AM MST this morning.

* IMPACTS...Roads are slick and hazardous. Snow covered roads will 
  make travel hazardous.

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.

&&

$$

COZ034-181600-
/O.CON.KBOU.WW.Y.0033.000000T0000Z-221118T1600Z/
South and Southeast Grand/West Central and Southwest
Boulder/Gilpin/Clear Creek/Summit/North and West Park Counties
Above 9000 Feet-
Including the cities of Winter Park, Mount Evans, East Slopes
Mosquito Range, Kenosha Mountains, Eisenhower Tunnel, Indian
Peaks, Breckenridge, East Slopes Southern Gore Range, Williams
Fork Mountains, and Berthoud Pass
712 AM MST Fri Nov 18 2022

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 AM MST THIS 
MORNING...

* WHAT...Snow ongoing. Minimal additional snow accumulations.

* WHERE...The Mountains of Summit County, the Mosquito Range, and 
  the Indian Peaks.

* WHEN...Until 9 AM MST this morning.

* IMPACTS...Plan on slippery road conditions. The hazardous 
  conditions will impact the Friday 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.

&&

$$

COZ036-040-041-181600-
/O.CON.KBOU.WW.Y.0033.000000T0000Z-221118T1600Z/
Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet-North Douglas
County Below 6000 Feet/Denver/West Adams and Arapahoe
Counties/East Broomfield County-Elbert/Central and East Douglas
Counties Above 6000 Feet-
Including the cities of Idaho Springs, Central City, Westcreek,
Aurora, Castle Rock, City of Denver, Fondis, Evergreen, Highlands
Ranch, Littleton, Denver International Airport, Larkspur, Parker,
Elbert, Brighton, Georgetown, Bailey, and Kiowa
712 AM MST Fri Nov 18 2022

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 AM MST THIS 
MORNING...

* WHAT...Snow ongoing. Minimal additional snow accumulations.

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

* WHEN...Until 9 AM MST this morning.

* IMPACTS...Plan on slippery road conditions. The hazardous 
  conditions will impact the Friday 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

Danielson
586 
WWUS45 KBOU 181550
WSWBOU

URGENT - WINTER WEATHER MESSAGE
National Weather Service Denver CO
850 AM MST Fri Nov 18 2022

COZ039-181700-
/O.EXP.KBOU.WS.W.0009.000000T0000Z-221118T1600Z/
Boulder And Jefferson Counties Below 6000 Feet/West Broomfield
County-
Including the cities of Boulder, Golden, Arvada, Longmont, and
Lakewood
850 AM MST Fri Nov 18 2022

...WINTER STORM WARNING WILL EXPIRE AT 9 AM MST THIS MORNING...

The snow has stopped and dry conditions will continue the rest of 
the day. Some roads will still be snow covered and slick through 
much of the day.

$$

COZ034-036-040-041-181700-
/O.EXP.KBOU.WW.Y.0033.000000T0000Z-221118T1600Z/
South and Southeast Grand/West Central and Southwest
Boulder/Gilpin/Clear Creek/Summit/North and West Park Counties
Above 9000 Feet-Jefferson and West Douglas Counties Above
6000 Feet/Gilpin/Clear Creek/Northeast Park Counties Below
9000 Feet-North Douglas County Below 6000 Feet/Denver/West Adams
and Arapahoe Counties/East Broomfield County-Elbert/Central and
East Douglas Counties Above 6000 Feet-
Including the cities of Westcreek, Fondis, Highlands Ranch,
Littleton, Brighton, Parker, Bailey, Berthoud Pass, Winter Park,
Elbert, East Slopes Mosquito Range, Central City, Aurora, City of
Denver, Evergreen, Denver International Airport, East Slopes
Southern Gore Range, Larkspur, Mount Evans, Kenosha Mountains,
Breckenridge, Kiowa, Idaho Springs, Castle Rock, Eisenhower
Tunnel, Indian Peaks, Williams Fork Mountains, and Georgetown
850 AM MST Fri Nov 18 2022

...WINTER WEATHER ADVISORY WILL EXPIRE AT 9 AM MST THIS MORNING...

The snow has stopped and dry conditions will continue the rest of 
the day. Some roads will still be snow covered and slick through 
much of the day.

$$

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

Danielson

What forecasters said that day

The local office's own words before this winter storm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Denver/Boulder, CO wrote its last area forecast discussion before this winter storm warning went out at Nov 17, 4:03 AM MST, 4 hours 31 minutes earlier.

Area forecast discussion, Nov 17, 4:03 AM MST, 4 hours 31 minutes before
Area Forecast Discussion
National Weather Service Denver/Boulder CO
403 AM MST Thu Nov 17 2022

.SHORT TERM...(Today and tonight)
Issued at 400 AM MST Thu Nov 17 2022

...WINTER RETURNS IN FULL FORCE...

Surface analysis shows the leading edge of arctic air pushing
across the northern plains in these early morning hours, and that
will overtake the rest of the plains by/shortly after daybreak.
Temperatures were in the lower to mid 20s behind the front, and
that's about all we'll do today for highs as constant cold
advection occurs throughout the day. In fact, by about 5 pm most
locations should have dropped into the upper teens. Lows tonight
will drop into the single digits, with below zero readings in the
mountains and foothills.

Now for the snow and travel impacts...

Current observations show light snow and flurries falling over
eastern Wyoming behind the arctic front. We'll see the same
situation across our plains and foothills this morning with
enough low level moisture, upslope, and weak dynamics. While most
of this will remain on the light side, a couple briefly moderate
bands will be possible as mid level frontogenesis begins to
strengthen. The main threat for those bands would be over the
northern tier of Colorado Counties where the Winter Weather
Advisory starts early this morning. Denver will likely see some
light snow as well for at least the latter half of the morning
commute, but this snow should remain on the lighter side being
farther away from the synoptic support and deeper moisture.

The forecast for this afternoon is a little tricky, as most models
show a little respite in the snow about mid day, before snow ticks
up again late in the afternoon and evening. It's not uncommon to
get a mid day lull in the lack of forcing, but again the northern
border area remains under strong forcing and mid level
frontogenesis. The passage of the upper jet max to our northeast
means we'll also be getting into the right rear entrance region.
Cross sections show persistent ageostrophic ascent associated with
the F-gen, so we think at least the northern tier of counties
will remain in healthier snowfall through the afternoon. It's not
so clear cut in Denver with the possible diurnal wane, but with
the improved forcing late this afternoon we would expect an
increase in snowfall rates despite some of the latest mesoscale
model data. This increase would occur by early evening at the
latest, so we are still concerned with the evening commute across
Denver. Travel conditions will be deteriorating so we'll continue
to message that accordingly. One interesting note is if we see
enough solar insolation we could actually get a little melting
initially which would NOT be in our best interest for impacts. If
that occurs and then we get a quick increase in snow in the
evening commute it could be quite the difficult drive with a quick
freeze/ice compaction. Current forecast road temps get us right
up to the freezing mark around Denver, so it could be close. A
better scenario would be for just light snow and roads to remain
cold enough for a "middle of the winter" type snow covered road
situation and limited ice formation.

Otherwise, there's not much change in the overall guidance and
expected storm total forecast. QPF numbers have shown their
typical random gyrations, but overall SREF plumes remain constant
with amounts around 0.20 inches liquid in Denver and around 0.35
inches closer to Boulder and Fort Collins. With favorable
moisture and temperature profiles for dendritic crystal growth
through a relatively deep layer, we're still looking for high SLRs
close to 20:1 especially as we get into the deeper lift that
slowly edges southward across the forecast area through tonight.
We still expect locally heavy bands as well with the noted forcing
mechanisms, and even hints of Conditional Symmetric Instability
(CSI). Our forecast totals remain generally the same, with 2-6
inches across most of the I-25 Corridor, and 4-10 inches in/near
the foothills with Boulder and Larimer Counties under the gun for
the heavier totals. Lower amounts can be expected on the eastern
plains with a dusting to 3 inches. Summit county remains on the
edge of any orographic and dynamically forced precipitation
through this evening. Not until overnight tonight will that area
fill in entirely, so totals over most of this area will likely be
on the low end of Advisory Criteria. Locations like Berthoud Pass
and points north will have significantly more snowfall. Even the
southern Front Range Foothills south of about Conifer and the
Palmer Divide could be shorted on snow totals per some of the
latest model guidance, but in these types of cases the best
frontogentical band usually ends up slipping farther south than
forecast so those areas should still receive a few inches of snow
and have travel impacts that last through the Friday morning rush
hour. All Winter Weather Advisories remain unchanged at this
point.

.LONG TERM...(Friday through Wednesday)
Issued at 305 AM MST Thu Nov 17 2022

I did not make significant changes to the forecast in this
package. Model solutions have been pretty consistent through the
weekend and WPC cluster analysis of ensemble forecast systems
suggests good confidence in these solutions through early next
week. Around Tuesday, solutions start to diverge significantly. It
still looks like the next chance of snowfall is Wednesday, but
probably just light snowfall mostly confined to the high country.

Friday morning, light snowfall will persist mainly in the
southern mountains and foothills, Palmer Divide and adjacent
plains including much of the urban corridor and specifically
Denver metro area. There will likely be minor impacts to the
morning rush hour, and our Winter Weather Advisory will remain in
effect through 9 AM. As the trough axis moves overhead, synoptic
ascent will turn to subsidence and gradual clearing will begin
from north to south. Snowfall should diminish by noon. Total snow
accumulations from this system will generally range from 2 to 6
inches across the I-25 Corridor, 4 to 10 inches in the mountains
and foothills north of I-70 (favoring Boulder and Larimer
Counties), and trace to 3 inches over the eastern plains. Skies
should remain mostly cloudy through the day with fresh snow cover
and light northerly cold air advection, which will keep
temperatures very cold Friday. Expect highs in the 20s across the
plains and mostly single digits and teens across the high country,
which is 20 to 30 degrees below normal for most areas. Skies
should then be mostly clear overnight, and low temperatures are
forecast to fall into the single digits across the plains and
negative single digits across the high country. It will likely
become extremely cold in the typical cold pockets where strong
inversions will form.

Over the weekend, there will be a decreasing and more northerly
flow aloft behind the trough. Under mostly clear skies, a warming
trend will bring temperatures back to near-normal by Sunday,
though they may remain a bit colder where snow cover remains and
winds are lighter. Early next week, mostly clear and near-normal
conditions should persist with a more zonal flow aloft.

By Tuesday, model solutions start to diverge significantly so
there is less confidence in forecast details through mid-week.
However, no models show any strong, organized features approaching
northeast Colorado, they instead disagree on the particulars of a
rather disorganized synoptic pattern which doesn't look very
threatening. We'll continue to carry slightly cool temperatures
and a chance of light snowfall in the mountains on Wednesday. A
stronger trough with proper placement could bring cooler
conditions and maybe even some light snowfall to the lower
elevations. A stronger ridge could mean mostly clear skies and
near-normal temperatures persist through mid-week. It's too early
to tell.

&&

.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 400 AM MST Thu Nov 17 2022

Arctic cold front should push through KDEN by 12Z-13Z, with lower
MVFR clouds and visibility as light snow/flurries develop shortly
behind it. Front will be about 30-60 minutes behind that at KBJC
and KAPA, respectively. Could see some north/northeast gusts to
around 25 knots with the frontal passage, before relaxing to
around 10 knots through the rest of the period from the
east/northeast. Snow intensity is expected to increase in the
immediate Denver area TAF sites 22Z-01Z, with visibility dropping
closer to 1SM and potential for locally heavier bands with lower
visibility. Total snow accumulations by the time snow winds down
early Friday morning are most likely to range between 2 and 5
inches at KDEN and KAPA, and 4 to 6 inches at KBJC.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 9 AM MST Friday for COZ031-033-035-
038-043.

Winter Weather Advisory from noon today to 9 AM MST Friday for
COZ034-036-039>041-045.

&&

SHORT TERM...Barjenbruch
LONG TERM...EJD
AVIATION...Barjenbruch
Hazardous weather outlook, Nov 17, 4:09 AM MST, 4 hours 25 minutes before
Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
409 AM MST Thu Nov 17 2022

COZ030>051-181115-
Jackson County Below 9000 Feet-
West Jackson and West Grand Counties Above 9000 Feet-
Grand and Summit Counties Below 9000 Feet-
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-
Central and Southeast Park County-
Larimer County Below 6000 Feet/Northwest Weld County-
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-
Elbert/Central and East Douglas Counties Above 6000 Feet-
Northeast Weld County-Central and South Weld County-Morgan County-
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-
Logan County-Washington County-Sedgwick County-Phillips County-
409 AM MST Thu Nov 17 2022

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 AM MST
FRIDAY FOR THE NORTHERN MOUNTAINS, FOOTHILLS, I-25 CORRIDOR, AND
ADJACENT PLAINS...

This hazardous weather outlook is for northeast and north central
Colorado.

.DAY ONE...Today and Tonight

Travel will be hazardous and slow due to developing slick and
snowpacked roads. A few slick spots will be possible this morning,
but the afternoon and evening commutes will be more heavily
impacted. Hazardous travel conditions will persist overnight.

Light snow and flurries will develop over most of the northern
mountains, plains, and foothills this morning. Snow intensity will
increase through the day across the northern tier of Colorado
Counties, including locations like Estes Park, Fort Collins, and
Greeley. This more persistent and heavier snow will then gradually
shift southward across the forecast area late this afternoon
through tonight.

It will also be very cold as an arctic airmass overspread the
region. Temperatures today will hold in the lower to mid 20s in
most areas. Lows tonight will drop into the single digits, with
some below zero readings in the mountains and foothills. Break out
the winter parkas, mittens, and hats to protect yourself from the
cold.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

Friday morning, light snowfall will persist mainly in the
southern mountains and foothills, Palmer Divide and adjacent
plains including much of the urban corridor and specifically
Denver metro area. There will likely be impacts to the morning
rush hour. Total snow accumulations from this system will
generally range from 2 to 6 inches across the I-25 Corridor, 4 to
10 inches in and near the mountains and foothills north of I-70
(favoring Boulder and Larimer Counties), and trace to 3 inches
over the eastern plains.

Very cold temperatures will persist Friday as well, with highs
only in the 20s across the plains and single digits and teens in
the high country, which is 20 to 30 degrees below normal in most
areas.

This system will clear out Friday and there will be a warming
trend through the weekend. It still looks like the next chance of
snowfall is Wednesday, but probably just light snowfall mostly
confined to the high country.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today or tonight.

Nearby

Winter Storm Warnings in Colorado, 2022Every winter storm warning in 2022

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.