Alert archive / Colorado / Winter Storm Warnings in 2021
Winter Storm Warning 1, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this winter storm warning at Feb 3, 2021, 3:27 PM MST for 7 counties in Colorado. It was in force for 17 hr. 25 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 3, 2021, 3:27 PM MST (22:27 UTC)
- Expired
- Feb 4, 2021, 8:00 AM MST
- In force
- 17 hr
- Issued by
- NWS Denver/Boulder, CO
Counties Boulder County, CO, Clear Creek County, CO, Gilpin County, CO, Grand County, CO, Jefferson County, CO, Park County, CO, Summit County, CO
The radar
The Denver radar (KFTG), 97 km from the middle of the area, began a volume at 22:29 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 |
|---|---|---|---|
| Feb 4, 4:39 AM MST | SNOW 1.5 | 3 S Brainard Lake, CO | UNIVERSITY CAMP SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | SNOW 1.5 | 8 Sse Cameron Pass, CO | PHANTOM VALLEY SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | SNOW 3 | 1 Ne Echo Lake, CO | ECHO LAKE SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | SNOW 3 | 3 Sw Meeker Park, CO | COPELAND LAKE SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | SNOW 3 | 9 Se Weston Pass, CO | ROUGH AND TUMBLE SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | SNOW 4.5 | 11 S Rabbit Ears Pass, CO | BUFFALO PARK SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | SNOW 4.5 | 1 Sse Loveland Pass, CO | GRIZZLY PEAK SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | SNOW 4.5 | 1 Sw Eldora, CO | LAKE ELDORA SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | SNOW 4.5 | 1 Wnw Loveland Pass, CO | LOVELAND BASIN SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | SNOW 4.5 | 3 Sw Ward, CO | NIWOT SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | SNOW 4.5 | 9 Sse Spicer, CO | ARAPAHO RIDGE SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | HEAVY SNOW 6 | 3 Nne Mount Audubon, CO | SAWTOOTH SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | HEAVY SNOW 6 | 3 Wnw Alma, CO | BUCKSKIN JOE SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | HEAVY SNOW 6 | 4 S Longs Peak, CO | WILD BASIN SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | HEAVY SNOW 6 | 5 Wsw Guanella Pass, CO | JACKWHACKER GULCH SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | HEAVY SNOW 6 | 7 Sse Cameron Pass, CO | LAKE IRENE SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | HEAVY SNOW 6 | 8 Sse Rand, CO | WILLOW CREEK PASS SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | HEAVY SNOW 7.5 | 7 E Blue River, CO | MICHIGAN CREEK SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | HEAVY SNOW 9 | 5 W Berthoud Falls, CO | JONES PASS SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | HEAVY SNOW 9 | 6 Nw Silverthorne, CO | SUMMIT RANCH SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | HEAVY SNOW 10.5 | 5 W Green Mountain Rese, CO | ELLIOT RIDGE SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | HEAVY SNOW 12 | 1 W Copper Mountain, CO | COPPER MOUNTAIN SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | HEAVY SNOW 12 | 5 Ssw Blue River, CO | HOOSIER PASS SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | HEAVY SNOW 12 | 5 Wsw Winter Park, CO | FOOL CREEK SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
| Feb 4, 4:39 AM MST | HEAVY SNOW 15 | 10 Nne Silverthorne, CO | MIDDLE FORK CAMP SNOTEL SNOWFALL BETWEEN 5 AM 02/03/2021 AND 2 AM 02/04/2021 ESTIMATED USING A 15.0 TO 1 SNOW-TO-LIQUID RATIO |
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, 10.5 hours before the alert went out and 209 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2429 m above ground
- 0-6 km bulk shear
- 72 kt
- 0-1 km storm-relative helicity
- -27 m²/s²
- 0-3 km storm-relative helicity
- 178 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
408 WWUS45 KBOU 032227 WSWBOU URGENT - WINTER WEATHER MESSAGE National Weather Service Denver CO 327 PM MST Wed Feb 3 2021 ...SNOW AND BLOWING SNOW FOR THE MOUNTAINS TODAY AND TONIGHT... .A storm system will continue to move across Colorado this afternoon and evening with strong winds and increasing snow across the mountains during the day. The heaviest snow is expected to develop late this afternoon and evening as a cold front sweeps across the area. This will likely be accompanied by strong and gusty winds, creating a period of poor visibility and difficult travel conditions in the Colorado high country. Conditions are then expected to slowly improve late Wednesday night into Thursday morning as snow and winds decrease. COZ034-040630- /O.UPG.KBOU.WW.Y.0005.000000T0000Z-210204T1600Z/ /O.NEW.KBOU.WS.W.0001.210203T2227Z-210204T1500Z/ 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 Indian Peaks, Eisenhower Tunnel, East Slopes Southern Gore Range, Mount Evans, East Slopes Mosquito Range, Breckenridge, Winter Park, Williams Fork Mountains, Kenosha Mountains, and Berthoud Pass 327 PM MST Wed Feb 3 2021 ...WINTER STORM WARNING IN EFFECT UNTIL 8 AM MST THURSDAY... * WHAT...Snow and blowing snow expected. The snow may be heavy at times this afternoon and evening, with total snow accumulations of 6 to 14 inches. Winds gusting up to 60 mph. Snowfall rates may approach 2 inches per hour in the heavier snow, especially along the I-70 corridor through the mountains. * WHERE...The Mountains of Summit County, the Mosquito Range, and the Indian Peaks. * WHEN...Until 8 AM MST Thursday. * IMPACTS...Travel could be very difficult. The hazardous conditions could impact the Wednesday evening and Thursday morning commutes. Roads, and especially bridges and overpasses, will likely become slick and hazardous. Visibilities may drop below 1/4 mile due to falling and blowing snow. 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 the state you are calling from can be obtained by calling 5 1 1. && $$ COZ031-033-040630- /O.CON.KBOU.WW.Y.0005.000000T0000Z-210204T1600Z/ West Jackson and West Grand Counties Above 9000 Feet-South and East Jackson/Larimer/North and Northeast Grand/Northwest Boulder Counties Above 9000 Feet- Including the cities of Rocky Mountain National Park, Mt Zirkel, Laramie and Medicine Bow Mountains, Cameron Pass, Willow Creek Pass, and Rabbit Ears Range 327 PM MST Wed Feb 3 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 AM MST THURSDAY... * WHAT...Snow and blowing snow expected. The snow may be heavy at times late Wednesday afternoon and evening, with total snow accumulations of 6 to 12 inches. Winds gusting up to 60 mph. * WHERE...Rabbit Ears Pass, and Rocky Mountain National Park and the Medicine Bow Range. * WHEN...Until 9 AM MST Thursday. * IMPACTS...Plan on slippery road conditions. The hazardous conditions could impact the Wednesday evening and Thursday morning commutes. Roads, and especially bridges and overpasses, will likely become slick and hazardous. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ For more information from the National Weather Service, visit https://weather.gov/bou Entrekin
3 follow-up statements
930 WWUS45 KBOU 040251 WSWBOU URGENT - WINTER WEATHER MESSAGE National Weather Service Denver CO 751 PM MST Wed Feb 3 2021 ...SNOW AND BLOWING SNOW FOR THE MOUNTAINS TONIGHT... .A storm system will continue to move southward across Colorado tonight with strong winds and snow across the mountains. The snow will gradually taper off towards morning. A mix of rain and snow showers will turn to all snow across the plains towards midnight. COZ034-041100- /O.CON.KBOU.WS.W.0001.000000T0000Z-210204T1500Z/ 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 Indian Peaks, Eisenhower Tunnel, East Slopes Southern Gore Range, Mount Evans, East Slopes Mosquito Range, Breckenridge, Winter Park, Williams Fork Mountains, Kenosha Mountains, and Berthoud Pass 751 PM MST Wed Feb 3 2021 ...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 8 AM MST THURSDAY... * WHAT...Snow and blowing snow expected. The snow may be heavy at times this evening, with total snow accumulations of 6 to 14 inches. Winds gusting up to 50 mph. Snowfall rates may approach 1 inch per hour in the heavier snow. * WHERE...The Mountains of Summit County, the Mosquito Range, and the Indian Peaks. * WHEN...Until 8 AM MST Thursday. * IMPACTS...Plan on slippery road conditions with icy and snow packed roads. The hazardous conditions could impact the Thursday morning commute. Visibilities may drop below 1/4 mile due to falling and blowing snow. 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 the state you are calling from can be obtained by calling 5 1 1. && $$ COZ031-033-041100- /O.CON.KBOU.WW.Y.0005.000000T0000Z-210204T1600Z/ West Jackson and West Grand Counties Above 9000 Feet-South and East Jackson/Larimer/North and Northeast Grand/Northwest Boulder Counties Above 9000 Feet- Including the cities of Rocky Mountain National Park, Mt Zirkel, Laramie and Medicine Bow Mountains, Cameron Pass, Willow Creek Pass, and Rabbit Ears Range 751 PM MST Wed Feb 3 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 AM MST THURSDAY... * WHAT...Snow and blowing snow expected. The snow may be heavy at times this evening, with total snow accumulations of 6 to 12 inches. Winds gusting up to 50 mph. * WHERE...Rabbit Ears Pass, and Rocky Mountain National Park and the Medicine Bow Range. * WHEN...Until 9 AM MST Thursday. * IMPACTS...Plan on slippery road conditions. The hazardous conditions could impact the Thursday morning commute. Roads, and especially bridges and overpasses, will likely become slick and hazardous. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ For more information from the National Weather Service, visit https://weather.gov/bou Entrekin
559 WWUS45 KBOU 041030 WSWBOU URGENT - WINTER WEATHER MESSAGE National Weather Service Denver CO 330 AM MST Thu Feb 4 2021 COZ031-041830- /O.NEW.KBOU.WS.W.0002.210205T0000Z-210206T1200Z/ /O.CON.KBOU.WW.Y.0005.000000T0000Z-210204T1600Z/ West Jackson and West Grand Counties Above 9000 Feet- Including the cities of Mt Zirkel 330 AM MST Thu Feb 4 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 AM MST THIS MORNING... ...WINTER STORM WARNING IN EFFECT FROM 5 PM THIS AFTERNOON TO 5 AM MST SATURDAY... * WHAT...Snow and blowing snow decreasing this morning. The snow and wind will increase again tonight and continue through Friday night. The snow may be heavy at times on Friday. Total new snow accumulations of 10 to 18 inches by late Friday night. Winds gusting up to 50 mph. * WHERE...Rabbit Ears Pass. * WHEN...For the Winter Storm Warning, from 5 PM this afternoon to 5 AM MST Saturday. For the Winter Weather Advisory, until 9 AM MST this morning. * IMPACTS...Travel could be very difficult late tonight through Friday night. Visibilities may drop below 1/4 mile due to falling and blowing snow. 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 the state you are calling from can be obtained by calling 5 1 1. Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ COZ034-041500- /O.CON.KBOU.WS.W.0001.000000T0000Z-210204T1500Z/ South and Southeast Grand/West Central and Southwest Boulder/Gilpin/Clear Creek/Summit/North and West Park Counties Above 9000 Feet- Including the cities of Indian Peaks, Eisenhower Tunnel, East Slopes Southern Gore Range, Mount Evans, East Slopes Mosquito Range, Breckenridge, Winter Park, Williams Fork Mountains, Kenosha Mountains, and Berthoud Pass 330 AM MST Thu Feb 4 2021 ...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 8 AM MST THIS MORNING... * WHAT...Snow and blowing snow decreasing this morning. Additional snow accumulations of 1 to 2 inches. * WHERE...The Mountains of Summit County, the Mosquito Range, and the Indian Peaks. * WHEN...Until 8 AM MST this morning. * IMPACTS...Plan on slippery road conditions. The hazardous conditions could impact this mornings commute. PRECAUTIONARY/PREPAREDNESS ACTIONS... If you must travel, keep an extra flashlight, food, and water in your vehicle in case of an emergency. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ COZ033-041600- /O.CON.KBOU.WW.Y.0005.000000T0000Z-210204T1600Z/ South and East Jackson/Larimer/North and Northeast Grand/Northwest Boulder Counties Above 9000 Feet- Including the cities of Laramie and Medicine Bow Mountains, Rabbit Ears Range, Cameron Pass, Rocky Mountain National Park, and Willow Creek Pass 330 AM MST Thu Feb 4 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 AM MST THIS MORNING... * WHAT...Snow and blowing snow decreasing this morning. Additional accumulations of 1 to 2 inches. Winds gusting up to 50 mph. * WHERE...Rocky Mountain National Park and the Medicine Bow Range. * WHEN...Until 9 AM MST this morning. * IMPACTS...Plan on slippery road conditions. The hazardous conditions could impact this mornings commute. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ For more information from the National Weather Service, visit https://weather.gov/bou RPK
183 WWUS45 KBOU 041458 WSWBOU URGENT - WINTER WEATHER MESSAGE National Weather Service Denver CO 758 AM MST Thu Feb 4 2021 COZ034-041600- /O.EXP.KBOU.WS.W.0001.000000T0000Z-210204T1500Z/ South and Southeast Grand/West Central and Southwest Boulder/Gilpin/Clear Creek/Summit/North and West Park Counties Above 9000 Feet- Including the cities of Indian Peaks, Eisenhower Tunnel, East Slopes Southern Gore Range, Mount Evans, East Slopes Mosquito Range, Breckenridge, Winter Park, Williams Fork Mountains, Kenosha Mountains, and Berthoud Pass 758 AM MST Thu Feb 4 2021 ...WINTER STORM WARNING WILL EXPIRE AT 8 AM MST THIS MORNING... Road conditions should generally improve during the day, though exposed higher areas will continue to have areas of blowing and drifting snow. $$ COZ031-042300- /O.CAN.KBOU.WW.Y.0005.000000T0000Z-210204T1600Z/ /O.CON.KBOU.WS.W.0002.210205T0000Z-210206T1200Z/ West Jackson and West Grand Counties Above 9000 Feet- Including the cities of Mt Zirkel 758 AM MST Thu Feb 4 2021 ...WINTER STORM WARNING REMAINS IN EFFECT FROM 5 PM THIS AFTERNOON TO 5 AM MST SATURDAY... ...WINTER WEATHER ADVISORY IS CANCELLED... * WHAT...Only light snow is expected today. The snow and wind will increase again tonight and continue through Friday night. The snow may be heavy at times on Friday. Total new snow accumulations of 10 to 18 inches are expected by late Friday night, with winds gusting up to 50 mph. * WHERE...Rabbit Ears Pass. * WHEN...From 5 PM this afternoon to 5 AM MST Saturday. * IMPACTS...Travel could be very difficult to impossible on Friday and Friday night. Visibilities may drop below 1/4 mile due to falling and blowing snow. PRECAUTIONARY/PREPAREDNESS ACTIONS... Consider traveling over Rabbit Ears Pass today while conditions are better, or taking alternate routes. If you must travel during the storm, bring an extra flashlight, food, and water in your vehicle in case of an emergency. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ COZ033-041600- /O.CAN.KBOU.WW.Y.0005.000000T0000Z-210204T1600Z/ South and East Jackson/Larimer/North and Northeast Grand/Northwest Boulder Counties Above 9000 Feet- Including the cities of Laramie and Medicine Bow Mountains, Rabbit Ears Range, Cameron Pass, Rocky Mountain National Park, and Willow Creek Pass 758 AM MST Thu Feb 4 2021 ...WINTER WEATHER ADVISORY IS CANCELLED... Any snow today will be very light, though there will still be areas of blowing and drifting snow in exposed higher areas. Road conditions should generally improve during the day. $$ For more information from the National Weather Service, visit https://weather.gov/bou Gimmestad
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.