A fast moving upper level storm system, along with a deep low pressure system over Nebraska and high pressure building over Utah, combined to create a powerful windstorm across Northeast and North Central Colorado. In the mountains and foothills, several locations recorded wind gusts in excess of 100 mph.
Every event with a place to put it; 17 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS BOU wrote it up.
A fast moving upper level storm system, along with a deep low pressure system over Nebraska and high pressure building over Utah, combined to create a powerful windstorm across Northeast and North Central Colorado. In the mountains and foothills, several locations recorded wind gusts in excess of 100 mph. Numerous trees were knocked down throughout Arapahoe National Forest. One man was killed when he was impaled by a falling tree limb while driving along U.S. Highway 36, north of Boulder. High winds blew several vehicles off Interstate 76 near Sterling, forcing the closure of the interstate to high profile vehicles. One driver was injured when his semi trailer was blown off the interstate and rolled onto its side. Visibilities over the northeast corner of the state were also reduced significantly by a combination of blowing dust and blowing snow. The high winds also forced the closure of Interstate 25 at the Wyoming border. Downed power lines also sparked several small grassfires. The strong winds produced extensive damage to fences and some roofs, and also knocked down trees resulting in power outages to approximately 19,000 residents. In Fort Collins, a large light pole in Hughes Stadium at Colorado State University, crashed onto the upper press box level and slid into the stadium seating area. The pole damaged the roof and a fire sprinkler pole.
In the North Central Mountains and Front Range Foothills, peak wind gusts included: 126 mph, 7 miles south of Frisco; 111 mph, 3 miles south-southeast of Pinecliffe; 101 mph, 1 mile west of Lyons; 94 mph atop Berthoud Pass; 90 mph, 9 miles east of Dillon; 86 mph, 7 miles south-southwest of Frisco and 3 miles south of Golden; 84 mph, 4 miles northwest of Boulder; 81 mph in Boulder; 80 mph, 9 miles south of Fraser and 11 miles north of Kremmling; 79 mph at Kenosha Pass, NCAR Mesa Lab and the junction of U.S. Highways 72 and 93; 77 mph at Fairplay and National Wind Technology Center; 76 mph, 3 miles north-northwest of Morrison.
Peak wind gusts for the rest of the Urban Corridor and Northeast Plains of Colorado included: 80 mph, 4 miles east-northeast of Eaton, 3 mile east of Cedar Point; 79 mph, 3 miles north-northwest of Cornish; 77 mph, 2 miles north-northwest of New Raymer; 75 mph at Akron and north Longmont; 74 mph at Limon and 10 miles northeast of Pawnee Buttes; 73 mph, 4 miles east of Loveland, Sterling Airport and Woodrow; 72 mph at Briggsdale; 71 mph at the Natural Fort Rest Area; 70 mph at Haxtun, 7 miles north of Rockport and Sterling; 67 mph at Greeley Airport and 3 miles northeast of Loveland, 10 miles east of Parker and 5 miles northwest of Woodlin School; 65 mph at Crook; 64 mph at Buckley AFB and Lakewood; 63 mph, at Eaton, 4 miles east of Fort Collins, Holyoke, 4 miles east-northeast of Severance and Wellington; 62 mph, 6 miles east of Berthoud; 61 mph at Wiggins; 60 mph at Bennett and Front Range Airport in Watkins; 59 mph at Denver International Airport and Deer Trail; 58 mph, 2 miles west of Keenesburg, Rocky Mountain Regional Airport in Broomfield and 2 miles north-northwest of Louisville; 57 mph in Fort Collins.
The local office's own words before the first event, 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 the first event at Dec 30, 9:20 PM MST, 2 hours 40 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER CO 920 PM MST FRI DEC 30 2011 .UPDATE...THE WATER VAPOR PICTURES ARE STILL SHOWING STRONG DOWNWARD MOTION ON THE BACK SIDE OF THE INCOMING UPPER TROUGH. THE TROUGH AXIS IS OVER NORTH CENTRAL UTAH AND MOVING THIS WAY AT ABOUT 50 KNOTS. THE 00Z MODEL DATA IS STILL SHOWING STRONG WINDS FOR MUCH OF THE CWA SO WILL LET ALL THE HIGHLIGHTS AS IS. && .AVIATION...CAN NOT ARGUE WITH CURRENT TIMING OF STRONG WINDS IN THE TAF FOR DIA. WITH THE 06Z TAFS...WILL MAKE MINOR ADJUSTMENTS ONLY. && .PREV DISCUSSION... /ISSUED 315 PM MST FRI DEC 30 2011/ SHORT TERM...MODELS CONTINUE TO SHOW THE BORA WIND EVENT FOR TOMORROW. A 130 KT JET DIGGING DOWN ON THE BACK SIDE OF AN UPPER TROUGH...MODERATE TO STRONG (THE STRONGEST WE HAVE SEEN IN QUITE SOME TIME) DOWNWARD QG VERTICAL VELOCITIES AND STRONG COLD ADVECTION BEHIND THE TROUGH WILL HELP TO PLOW NORTHEASTERN COLORADO WITH STRONG WINDS BEGINNING AFTER MIDNIGHT. WILL LIKELY SEE BLOWING SNOW IN THE HIGH COUNTRY AND SOME BLOWING DUST OUT ON THE PLAINS CREATING DANGEROUS DRIVING CONDITIONS IN REDUCED VISIBILITIES. DRIVING WILL BE DANGEROUS ESPECIALLY OVER EAST TO WEST ROADS IN THE NORTHEASTERN CORNER OF THE STATE WITH GUSTS OF 60 TO 70 MPH POSSIBLE. THE MOUNTAINS AND FOOTHILLS WILL LIKELY HAVE GUSTS UP TO 80 MPH. THE LOWS TONIGHT WILL BE MODERATED BY THE INCREASING WINDS WITH READINGS NEAR OR ABOVE FREEZING OVER THE PLAINS. HIGHS TOMORROW WILL MOST LIKELY HAPPEN BEFORE NOON AS THE COLD ADVECTION SPREADS ACROSS THE STATE NORTHWEST TO SOUTHEAST. LIGHT SNOW WILL OCCUR OVER MAINLY THE NORTHERN MOUNTAINS WITH UP TO 3 INCHES EXPECTED THROUGH TOMORROW AFTERNOON. WE MAY SEE A FEW LIGHT RAIN AND SNOW SHOWERS OVER THE FAR NORTHEASTERN PLAINS...THOUGH MOST OF IT WILL REMAIN IN WYOMING AND NEBRASKA. LONG TERM...WINDS WILL DECREASE RATHER QUICKLY WITH THE LOSS OF STRONG DOWNWARD MOTION AND A WEAKENING PRESSURE GRADIENT. HOWEVER...THE NORTHEAST CORNER WILL BE THE LAST TO SEE THE HIGH WINDS DECREASE SO THE WARNING THERE WILL BE CONTINUED INTO THE EARLY EVENING HOURS. OTHERWISE...WITH CLEAR SKIES AND DECREASING WINDS...DECENT RADIATIONAL COOLING SUPPORTS LOW TEMPERATURES IN THE TEENS ACROSS THE PLAINS AND MOSTLY BELOW ZERO READINGS IN THE MOUNTAINS AND HIGH MOUNTAIN VALLEYS. BY SUNDAY...LARGE SURFACE HIGH PRESSURE OVER THE REGION WILL BRING LIGHT WINDS. TEMPERATURES WILL BE SLOW TO WARM WITH HIGH TEMPERATURES A COUPLE DEGREES BELOW NORMAL DESPITE MOSTLY SUNNY SKIES. FOR MONDAY THROUGH THURSDAY...THE MAIN FEATURE WILL BE THE UPPER LEVEL RIDGE OVER THE CENTRAL AND SOUTHERN ROCKIES. A WEAK BACKDOOR COLD FRONT MAY SNEAK ACROSS THE PLAINS LATE TUESDAY INTO EARLY WEDNESDAY...BUT OVERALL A GRADUAL WARMING TREND CAN BE EXPECTED THESE FOUR DAYS WITH DRY WEATHER AND ABOVE NORMAL TEMPERATURES. THE MEDIUM RANGE MODELS POINT TOWARD WEAK TROUGHINESS MOVING INTO THE ROCKIES BY NEXT WEEKEND...SO HAVE INTRODUCED COOLER TEMPERATURES FOR FRIDAY AND A SLIGHT CHANCE OF SNOW IN THE HIGH COUNTRY. AVIATION...VFR CONDITIONS EXPECTED FOR THE NEXT 24 HOURS. EXPECTING MAINLY SOUTHERLY TO SOUTHWESTERLY WINDS THIS AFTERNOON THROUGH TONIGHT AS A SURFACE TROUGH DEEPENS ALONG THE LEE SIDE OF THE NORTHERN ROCKIES AND DOWN INTO TEXAS. STILL BELIEVE WE WON'T COMPLETELY DECOUPLE OVER THE PLAINS TONIGHT...SO WEILL KEEP TONIGHTS WINDS OUT OF THE SOUTHWEST AND INCREASING THROUGH THE NIGHT. STRONG WEST-NORTHWEST WINDS EXPECTED AFTER 15Z SATURDAY WITH GUSTS 50 KTS OR GREATER AROUND THE NOON HOUR AT ALL AIRPORTS. WINDS ARE EXPECTED TO DECREASE BETWEEN 22Z AND 00Z. && .BOU WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING FROM 8 AM TO 7 PM MST SATURDAY FOR COZ042- 048>051. HIGH WIND WARNING UNTIL 5 PM MST SATURDAY FOR COZ033>036. HIGH WIND WARNING FROM 8 AM TO 5 PM MST SATURDAY FOR COZ038>041- 043>047. && SHORT TERM...RJK/KRIEDERMAN LONG TERM....BARJENBRUCH AVIATION...RJK/KRIEDERMAN
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DENVER CO 1055 AM MST FRI DEC 30 2011 COZ030>051-311300- 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- 1055 AM MST FRI DEC 30 2011 ...HIGH WIND WARNING FOR THE FRONT RANGE MOUNTAINS...FOOTHILLS...AND ALL OF THE NORTHEAST PLAINS OF COLORADO... THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL COLORADO. .DAY ONE...TODAY AND TONIGHT WINDS WILL CONTINUE IN THE HIGH COUNTRY TODAY...BUT STRONGER WINDS WILL ARRIVE AFTER MIDNIGHT TONIGHT. STRONG DOWNWARD MOTION...A 130 KT JET AND STRONG COLD ADVECTION WILL COMBINE TO SPREAD HIGH WINDS OVER MOST OF NORTHEASTERN COLORADO...STARTING AFTER MIDNIGHT TONIGHT OVER THE MOUNTAINS AND FOOTHILLS. STRONG WINDS OF 30 TO 50 MPH WITH GUSTS AS HIGH AS 80 MPH ARE EXPECTED. SNOW ON THE GROUND AS WELL AS SOME LIGHT SNOW DUE TO FALL AFTER MIDNIGHT OVER THE HIGH MOUNTAINS WILL BE PICKED UP BY THE STRONG WINDS TO CREATE HAZARDOUS DRIVING CONDITIONS. A COLD FRONT WILL SURGE INTO THE MOUNTAINS OF NORTHERN COLORADO AROUND SUNRISE SATURDAY. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY HIGH WINDS WILL QUICKLY SPREAD FROM THE FRONT RANGE EASTWARD ACROSS THE PLAINS WITH THE PASSAGE OF A FAST MOVING UPPER LEVEL DISTURBANCE AND COLD FRONT SATURDAY MORNING. WIND GUSTS IN EXCESS OF 65 MPH WILL BE COMMON. THE MOUNTAINS WILL RECEIVE A LIGHT SNOWFALL BUT THE STRONG WINDS WILL PRODUCE AREAS OF BLOWING SNOW AND POOR VISIBILITIES. MEANWHILE...ON THE EASTERN PLAINS THAT HAVE RECEIVED LESS SNOWFALL IN THE LAST COUPLE WEEKS...BLOWING DUST WILL LIKELY CREATE HAZARDOUS DRIVING CONDITIONS WITH NEAR ZERO VISIBILITIES IN SPOTS. DRIVERS OF HIGH PROFILE VEHICLES SHOULD AVOID TRAVEL ON SATURDAY. SEMI-TRAILERS MAY BE BLOWN OFF THE ROAD DUE TO STRONG CROSS WINDS. WINDS WILL DECREASE QUICKLY SATURDAY NIGHT. AFTER A SEASONABLY COOL DAY SUNDAY...EXPECT A RETURN TO ABOVE NORMAL TEMPERATURES FOR MUCH OF NEXT WEEK WITH DRY CONDITIONS PREVAILING UNDER A RIDGE OF HIGH PRESSURE. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT. KRIEDERMAN/BARJENBRUCH
The national radar mosaic for the moment the first event began.
17 high wind. Local standard time, as filed.
A driver was killed when he was impaled in the chest by a falling branch. The branch. about 3 feet in length and 3 inches in diameter, flew through into the windshield and fatally wounded him.
The driver of a Freghtliner truck and trailer was injured when his truck was blown off Interstate 76 at mile point 123. The vehicle came to rest on its side. Several other accidents were also reported. The dangerous winds forced the closure of I-76 for high profile vehicles until they subsided.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| High Wind, Boulder & Jefferson Counties Below 6000 Feet / W Broomfield County | 2011-12-31 | 61 | Male | Vehicle/Towed Trailer | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2011Every state in 2011This day in weather historyWarnings in Colorado, December 2011
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 357338, 357339, 357340, 357341, 357342, 357343, 357344, 357345, 357346, 357347, 357348, 357349, 357350, 357351, 357352, 357353, 357354.