High winds developed in the Front Range mountains and foothills. Peak wind gust reports included: 98 mph, 2 miles south-southeast of Gold Hill, 91 mph, 3 miles south of Gold Hill; 89 mph near Aspen Springs; 86 mph, 4 miles east-northeast of Nederland; 83 mph, 3 miles southwest of Jefferson; 78 mph near Dumont; 77 mph near Rocky Flats; with 75 mph near Aspen Springs.
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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.
High winds developed in the Front Range mountains and foothills. Peak wind gust reports included: 98 mph, 2 miles south-southeast of Gold Hill, 91 mph, 3 miles south of Gold Hill; 89 mph near Aspen Springs; 86 mph, 4 miles east-northeast of Nederland; 83 mph, 3 miles southwest of Jefferson; 78 mph near Dumont; 77 mph near Rocky Flats; with 75 mph near Aspen Springs.
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 28, 8:35 PM MST, 5 hours 49 minutes earlier.
Area Forecast Discussion National Weather Service Denver/Boulder CO 835 PM MST Thu Dec 28 2017 .UPDATE... Issued at 757 PM MST Thu Dec 28 2017 Main impact tonight will be the increasing threat of high winds in the mountains and foothills. Plan is to stay the course with the high wind warning starting at midnight. Latest model guidance has the winds increasing after midnight with the peak of high winds between 09-18z Friday morning. Local wind programs showing high wind warning criteria later tonight and Friday morning as surface gradient tightens to over 10mb between GJT and DEN. NAM cross sections showing higher 70-80kt cross barrier flow over the higher east slopes by 12z Friday and then descending down the foothills through mid morning. Forecast soundings also showing increase in mountain top stability around 750mb which should help in wave amplification into the lower foothills early Friday morning. Wave and stability break down by mid afternoon which will result in decreasing winds in the foothills. Peak wind gusts through this evening could get close to 90 mph with this high wind event. && .SHORT TERM...(This evening through Friday) Issued at 245 PM MST Thu Dec 28 2017 Winds have relaxed across the mountains today, and a weak surge brought in cooler air from the east, with temperatures nearly steady or slowly falling along the Front Range where we had started the day so mild. With regard to winds, we've already upgraded to a High Wind Warning for the Front Range Mountains and Foothills. This appears to be a brute force event with cross mountain flow increasing to 50-55 knots and low/mid level pressure gradients increasing by 12Z. There's not much of a mountain top stable layer, so at this time, we don't see a tremendous amount of mountain wave enhancement. Thus, we'll keep the warnings confined to areas above 6000 feet but mention some gusty winds on the nearby plains. The stronger winds on the nearby plains will likely hold off til late tonight or more likely Friday as inversions break. High winds in the mountains and foothills will gradually taper off Friday afternoon as the gradient relaxes. Warmest temperatures on Friday will once again occur in/near the foothills. Denver should see highs near 60F and possibly a few degrees above that with sufficient downslope. The stronger inversions will still be difficult to break in the lower elevations of the plains, so hard to say exactly how much warmup occurs there, but should see a good 10-15 degrees moderation from today. We do expect another push of the arctic air to reach the plains by mid afternoon with falling temperatures thereafter. .LONG TERM...(Friday night through Thursday) Issued at 139 PM MST Thu Dec 28 2017 Continued strong NW pattern over the region through next week. For Friday night into Saturday a cold front will back into NE Colorado bringing a shallow cold airmass into the lower foothills. This airmass will inch across the plains through the morning hours on Saturday fighting against the downsloping winds off the foothills and Palmer Divide. The line of colder temperatures is difficult to pin down at this time but expect highs in the 20s over the far eastern plains with 30s closer to the Wyoming border and slightly warmer south with lower 40s possible over Denver. Given the strength of the shallow airmass clouds could move in and stay creating highs only in the 30s over Denver. By Saturday night into Sunday morning the right entrance region of the upper jet will skirt across the NE corner of the state bringing just enough lift to create light snow and flurries over the plains. The mountains will see some lift and higher moisture that will help to drop a few inches of snow by Sunday evening. Highs on sunday will stay cold in the 20s with lows overnight into Monday in the teens and single digits. For the start of next week Monday will be dry with temperatures rebounding into the upper 20s to lower 30s. Moisture will increase ahead of the next upper level feature bringing a chance of snow to the mountains by Monday evening and a slight chance on the plains with the help of a jet. Subsidence will increase behind the trough drying out conditions and slowly increasing temperatures to near normal by Wednesday. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 757 PM MST Thu Dec 28 2017 Surface winds have shifted s-se at APA/DEN and will continue with drainage winds through the night. Expect increasing gusty winds at BJC later tonight and possible peak gusts up to 45-50kt Friday morning. Winds will be much lighter at APA/DEN however with the strong gradient developing expect some gusts up to 30kt at KDEN as well by mid morning hours. && .BOU WATCHES/WARNINGS/ADVISORIES... High Wind Warning from midnight tonight to 3 PM MST Friday for COZ033>036. && UPDATE...Entrekin SHORT TERM...Barjenbruch LONG TERM...Bowen AVIATION...Entrekin
Hazardous Weather Outlook National Weather Service Denver/Boulder CO 1053 AM MST Thu Dec 28 2017 COZ030>051-291800- 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- 1053 AM MST Thu Dec 28 2017 ...HIGH WIND WARNING FRONT RANGE MOUNTAINS AND FOOTHILLS MIDNIGHT TONIGHT UNTIL 3 PM FRIDAY... This hazardous weather outlook is for northeast and north central Colorado. .DAY ONE...Today and Tonight Winds across the Front Range Mountains and Foothills will become stronger toward midnight tonight, with potentially damaging winds developing in the early morning hours Friday. Peak gusts of 75 to 85 mph will be possible above timberline, through wind prone canyons such as I-70 near Georgetown, and over the higher ridges in the foothills west of Boulder and Fort Collins. In lower elevations including the plains and I-25 Corridor, wind will be lighter. However, a few gusts into the 40-55 mph range will be possible near the base of the foothills including Boulder and Golden. Stronger gusts will also likely spill onto the I-25 Corridor near the Wyoming border. .DAYS TWO THROUGH SEVEN...Friday through Wednesday Strong winds are expected to continue in the mountains, foothills, and portions of the western plains Friday. An arctic airmass will back into northeast Colorado Saturday bringing cloudy conditions and cold temperatures to the northeastern plains with snow possible by Sunday morning for the mountains and plains areas. The cooler temperatures are expected to continue through Monday before a warming trend starting Tuesday. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed today or tonight. However, any reports of strong or damaging winds will be appreciated.
The national radar mosaic for the moment the first event began.
3 high wind. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2017Every state in 2017This day in weather historyWarnings in Colorado, December 2017
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: 730803, 730804, 730805.