High winds developed in and near the foothills of Boulder, Larimer and northern Jefferson counties. Peak wind gusts included 100 mph, 2 miles north-northwest of Carter Lake; 89 mph in west Longmont; 83 mph at the NCAR Mesa Laboratory, 3 miles northwest of Marshall; 80 mph at the junction of highways 93 and 72.
Every event with a place to put it; 3 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.
High winds developed in and near the foothills of Boulder, Larimer and northern Jefferson counties. Peak wind gusts included 100 mph, 2 miles north-northwest of Carter Lake; 89 mph in west Longmont; 83 mph at the NCAR Mesa Laboratory, 3 miles northwest of Marshall; 80 mph at the junction of highways 93 and 72. A large tree, 8 ft in diameter, was knocked down by the wind near Carter Lake. The tree fell onto a nearby building.
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 Jan 6, 8:10 PM MST, 3 hours 5 minutes earlier.
Area Forecast Discussion National Weather Service Denver/Boulder CO 810 PM MST Mon Jan 6 2020 .UPDATE... Issued at 806 PM MST Mon Jan 6 2020 Main concern tonight through Tuesday morning revolves around the high wind potential for the foothills. Current observations showing wind gusts mainly ranging in the 30-50 mph range with a few higher gusts around 60 mph. Radar imagery showing some enhancement of mountain wave across western Boulder county with highest winds remaining over higher elevations. Latest water vapor imagery and QG diagnostics indicate best subsidence will be after midnight tonight through mid morning on Tuesday and this will coincide with best shear profile for an amplified mountain wave. In addition, forecast soundings indicate strengthening stable layer at 750 mb through the night. Latest HRRR showing peak wind gusts between 08z-15z with max speeds of 60-70kt during this period. Will maintain the high wind warning through Tuesday morning. Elsewhere, winds have decreased over the plains but still some gusty winds up to 35 mph, mainly near the Wyoming border. UPDATE Issued at 451 PM MST Mon Jan 6 2020 Have issued a high wind warning for the Front Range foothills for tonight through Tuesday morning. Looks like another shot of high winds for the foothills tonight through Tuesday morning. Local wind programs are favoring high wind gusts up to 75 mph tonight. This event will be more of a chinook type wind as forecast soundings showing increasing stability at 750mb while cross sections showing cross barrier flow increasing to 50-60 this evening. The subsident flow will not be as strong as the past 2 nights but QG products still showing max subsidence at 12z on Tuesday in the light to moderate range. Shear profile also expected to improve this evening for an amplified mountain wave as the 100kt jet over us now will shift east of Colorado while nose of next jet segment noses into the Nebraska Panhandle by 12z Tuesday. High resolution models of HRRR/RAP showing potential of 60-70kt wind gusts through about 15z on Tuesday, with best potential for the damaging winds after midnight tonight. && .SHORT TERM...(This evening through Tuesday) Issued at 123 PM MST Mon Jan 6 2020 Strong winds continue across the northeast plains of CO this afternoon with moderate mid level subsidence over the northeast plains with peak gusts in the 50-60 mph range earlier today but those stronger gusts are becoming more localized. Will continue with the High Wind Warning this afternoon but see the stronger gusts start to gradually weaken the rest of the afternoon, as the upper trough continues to shift eastward. Highway cams not showing much in the way of impacts regarding snow and strong winds in the mountains so have cancelled the Winter Weather Advisory. Models still show some residual moisture in the high country overnight so will keep isolated to scattered snow showers mentioned on the higher northwest facing slopes, but dry elsewhere. In and near the foothills, strong and gusty downslope winds will continue overnight, with localized gusts in the 60-70 mph range possible. Since these stronger gusts should be more localized, no additional high wind highlights planned for the foothills tonight. Dry northwesterly flow can be expected through the day on Tuesday. It will remain windy in the mountains and foothills but the magnitude of the peak gusts will be less, around 50 mph. Over the northeast plains, breezy at times with temperatures back above normal, in the lower to mid 50s. .LONG TERM...(Tuesday night through Monday) Issued at 350 PM MST Mon Jan 6 2020 Upper ridging is over the forecast area Tuesday night. West- southwesterly flow aloft is in place Wednesday with an upper through to move into the CWA late day. The upper trough axis is just east of the CWA by 12Z Thursday morning. Southwesterly flow aloft comes after that with the next upper trough getting into the CWA by 12Z Friday morning. There is weak upward vertical velocity over the CWA Tuesday night. It gets a bit stronger on Wednesday. By late Wednesday evening, subsidence is over the forecast area. Upward motion returns later Thursday through Thursday night. The low level winds are a mix of normal diurnal trends and downsloping much of the time. Concerning high winds, there is a bit of a mountain wave set-up Tuesday night, but it is not significant. For moisture, it is sparse Tuesday into Wednesday. By Wednesday evening, it increases in the mountains. This continues Thursday, with some moisture getting into the plains later in the afternoon. There is fairly deep moisture in place over much of the CWA Thursday night into Friday morning. There is no measurable precipitation on the QPF fields until late Wednesday. There are some limited amounts over the plains areas Wednesday night through Thursday night. There is a tad over some of the plains Thursday night. No pops through Wednesday morning. Will go with "chance"s in the mountains Wednesday night into Thursday morning, then "likely"s Thursday afternoon and evening. For the plains willsgo with "slight chance"s Thursday night. No highlights. For temperatures, Wednesday's highs are 1-3 C warmer than Tuesday's readings. Thursday's highs are 1-4 C cooler than Wednesday's. For the later days, Friday through Monday, models have the upper trough pushing east of the CWA by Friday evening, with upper ridging moving in. By late Saturday, continuing into Monday an upper trough is over the CWA. It is unsettled, with mainly snow for the mountains through the weekend. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) Issued at 806 PM MST Mon Jan 6 2020 VFR with some mountain wave cloudiness through Tuesday morning. Surface winds will be erratic through the morning given the mountain wave formation with strongest winds expected at BJC, especially after midnight. Could see some of the stronger winds spread out towards DIA later tonight/Tuesday morning but overall confidence is low to medium. Overall winds will decrease Tuesday afternoon and less winds then we had today. && .BOU WATCHES/WARNINGS/ADVISORIES... High Wind Warning until noon MST Tuesday for COZ035-036. && UPDATE...Entrekin SHORT TERM....Coop LONG TERM.....Koop AVIATION...Entrekin
Hazardous Weather Outlook National Weather Service Denver/Boulder CO 1026 AM MST Mon Jan 6 2020 COZ030>051-071730- 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- 1026 AM MST Mon Jan 6 2020 ...HIGH WIND WARNING OVER PARTS OF THE NORTHEAST COLORADO PLAINS THIS AFTERNOON... ...WINTER WEATHER ADVISORY FOR SNOW AND BLOWING SNOW IN THE MOUNTAINS TODAY... This hazardous weather outlook is for northeast and north central Colorado. .DAY ONE...Today and Tonight Strong flow aloft over Colorado today will combine with some moisture in the mountains to produce light snow in the high country. The strong winds aloft will produce windy conditions along the foothills all day and out across the plains through this afternoon. West to northwest winds are expected to increase to 25 to 40 mph with gusts up to 60 mph. Dangerous cross wind conditions will be possible, especially on Interstate 76. Areas of blowing dust may also reduce the visibility at times. In the mountains, light snow will continue mainly along the higher west facing slopes. In addition, the wind will be gusty with peak gusts from 50 to 70 mph above timberline. The gusty Areas of blowing and drifting snow will reduce visibilities at times. High pressure will begin developing by this evening which will bring an end to the mountain snowfall, and diminish the winds across the plains. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday Tuesday will be dry with gusty winds continuing over the higher terrain. The next weather system will bring snow to the mountains Wednesday into Thursday. At this time, significant snowfall amounts are not expected. Across the plains it will turn colder on Thursday with a slight chance of snow Thursday night or Friday. The chance of snow returns to the mountains Saturday continuing into next week. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed today or tonight.
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 2020Every state in 2020This day in weather historyWarnings in Colorado, January 2020
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: 863924, 863922, 863923.