A storm system moved across the region and produced a period of very strong winds in the foothills and northeast plains of Colorado. In and near the foothills, peak wind gusts included: 85 mph, 3 miles southwest of Rocky Flats; 81 mph, 3 miles north-northeast of White Ranch Open Space; 80 mph, 2 miles north-northwest of Rocky Flats; 79 mph, 3 miles east-northeast of Bergen Park; 78 mph near…
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The episode as NWS BOU wrote it up.
A storm system moved across the region and produced a period of very strong winds in the foothills and northeast plains of Colorado. In and near the foothills, peak wind gusts included: 85 mph, 3 miles southwest of Rocky Flats; 81 mph, 3 miles north-northeast of White Ranch Open Space; 80 mph, 2 miles north-northwest of Rocky Flats; 79 mph, 3 miles east-northeast of Bergen Park; 78 mph near Crisman and NCAR Mesa Lab; 75 mph, 3 miles north-northeast of Pleasant View. Across the northeast plains, peak gusts included: 64 mph near Log Lane Village; 63 mph, 8 miles south of Holyoke; 60 mph at Akron; 58 mph, 6 miles southwest of Carr and near Natural Fort Rest Area.
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 17, 9:41 AM MST, 1 hour 19 minutes earlier.
Area Forecast Discussion National Weather Service Denver/Boulder CO 941 AM MST Fri Jan 17 2020 .UPDATE... Issued at 940 AM MST Fri Jan 17 2020 Forecast is on track regarding winds and mountain snow. We did have to add some fog across the eastern plains this morning with locally reduced visibility, but that will be eroding to the east by the noon hour. With regard to the rest of the forecast, radar and satellite show snow rapidly filling in across the high country, with pockets of heavy snow and 1-2" per hour rates over the central Colorado mountains. These heavier snow showers will be spreading through Summit County in the late morning to mid afternoon hours (still snowing hard in the northern Wasatch of Utah), before precipitation rates gradually decrease late this afternoon as subsidence behind the passing trough moves in. Travel will be hazardous to say the least during these heavier snow showers. The plains wind is not as clear as it was yesterday, as the latest observed pressure gradients are running lower than forecast. Part of this may be due to the lead short wave with relative pressure falls still on the west slope off Colorado. However, there are very strong pressure rises now organizing in Utah. We could get one push of winds with the convective activity and isolated to scattered showers spreading east across the plains, but then one last and potentially stronger surge as the short wave finally moves across late this afternoon and early evening, coinciding with the strongest pressure gradients and isallobaric acceleration as the pressure rise max moves over the Front Range. && .SHORT TERM...(Today and tonight) Issued at 253 AM MST Fri Jan 17 2020 Strong fast moving upper level trough located over the Great Basin will race east today across the Central Rockies. Water vapor satellite imagery showing the best lift associated with this trough moving across Utah at this time. As moisture and ridge top winds increase, snow showers are expected to form over the mountains early this morning. Snow will become widespread later this morning when the trough nears the state and lift increases. The airmass will be unstable with CAPE up to 300 J/kg over the mountains and even across the plains. Some snow showers should be heavy due to the strong lift from the trough and instability. Snowfall rates may reach 1 to 2 inches per hour under the heavier snow showers. This will quickly cause roads to become snow covered. Total snowfall is expected to be 3 to 6 inches with a little more possible under the heavier snow showers. Due to the instability, will have slight chance PoPs along the Front Range and Urban Corridor. If any showers survive crossing the higher terrain, they should be in the form of rain and last only a short time. There is a better chance for rain and snow showers over the northeast corner of the state. Any precipitation from this is expected to be light as well. Strong winds are still expected with this system as it crosses the region. Winds start to get strong early this afternoon, so the 11AM start time may be a little early, but may be off by only a couple of hours. Not enough to change the warning start time. Over far northeast Colorado, the strong winds may not arrive until after sunset. Wind gusts of 50 to 60 mph still appear on track with gusts to 75 mph possible in the wind prone areas along the Front Range. For tonight, the upper level trough will be east of Colorado. Strong subsidence and drying will occur behind it and bring the snow showers to an end this evening. A stable layer above ridge top level may help a mountain wave form tonight, so the high winds may linger through the evening and past midnight in and near the foothills. Plan on keeping the High Wind Warning in effect through 2AM Saturday. Cold air advection behind this system will result in colder overnight temperatures. Expect teens across the Front Range and eastern plains with single digits over the higher terrain. .LONG TERM...(Saturday through Thursday) Issued at 253 AM MST Fri Jan 17 2020 After this latest fast moving storms system exits the state early Saturday, an extended period of dry and mild weather should be in store for northern Colorado through the middle of next week. Will look for the potential for a switch-over to a colder and moist period for late next week. As we head into Saturday, despite strong subsidence throughout all levels of the atmosphere, a weakening mid and upper level height gradient will take place into Sunday as a ridge axis begins to develop across the western US on the heels of the ejecting windy trough to our east. Cross sections indicate just enough shallow Pacific moisture riding in the prevailing flow to potentially provide some light snow showers over the highest terrain Saturday from weak orographics in the the weakening flow. For the most part however, the high country will begin a drying trend which should persist into the beginning of next week. By midday Sunday, the ridge over the western US strengthens further while keeping the region under moderate northwesterly flow aloft. In this flow, a very weak and dry disturbance will race across the northern US plains while dragging a weak and dry surface surge onto the central high plains. This wind shift of near isothermal temperatures will likely anti-cyclone into northeast Colorado off the Cheyenne Ridge keeping the plains in easterly flow and temps mostly in the cool 40s to near 50 for Sunday. For Monday, the ridge amplifies and maximized over the entire Rockies from southwest Canada to Mexico. This will give the region calm and persistently dry and mild conditions for Monday. Meanwhile, the next weather maker for Colorado begins to affect the Pacific northwest as it moves onshore during the day Tuesday. Out ahead, a weak wave will bring mid and upper level moisture across the state along with possibility for some isolated light snow showers for the very highest terrain. Across the lower elevations however, Tuesday should be the warmest day of the extended period as a weak lee trough sets up and some weak southwesterly winds get going across the foothills and Palmer. Will expect a day with mid and high level cloudiness and filtered sunshine. As the Pacific trough enters the northern and central Rockies Wednesday, fairly significant differences stand out between the long range models. The GFS and Canadian suggest the closed-low storm track taking a southeasterly direction into the UT/CO vicinity while building another strong and amplified ridge out across the west coast in it's wake. The ECM on the other hand prefers making this Pacific wave just another windy disturbance in a train of weak storms systems lined up across the northeast Pacific and Pacific northwest region. A few more model runs will reveal better clues about this next storm. && .AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon) Issued at 940 AM MST Fri Jan 17 2020 Biggest aviation concern will be strong winds this afternoon and early evening. Southerly winds are expected to turn more southwest or westerly with the arrival of isolated showers/virga aloft 17Z-19Z. Between 19Z and 21Z winds are expected to become west to west/northwest with gusts reaching 40 knots. We should see these strong winds holding until about 02Z, and then slowly decrease through 04Z-06Z. There is a chance we could see 50 knot gusts at KDEN, the most likely time for that would be 22Z-02Z with the passage of the upper level trough. Blowing dust with temporary reductions in visibility would be possible should gusts exceed 40-45 knots. After 04Z-06Z, wind direction may become variable with a tilt toward a developing anticyclonic flow across the metro area airports. Meanwhile, KBJC may see gusts to 50-60 knots if there's enough mountain wave amplification through about 09Z. && .BOU WATCHES/WARNINGS/ADVISORIES... High Wind Warning from 1 PM this afternoon to 2 AM MST Saturday for COZ040>051. High Wind Warning until 2 AM MST Saturday for COZ035-036-038-039. Winter Weather Advisory until 5 PM MST this afternoon for COZ031- 033-034. && UPDATE...Barjenbruch SHORT TERM...Meier LONG TERM...Fredin AVIATION...Barjenbruch
Hazardous Weather Outlook National Weather Service Denver/Boulder CO 309 AM MST Fri Jan 17 2020 COZ030>051-181015- 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- 309 AM MST Fri Jan 17 2020 This hazardous weather outlook is for northeast and north central Colorado. .DAY ONE...Today and Tonight A strong quick moving Pacific storm system will move across Colorado today. This system will bring strong winds along with mountain snow. In the high country, snow will develop this morning. Roads will become snow covered and slippery, and visibility will be reduced due to blowing snow. There may be a brief period of more difficult travel late Friday morning into early afternoon with a burst of heavier snowfall. Snow will then taper off by Friday evening. Total accumulations of 3 to 6 inches can be expected, with up to 8 inches under the heavier snow showers. Across the Front Range Foothills, I-25 Corridor, and adjacent plains, it will become very windy. Peak gusts will reach 50 to 60 mph in most locations, with gusts in excess of 75 mph possible across wind prone areas in and near the foothills. Travelers of high profile vehicles should consider avoiding travel Friday afternoon and evening when the strongest winds will blow. .DAYS TWO THROUGH SEVEN...Saturday through Thursday Dry conditions and decreasing winds can be expected during the morning hours Saturday with areas of blowing snow persisting through the day over higher mountain passes and exposed areas. Dry conditions and mild temperatures are expected for Sunday through Wednesday ahead of the potential for colder and wintry weather for the high country and lower elevations for late Wednesday into Thursday. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed today or tonight.
The national radar mosaic for the moment the first event began.
9 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: 865296, 865297, 865298, 865299, 865300, 865301, 865304, 865308, 865310.