Strong winds knocked a huge tree into a house in Loveland. No one was injured after the tree fell into the house, which included a 10-week-old baby.
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The episode as NWS BOU wrote it up.
Strong winds knocked a huge tree into a house in Loveland. No one was injured after the tree fell into the house, which included a 10-week-old baby. The house suffered extensive damage and the family was displaced.
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 Feb 21, 3:41 AM MST, 49 minutes earlier.
Area Forecast Discussion National Weather Service Denver/Boulder CO 341 AM MST Tue Feb 21 2017 .SHORT TERM...(Today and tonight) Issued at 341 AM MST Tue Feb 21 2017 Winds are already roaring outside the office. They picked up out of the west at 2 AM with gusts over 60 mph in town and close to 70 mph at the NCAR mesa lab and at some of the foothill sites in Boulder and North Jefferson Counties. Cleary the biggest concern today will be the strong gusty west winds and very dry air across the Plains below 7500 feet. A handful of fires grew quickly on Monday when winds were significantly weaker than they will be during the day today. Red flag warning conditions will occur much of the day today, please see the fire weather discussion below for details. High-res models are showing a mountain wave developing this morning backed up by current observations, and combined with deep vertical mixing of higher momemtum aloft, strong winds should have little trouble impacting the Plains and spreading east. At this time the winds at 600 mb and above do not appear to be excessive but are perpendicular to the terrain gradient, and in the 45-50 kt range. Expect winds in and near the foothills to gust up to 75 mph across the favored windy spots this morning through midday. Elsewhere across the Plains, winds should be in the 25-35 mph range with higher gusts likely through the afternoon. Winds should be strongest through mid afternoon when the pressure gradient at the surface relaxes and the mountain wave breaks down. The strong downslope winds will lead to a significant warm up east of the Continental Divide. Denver's record for the date is 71 degrees, and that should be broken by 2-4 degrees today with ease. Low to mid 70s are expected across the Plains. The mountains west of the Continental Divide will see a modest increase in temperature since they will not have the significant advantage of downslope flow. 700 mb temps warm a few degC today vs. Monday so highs should be in the low 40s across the higher terrain and mid 40s to low 50s below 8000 feet. Tonight winds will be lighter across the Plains east of I-25, but given the warm daytime temperatures, lows will be warmer than normal. Winds look to stay up west of I-25 in and near the foothills and another mountain wave should develop leading to locally gusty winds near the foothills Wednesday morning, but conditions are far less favorable for strong winds compared to today. In the mountains, a 120 kt jet will advect Pacific moisture into western Colorado starting tonight. Snow is possible in the mountains starting early Wednesday morning, generally along and north of I-70 with the best chance occuring across the Park Range. .LONG TERM...(Wednesday through Monday) Issued at 341 AM MST Tue Feb 21 2017 A change is at hand. Models have pretty strong west-southwesterly flow aloft on Wednesday and Wednesday night as an upper trough develops over the northwestern quarter of the United States. There is a long wave upper trough carving out over much of western North America and Colorado is in it Thursday and Thursday night. There is pretty decent upward vertical velocity for the CWA on the QG Omega fields Wednesday through Thursday night. The boundary layer winds are downsloping Wednesday morning, then a cold front moves across the forecast area through the afternoon. There is upslope Wednesday night and Thursday. It looks like another surge and more due northerly upslope is progged for late Thursday and Thursday evening. For moisture, there is a little in the mountains on Wednesday and not much over the plains. Moisture increases in the mountains Wednesday night and also on the plains after midnight, especially for the western half. Moisture continues to increase and deepen on Thursday, with the NAM showing more than the rest of the models. Thursday night shows widespread moisture for all the CWA. The QPF fields have a tad of measurable precipitation over the mountains on Wednesday, then a bit more Wednesday night. On Thursday, there is measurable precipitation over much of the CWA; same for Thursday night. In the mountains, initially there is poor orographic enhancement, but later Thursday morning through Thursday night, it becomes somewhat better. So for pops in the mountains, will go with 60-90%s Wednesday through Thursday night. As far as potential highlights, the best snowfall looks to occur from 06Z Thursday through 00Z Friday. For the plains, will need to start pops Wednesday night over the northwest, then get all the plains involved by noon Thursday and continuing through Thursday night. Will go with "likely"s, especially Thursday afternoon and evening. Accumulations on the plains will not be much. For temperatures, Wednesday's highs are 2-4 C cooler than this afternoon's. With a colder, new airmass in place, Thursday highs look to be 9-14 C colder than Wednesday's. For the later days, Friday through Monday, models have the mean trough sliding east of Colorado by Friday. Very strong west- northwesterly flow aloft is progged Friday night into Sunday. Upper ridging moves in later Sunday and Sunday night and by Monday, strong southwesterly flow aloft is in place ahead of the next approaching trough. There is enough moisture embedded in the flow to keep some mountains pops for snow going much of the time. Temperatures will stay below seasonal normals through Sunday, then warm-up on Monday. && .AVIATION...(For the 12Z TAFS through 12Z Wednesday morning) Issued at 341 AM MST Tue Feb 21 2017 VFR conditions to continue through Wednesday. Winds will be a challenge today at all three terminals. Confidence is high that the prevailing direction will be westerly through the early evening today. Winds are already howling at BJC and should continue that way through the afternoon. DEN and APA have shifted to the W and WNW. All high res models show the strong downslope push reaching DEN and APA around 16Z. Confidence is high in this wind shift occuring within an hour or so of 16Z. With the wind shift to the west, strong and gusty winds will occur through late afternoon. Expect sustained 20-25kts with gusts to 35 kts. Winds will weaken this evening and turn to drainage after 02Z at all three terminals. && .FIRE WEATHER... Issued at 341 AM MST Tue Feb 21 2017 Strong west flow aloft will be forced down the east slopes of the Rockies today and spread out across the Plains. With record breaking temperatures, strong west winds, and relative humidity values around 10 percent red flag warning conditions will easily be met below 7500 feet MSL east of the mountains to the Kansas border. Winds will be especially strong near the foothills and along the Wynoming border. Several fires have already occurred over the last 24 hours given the dry fuels, and the weather will only exacerbate the threat of rapid fire growth from now through early evening. Relative humidity values will improve a little overnight but expect another round of gusty west winds Wednesday morning in and near the foothills. Do not expect warning criteria Wednesday morning given the approach of a Pacific storm system and an increase in moisture. Additionally, the winds should not be as strong east of I-25 Wednesday morning. There will be one more day of above normal temperatures on Wednesday, then an upper level storm moves in later along with a significantly colder airmass by Wednesday night continuing into the weekend. Moisture increases and snow is expected in the mountains through Saturday. The plains will see some snow Thursday into Friday. It will be good to have the moisture but significant amounts are unlikely. && .BOU WATCHES/WARNINGS/ADVISORIES... Red Flag Warning from 11 AM this morning to 6 PM MST this evening for COZ215-216-238>251. && SHORT TERM...Schlatter LONG TERM...RJK AVIATION...Schlatter FIRE WEATHER...Schlatter/RJK
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DENVER/BOULDER CO 1141 AM MST Mon Feb 20 2017 COZ030>051-211845- 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- 1141 AM MST Mon Feb 20 2017 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL COLORADO. .DAY ONE...TODAY AND TONIGHT the combination of above normal temperatures and gusty northwest winds will result in elevated fire weather conditions across the northeast plain this afternoon. Occasional gusts up to 35 mph will be possible, mainly east of a line from around new raymer to last chance through mid afternoon. In and near the Foothills, west winds could increase overnight with some gusts up to 50 mph possible. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY Tuesday and Wednesday it will be dry except for a slight chance of snow showers in the mountains. Fire Danger will remain high over the foothills and plains due to well above normal temperatures and gusty winds at times. The next storm system is expected to reach the area by Thursday. This system will bring a snow to the mountains with a good chance for snow across the lower elevations. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be required today or tonight.
The national radar mosaic for the moment the first event began.
1 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, February 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: 671851.