Strong winds develop near the base of the foothills. A peak gust to 76 mph was recorded 3 miles northwest of Marshall.
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The episode as NWS BOU wrote it up.
Strong winds develop near the base of the foothills. A peak gust to 76 mph was recorded 3 miles northwest of Marshall.
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 26, 7:41 PM MST, 2 hours 4 minutes earlier.
Area Forecast Discussion National Weather Service Denver/Boulder CO 741 PM MST Sun Feb 26 2023 .UPDATE... Issued at 729 PM MST Sun Feb 26 2023 No significant changes to the forecast at this time. Latest mesonet observations indicating wind gusts to 60 mph in and near the foothills of Boulder and Jefferson counties. The GJT-DEN 1500 meter pressure gradient continues to increase, near 11 mb at 7 pm, and this tightening gradient should continue this evening. Most of the model data indicate the strongest gusts will develop in the 03-10z period tonight so it still looks like the High Wind Warning is on track. This is supported by the Sangster Model output using the latest NAM12 model as well. The weak convective virga that occurred over the plains has diminished this evening. Main issue tonight will be gusty northwest winds developing overnight, strongest after midnight with gusts up to 40 mph possible northeast of a line from around Fort Collins to Hugo. && .SHORT TERM...(This evening through Monday) Issued at 127 PM MST Sun Feb 26 2023 The fast-moving upper level wave is traversing over Colorado this afternoon, with deeper moisture taking hold over the high country. Snow showers have already initiated over the high terrain and will increase in coverage and intensity later this afternoon and evening. A period of steeper mid level lapse rates (~7-9 C/Km) may lead to a few heavier showers and a quick inch or two for the passes, making for slick travel conditions coinciding with return ski traffic. Snow will be heaviest and most persistent over the Park Range with more favorable orographics, so will maintain the Winter Weather Advisory through tomorrow which includes Rabbit Ears Pass, for accumulations of 6-12". Amounts will be considerably less farther south, generally 1-4" for the I-70 mountain corridor. East of the mountains, we've been observing healthy warm southerly winds across the Denver metro, Palmer Divide and southern plains, which has allowed temperatures to climb into the high 50's to low 60's. Mid level cloud cover will increase in the next few hours, with just enough moisture and instability to spur the development of some high based convective showers. With dry near-surface conditions persisting however, most areas are likely to remain dry, with virga more prevalent for the most part. The other story will be the winds. We're still on track for increasing winds beginning late this afternoon in the foothills and spreading into adjacent plains communities west of I-25. The overall setup is not overly impressive as far as mountain wave amplification goes, as ingredients are hit and miss, and there's still some inconsistency among model guidance. Soundings and cross sections still hint at some weakening of wind speeds with height, suggestive of a mean state critical layer, although have backed off in indicating any flow reversal. Flow aloft is generally not supportive of a high impact event (limited cross barrier flow, displaced jet), but surface pressure gradients should be hefty enough to drive much of the wind. Ultimately, despite a slight downward trend in peak gust potential across most 12Z guidance, HREF still indicates 60-80% probability of reaching high wind criteria (75 mph) for portions of the foothills per DESI interface, bleeding into communities like Boulder and Lyons. Thus, have opted to upgrade the watch to a warning. The strongest winds will largely be confined to the area between Hwy 34 and I-70 along and just east of the foothills. Winds will remain strong overnight, and weaken relatively quickly near sunrise. With the gusty overnight conditions, have increased forecast lows for communities at the base of the foothills, and it's certainly possible temperatures will remain above 40 F locally. With the downslope flow subsiding tomorrow and with cold air advection in place, most areas will be several degrees cooler, with highs mostly in the 40's outside of the Denver metro, which should crack 50 F. Dry conditions will prevail except for a few high-elevation snow showers, primarily for the Front Range. .LONG TERM...(Monday night through Sunday) Issued at 210 PM MST Sun Feb 26 2023 Strong west-southwesterly flow aloft will dominate over the forecast area Monday night into Wednesday morning. There is a weak upper trough embedded in the flow late Monday night but it weakens by Tuesday morning. Wind speeds are progged from 90 to 140 knots Monday night into Wednesday morning. There should be enough moisture in the flow for light snow in the high mountains. The best in Zone 31. Moisture remains lacking over the plains Monday night through Tuesday night. The southwesterly flow aloft should decrease through the day Wednesday into the evening as an upper trough approaches. By 12Z Thursday morning, the trough axis is over the western CWA with a closed low at the bottom of the trough over western central New Mexico. There is fairly strong QG ascent ahead of the trough starting early Wednesday continue into Thursday morning. Moisture is progged to increase and deepen through the day Wednesday. Models continue to point to a widespread light snowfall for much of the CWA with this system. Snowfall amounts do not look significant at this time. Temperature-wise, Tuesday's highs look to be around seasonal normals, with Wednesday's highs 2-4 C colder then Tuesday's. For the later days, Thursday through Sunday, models show the upper trough push eastward across the CWA on Thursday with northwesterly flow aloft Thursday night and Friday. A weak upper trough in the northwesterly flow will move across Colorado Friday afternoon and evening. Flat upper ridging is in place Saturday with stronger zonal flow aloft for Sunday. There is some moisture around both Thursday and Friday. Saturday and Sunday are dry for all the forecast area. The cold day looks to be Thursday with gradual warming through the weekend. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 451 PM MST Sun Feb 26 2023 VFR conditions are expected through the period. BKN mid level clouds 100-120 possible through 02z, with sct lower coverage 050-070. NW winds will weaken at KDEN/APA, but may keep more of a W/SW component after 02-03z vs a true drainage wind. Mountain wave amplification is still expected to produce stronger W/NW winds at KBJC, with gusts 40-45kts possible 03z-11z tonight, then weakening a bit Monday morning. && .BOU WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 5 PM MST Monday for COZ031. High Wind Warning until 6 AM MST Monday for COZ035-036-038-039. && UPDATE...Cooper SHORT TERM...Rodriguez LONG TERM....RJK AVIATION...Cooper
Hazardous Weather Outlook National Weather Service Denver/Boulder CO 1152 AM MST Sun Feb 26 2023 COZ030>051-271900- 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- 1152 AM MST Sun Feb 26 2023 This hazardous weather outlook is for northeast and north central Colorado. .DAY ONE...Today and Tonight A quick-hitting system will bring a period of strong winds to the high terrain, foothills, and adjacent plains areas west of I-25 late this afternoon through early Monday morning, with localized gusts to 75 mph expected. Additionally, the mountains will see a few inches of snow over the next 24-36 hours, generally in the 2-5 inch range for the I-70 mountain corridor, with up to 5-10 inches for the Rabbit Ears Pass area in the Park Range. .DAYS TWO THROUGH SEVEN...Monday through Saturday Winds will gradually decrease on Monday, then redevelop again by Tuesday afternoon with gusts up to 40 mph on the plains and up to 60 mph over the higher mountains and east slopes. Periods of light snow will continue over the ridges, with a little snow possible in the valleys again Monday night and Tuesday. Snow is expected for much of the forecast area Wednesday afternoon into Thursday along with colder temperatures. There will be a chance of snow showers in the high mountains Friday and Saturday. .SPOTTER INFORMATION STATEMENT... Reports of high winds or wind damage will be appreciated.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
704 PM MST SUN FEB 26 2023
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0644 PM NON-TSTM WND GST 2 NNW GENESEE 39.71N 105.29W
02/26/2023 M61 MPH JEFFERSON CO MESONET
&&
ADPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
705 PM MST SUN FEB 26 2023
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0512 PM NON-TSTM WND GST 3 SW ROCKY FLATS 39.87N 105.24W
02/26/2023 M62 MPH JEFFERSON CO MESONET
&&
ADPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
945 PM MST SUN FEB 26 2023
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0910 PM NON-TSTM WND GST 3 NW MARSHALL 39.98N 105.28W
02/26/2023 M76 MPH BOULDER CO MESONET
&&
ADThe 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 2023Every state in 2023This day in weather historyWarnings in Colorado, February 2023
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: 1083428.