As an upper level system approached from the west, a cold front dropped south through the region during this period. This assisted with a period of deep upslope flow focused across the Pikes Peak region, supporting the highest snowfall totals in this location.
Every event with a place to put it; 5 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 PUB wrote it up.
As an upper level system approached from the west, a cold front dropped south through the region during this period. This assisted with a period of deep upslope flow focused across the Pikes Peak region, supporting the highest snowfall totals in this location. Highest totals were in the 8 to 10 inch range across the Pikes Peak region.
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 Pueblo, CO wrote its last area forecast discussion before the first event at Mar 20, 10:28 PM MST, 1 hour 52 minutes earlier.
Area Forecast Discussion National Weather Service Pueblo CO 1128 PM MDT Sat Mar 20 2021 .SHORT TERM...(This evening through Sunday) Issued at 253 PM MDT Sat Mar 20 2021 Current satellite imagery shows mostly clear skies across southern Colorado, while observations show strong, gusty winds picking up across the area. Strong winds will be the main forecast concern through the rest of the day today. A pseudo mountain wave type setup stands in place over the southeast mountains, and winds over much of the area are expected to remain gusty through the rest of the evening, weakening after midnight. Gusts upwards of 35-40 mph have been seen in observations, and over higher elevations and in gap flows gusts to around 50 mph cannot be ruled out. The main areas of concern for winds will be the San Luis and Wet Mountain Valleys. Along with this, some blowing dust will also be possible in drier areas with gusty winds, would could reduce visibility over localized areas. Although downslope wind storm conditions are not expected, locally stronger winds are possible. With the winds present and low relative humidity, fire weather conditions would normally be widespread today, however due to recent precipitation, the fuels are much too moist and the threat has been mostly mitigated for now. During the overnight tonight the first embedded shortwave associated with the incoming trough will reach southern Colorado, which will result in the beginning of moderate snowfall over the mountains. The precipitation will start over the eastern San Juans and the Continental Divide before moving over the Sangres. Tomorrow, the precipitation will continue to expand, setting in over the rest of the mountains as well as the Pikes Peak region and the Palmer Divide. The main challenge up there with snow amounts will be temperatures. Today's highs are well on the warm side, with low-mid 70s over I-25 expected, and while tomorrow is looking to be over 10 degrees cooler, temperatures will still be well above freezing, and the roads will be warm. As precip sets in over northern El Paso County, anything that doesn't fall as rain will likely melt as soon as it comes into contact with the roads. If snow is able to accumulate quickly enough it could stick, but when the rates lighten it will likely lead to wet, slushy roads. Working off of that, the majority of the precipitation over the Palmer Divide area will occur in the beginning of the long-term forecast period, and will likely be dependent on Sunday's high temperatures and the track of the low heading into Sunday night. .LONG TERM...(Sunday night through Saturday) Issued at 253 PM MDT Sat Mar 20 2021 Upward motion increases quickly across the area Sunday evening, as low/mid level upslope flow deepens ahead of upper level trough digging southward through Colorado. Snowfall will become widespread over the higher terrain after 00z as forcing increases, while rain/snow spread across the I-25 corridor and onto the adjacent plains. Best lift through about 06z seems to be focused along and north of the Arkansas River, with most models suggesting snowfall rates of at least 1-2 inches per hour over the Palmer Divide and Teller County through much of the evening. After 06z, heavier snow shifts south toward the nrn Sangres/Wets, as surface and mid level circulations drop southeastward toward the TX Panhandle. After 12z, precip then moves slowly eastward across the plains, though snow showers and flurries may linger most of the day over the mountains and I-25 corridor. Rain/snow line will start at 6-7k feet MSL Sunday evening, then gradually sink toward 5k feet around midnight before falling toward 4k feet Mon morning. Snow amounts around COS and PUB will be tricky and depend on the timing of the changeover, but wouldn't be surprised to see several inches of heavy wet snow both areas by Mon morning, though roads may stay just slushy/wet given warm ground and air temps staying right around freezing. Plains even more questionable, and suspect accumulations here will be on the light side. Went ahead and hoisted a Winter Storm Watch for the eastern mountains and Palmer Divide for Sunday night/Monday as a first guess, and suspect we'll need some advisories for lower elevation areas by the time accumulating snowfall ends late Mon, though will defer to later shifts for those. Max temps Mon will climb back above freezing at many lower elevation locations (below 7k feet), which will help lessen travel impacts by afternoon. Snow showers never completely end over the mountains Mon night into Tue, as next trough is already digging into the Great Basin by Tue morning. Expect precip with this system to slowly expand across the area during the day Tue, with a mix of low elevation rain and higher elevation snow into the evening. Upper low then sinks into AZ Tue evening, before moving eastward across the NM and the TX Panhandle Wed. This track should drag the heaviest precip south of the area overnight Tue, though snow showers will linger over the mountains and along the NM border for much of Wed as low slides by. Brief break between systems then expected Thu, before precip associated with still another upper level trough moves into the area from Fri into the weekend. Overall, stayed close to blended NBM guidance from Tue onward, as pattern looks favorable for fairly widespread and beneficial precipitation across much of the area the next several days. && .AVIATION...(For the 06Z TAFS through 06Z Sunday night) Issued at 1122 PM MDT Sat Mar 20 2021 Breezy conditions will be possible tonight at all taf sites as we could see some winds gusting to 25 mph at time at any of the taf sites. This is not explicitly shown in the TAFs as it is expected to be infrequent. For tomorrow, gusty SW winds will occur at KALS all afternoon becoming southeast in the evening with a chance of some showers. For KCOS and KPUB...gusty NNE winds will occur in the afternoon, with precip and lower cigs moving in after 00 UTC tomorrow. Some of the snow at KCOS could be on the heavier side tomorrow evening but temps will be relatively mild, so most signif accums will occur on the grassy areas. At KPUB, the precip will be rain in the evening going to snow later in the night. MVFR to IFR cigs are likely at KCOS and KPUB after 00 UTC tomorrow. && .PUB WATCHES/WARNINGS/ADVISORIES... Winter Storm Watch from Sunday evening through Monday afternoon for COZ072>075-079>082-084. && SHORT TERM...GARBEROGLIO LONG TERM...PETERSEN AVIATION...HODANISH
Hazardous Weather Outlook National Weather Service Pueblo CO 344 PM MDT Sat Mar 20 2021 COZ058>089-093>099-212145- Western Mosquito Range/East Lake County Above 11000 Feet- Leadville Vicinity/Lake County Below 11000 Feet- Eastern Sawatch Mountains Above 11000 Feet- Western Chaffee County Between 9000 and 11000 Feet- Central Chaffee County Below 9000 Feet- Western Mosquito Range/East Chaffee County Above 9000 Feet- Saguache County West of Continental Divide Below 10000 Feet- Saguache County East of Continental Divide Below 10000 Feet- La Garita Mountains Above 10000 Feet- Upper Rio Grande Valley/Eastern San Juan Mountains Below 10000 Feet-Eastern San Juan Mountains Above 10000 Feet- Del Norte Vicinity/Northern San Luis Valley Below 8500 Feet- Alamosa Vicinity/Central San Luis Valley Below 8500 Feet- Southern San Luis Valley- Northern Sangre de Cristo Mountains Between 8500 And 11000 Feet- Northern Sangre de Cristo Mountains Above 11000 Feet- Southern Sangre de Cristo Mountains Between 7500 and 11000 Feet- Southern Sangre de Cristo Mountains Above 11000 Feet- Northwestern Fremont County Above 8500 Feet- Western/Central Fremont County Below 8500 Feet- Wet Mountain Valley Below 8500 Feet- Wet Mountains between 6300 and 10000 Feet- Wet Mountains Above 10000 Feet- Teller County/Rampart Range Above 7500 Feet/Pikes Peak Between 7500 And 11000 Feet-Pikes Peak Above 11000 Feet- Canon City Vicinity/Eastern Fremont County- Northern El Paso County/Monument Ridge/Rampart Range Below 7500 Feet- Colorado Springs Vicinity/Southern El Paso County/Rampart Range Below 7400 Feet-Pueblo Vicinity/Pueblo County Below 6300 Feet- Walsenburg Vicinity/Upper Huerfano River Basin Below 7500 Feet- Trinidad Vicinity/Western Las Animas County Below 7500 Feet- Crowley County-La Junta Vicinity/Otero County- Eastern Las Animas County-Western Kiowa County- Eastern Kiowa County-Las Animas Vicinity/Bent County- Lamar Vicinity/Prowers County-Springfield Vicinity/Baca County- 344 PM MDT Sat Mar 20 2021 This hazardous weather outlook is for portions of central...east central...south central and southeast Colorado. .DAY ONE...This Afternoon and Tonight Strong southwesterly winds are expected across the mountain valleys and the plains this afternoon. Wind gusts ranging from 30 to 40 mph are expected, with locally higher values possible. Snow is expected to begin over the Continental Divide late this evening and into the morning spreading to the eastern mountains by Sunday morning. Light snow is possible over the upper Arkansas River Valley Sunday morning. .DAYS TWO THROUGH SEVEN...Sunday through Friday Snow will spread into the Continental Divide and Pikes Peak region Sunday with focus then shifting into all of the southeast mountains and adjacent plains Sunday night through Monday morning. The southeast mountains could pick up 6 to 12 inches of snow with locally higher amounts through this period, while the adjacent Palmer Divide could see 5 to 10 inches. Temperatures will not be as cold with this system which will allow for some melting to occur which will reduce accumulations across the lower elevations. Roads could briefly become slushy and snow covered, especially over northern El Paso county and down around the Walsenburg area Sunday night, but should melt off as snow lightens up and as temperatures warm above freezing again Monday morning. The southeast plains and valleys could see an inch or two of snow on grassy surfaces. Another storm system will bring the potential for additional light to moderate snowfall across southern Colorado Tuesday through early Wednesday. Focus for the heavier snowfall will be across the southern mountains including the eastern San Juans and southern Sangre De Cristo mountains this time. Another system will affect the region Friday into next weekend with additional light snow possible, mainly for the mountains. .SPOTTER INFORMATION STATEMENT... Weather spotters that meet reporting criteria for spotters will be possible tonight for the mountains and upper Arkansas River Valley for snow. GARBEROGLIO/10
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PUEBLO CO
116 AM MDT SUN MAR 21 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0100 AM NON-TSTM WND GST 6 S COLORADO CITY 37.86N 104.83W
03/21/2021 M67 MPH HUERFANO CO MESONET
MESONET STATION CO029 025S066 APACHE CITY.
&&The national radar mosaic for the moment the first event began.
4 winter storm, 1 high wind. Local standard time, as filed.
Apache City mesonet station.
Heavy snow of 10.4 inches. 4 miles south Air Force Academy.
Heavy snow of 10.0 inches. 2 miles north Black Forest.
Heavy snow of 9.0 inches. 5 miles northwest Cripple Creek.
Heavy snow of 8.5 inches. 4 miles west northwest Buena Vista.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2021Every state in 2021This day in weather historyWarnings in Colorado, March 2021
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: 952512, 952513, 952514, 952519, 952542.