Slow moving thunderstorms developed over the mountains, as the monsoon plume remained in place on this day. With the heavy rain that stemmed from these thunderstorms along with high antecedent soil moistures from rainfall over the past several days, the flash flood threat remained high with a few reports of flash flooding noted near the higher terrain.
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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.
Slow moving thunderstorms developed over the mountains, as the monsoon plume remained in place on this day. With the heavy rain that stemmed from these thunderstorms along with high antecedent soil moistures from rainfall over the past several days, the flash flood threat remained high with a few reports of flash flooding noted near the higher terrain.
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 Aug 2, 2:40 PM MST, 1 hour 32 minutes earlier.
Area Forecast Discussion National Weather Service Pueblo CO 340 PM MDT Mon Aug 2 2021 .SHORT TERM...(This evening through Tuesday) Issued at 340 PM MDT Mon Aug 2 2021 ...Heavy rainfall and potential for Flash Flooding increases in and near the mountains for Tuesday... Slow moving thunderstorms are blossoming over the mountains within the monsoon plume with 1 inch precipitable waters. With surface dew points in the 50s and better surface heating today, SPC mesoanalysis shows CAPE values of 500+ mlCAPES as of 1 PM...and could see this increase to around 1000 J/kg or slightly more with peak heating. Energy out west along the CO/UT border will be translating through the ridge increasing lift over the area, especially into tonight. Current flash flood watch still looks on target for the most part. With high antecedent soil moistures from rainfall over the past several days, the flash flood threat will remain high under the heavier rain cores, especially if these impact burn scars. flash flood watch runs now runs through Midnight to account for continued precipitation overnight ahead of the approaching disturbance. With the upper circulation moving through the ridge tonight and tomorrow, should see showers continue into the overnight hours across the mountains and spread into the I-25 corridor towards morning. Tuesday still looks like the higher risk day for flash flooding with the addition of better forcing. Mountains and the adjacent southern I-25 corridor look to be in the higher risk areas, though where the heaviest precipitation falls will be determined where the circulation center tracks. With precipitable waters still pushing around an inch+ across the mountains and adjacent plains, thunderstorms will be heavy rain producers and model soundings show the potential for up to 1000 J/kg of CAPE to support some embedded strong updrafts and locally heavy rainfall. Storms will be slow moving but should propagate slowly southeast through the evening and overnight hours. Will be hoisting another Flash Flood watch for Tuesday and include all of the mountains, valleys and southern I-25 corridor. Its possible some expansion into the I-25 corridor of El Paso and Pueblo counties will be necessary, especially if track of H7 circulation shifts northward a bit, but for now short range models put focus south of highway 50. Will let another set of high res model runs come in before adding more areas. Another tough call was to include the San Luis Valley. This will be more for the valley edges than valley floor but with the possibility of intense rainfall rates, can't rule out a flash flood risk even across the valley center. Rainfall rates of 1 to 3 inches per hour will be possible. Of course, burn scars carry the greatest risk as will urban areas from Walsenburg to Trinidad. -KT .LONG TERM...(Tuesday night through Monday) Issued at 340 PM MDT Mon Aug 2 2021 Tuesday night-Wednesday night...Latest models remain consistent of a weak vort lobe translating down the backside of ridge across the Rockies through the day Tuesday, which continues south across the southern Rockies through the day Wednesday. This enhanced area of uvv, along with strong solar heating and ample monsoonal moisture (PWATS 1 to 1.5 inches) in place all leads to widespread coverage of showers and thunderstorms over and near the higher terrain Tuesday afternoon, with scattered showers and isolated storms likely lingering into the early morning hours of Wednesday, especially along the eastern mountains and into the I-25 Corridor. Weak northerly steering flow aloft will keep the potential for heavy rainfall and flash flooding through Tuesday night, with current flash flood watch in place over and near the higher terrain through 12 am Wednesday. Latest models are also indicating mid level flow becoming more east to northeast Wednesday morning and into the afternoon, leading to more storm development across eastern mountains and plains, with the best coverage expected across southern Sangre de Cristo mountains, the southern I-25 Corridor and Raton Mesa, where we may need another flash flood watch for Wednesday. With the expected precipitation and associated cloud cover, highs on Wednesday look to be slightly below seasonal levels in the mid 70s to mid 80s across the lower elevations, and mainly in the 60s and 70s across the higher terrain. Thursday-Monday...Upper level ridging across the Great Basin and Intermountain West looks to flatten across the Rockies through the day Friday with increasing westerly flow aloft progged across the region through next weekend, as eastern Pacific energy translates across the Northern Tier. This will lead to a warming and drying trend across the Rockies at least through the early weekend. Longer range models do indicate the potential for another surge of subtropical moisture from the Desert SW later this weekend and into early next week, however they disagree on its placement. With that said, should see less coverage and intensity of storms through the end of the work week, with temperatures warming back to at and slightly above seasonal norms. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 340 PM MDT Mon Aug 2 2021 VFR conditions will be predominant throughout the forecast period for all TAF sites, CIGs will remain fairly high based although they could come down a bit in SHRA or TSRA in the vicinity of KALS throughout this evening and possibly later in this evening in the vicinity of KCOS. Precipitation could also reduce VIS temporarily into possibly MVFR or even IFR criteria in heavier showers and/or stronger storms if they do occur on station, and especially if flying further east over the mountainous areas. There will be a better chance of convection in the vicinity of all terminals towards the end of the forecast period for tomorrow afternoon and evening. Keep in mind that outflows can also cause sudden erratic wind shifts to occur at or in the vicinity of anyone of these terminals. Also be advised that with occasional surface winds becoming gusty, that there could be some light to moderate CAT near the surface in the vicinity of KALS and KCOS terminals for this evening. Winds at KALS will be primarily light and variable throughout the early part of the morning, and then increase out of the SW to W later later this afternoon, becoming strong and gusty at times up to 20 kts, they will then decrease in strength later in the evening and become light and variable throughout the morning, then become steady out of the NNE tomorrow afternoon. For KCOS and KPUB, winds will be primarily out of the SSE and ESE respectively and be could be gusty at times this afternoon up to 20 kt at KCOS. They will then weaken later during the morning and then increase tomorrow afternoon for both locations out of the NNW. -PS && .PUB WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch until midnight MDT tonight for COZ058>068- 072>080-087. Flash Flood Watch from Tuesday afternoon through Tuesday evening for COZ058>083-087-088. && SHORT TERM...KT LONG TERM...MW AVIATION...STEWARD
Hazardous Weather Outlook National Weather Service Pueblo CO 1153 AM MDT Mon Aug 2 2021 COZ058>089-093>099-031800- 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- 1153 AM MDT Mon Aug 2 2021 This hazardous weather outlook is for portions of central...east central...south central and southeast Colorado. .DAY ONE...This Afternoon and Tonight Slowly moving, and highly efficient rain producing, thunderstorms are expected to develop over and near the mountains this afternoon and evening. Flash flooding is possible, especially for areas with saturated soils, the Chalk Cliffs area, and the Spring, Junkins, Hayden Pass, and Decker burn scars. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday Flash flooding remains a good possibility Tuesday across the high terrain and portions of the I-25 corridor. Very wet antecedent conditions could pose issues across the region with passing showers and storms. .SPOTTER INFORMATION STATEMENT... Weather conditions that meet reporting criteria for spotters will be likely over and near the mountains this afternoon and tonight. 31/23
Special Weather Statement National Weather Service Pueblo CO 343 PM MDT Mon Aug 2 2021 COZ060>062-065-069-072-073-077-022230- Western/Central Fremont County Below 8500 Ft CO- Central Chaffee County Below 9000 Ft CO- Saguache County East of Continental Divide below 10000 Ft CO- Del Norte Vicinity/Northern San Luis Valley Below 8500 Ft CO- Western Chaffee County Between 9000 and 11000 Ft CO- Northern Sangre de Cristo Mountains Between 8500 And 11000 Ft CO- Northern Sangre de Cristo Mountains above 11000 Ft CO- Eastern Sawatch Mountains above 11000 Ft CO- 343 PM MDT Mon Aug 2 2021 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN CHAFFEE...WEST CENTRAL FREMONT AND NORTHEASTERN SAGUACHE COUNTIES UNTIL 430 PM MDT... At 342 PM MDT, Doppler radar was tracking a strong thunderstorm over Poncha Pass, with another storm near Decker Burn Scar, moving south at 10 mph. Winds in excess of 40 mph and torrential rainfall will be possible with this storm. If these storms stall too long, minor flooding with rock and mud flows will be possible on Poncha Pass. Locations impacted include... Decker Burn Scar and Poncha Pass. PRECAUTIONARY/PREPAREDNESS ACTIONS... Torrential rainfall is also occurring with this storm, and may lead to localized flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 3847 10619 3852 10596 3838 10588 3832 10617 TIME...MOT...LOC 2142Z 352DEG 9KT 3842 10608 KT
The Pueblo radar (KPUX), 158 km away, was scanning. The volume nearest the first event began at 23:11 UTC.
4 flash flood, 1 heavy rain. Local standard time, as filed.
Emergency management reported county roads 107 and 107A were flooded.
Scouring of gravel road surfaces, with deep trenches in some road ditches. Near by normally dry arroyo was bank full.
Emergency management reported that Highway 12 was overtopped with water.
Trained spotter reported road damage.
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, August 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: 983168, 983171, 983176, 983174, 983175.