Abundant monsoon moisture remained in place across the Western Slope. As a result, another round of widespread showers and thunderstorms developed across the area with many storms producing heavy rain.
Every event with a place to put it. 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 GJT wrote it up.
Abundant monsoon moisture remained in place across the Western Slope. As a result, another round of widespread showers and thunderstorms developed across the area with many storms producing heavy rain. This led to several reports of flash flooding and debris flows across portions of west-central and southwest Colorado. Additionally, severe thunderstorms produced large hail in Norwood.
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 Grand Junction, CO wrote its last area forecast discussion before the first event at Jul 24, 10:42 AM MST, 35 minutes earlier.
Area Forecast Discussion National Weather Service Grand Junction CO 1142 AM MDT Sat Jul 24 2021 .SHORT TERM...(Today through Sunday) Issued at 503 AM MDT Sat Jul 24 2021 It appears the ingredients are in place for the threat of localized flash flooding across portions of southern Colorado into far southeast Utah today. While drier air will be filtering into the far northern CWA behind a trough moving into the northern High Plains...abundant monsoonal moisture remains entrenched across the 4 Corners region. Water vapor shows a low sitting over central New Mexico this morning which will be retrograding westward into the Desert Southwest over the next 24 hours. This anomalous pattern will also set up an irregular easterly flow pattern across our CWA today with storm motion to the West-Southwest. Ascent from the low to our South combined with an increase in shear aloft lead to slightly better storm organization this afternoon. Storms will initiate over the higher terrain of the central and southern mountains by mid-day then take on that westerly drift. CAPE values should creep up above 1500j/kg in the lower valleys where dewpoints should be in the mid 50s. Though storm motion may be a bit faster than the past few days these storms will have stronger updrafts and be able to produce heavier precipitation including small hail. The HiRes CAM models do favor the strongest storms coming off the San Juans and surviving into portions of southeast Utah. This is where the highest concern is for localized flash flooding. Burn scars and terrain will be of concern in the mountains as well as saturated soil conditions back into southern Gunnison County. Farther north the deformation zone will also lead to thunderstorm activity though this is where weaker shear is located. The Grizzly Creek burn scar missed out on the heavier precipitation yesterday and if all pans out it should again today with most of the action to the South. The low will make it into Arizona by early Sunday and high pressure over the Intermountain West will begin to merge high pressure over the Southern Plains. There will be a col centered over our CWA during this transition with weak ascent and flow aloft. With no flushing out of moisture afternoon storms will once again fire over the terrain. Localized flooding will continue to be a threat with slow storm motions and a pattern favorable for training storms. .LONG TERM...(Sunday night through Friday) Issued at 503 AM MDT Sat Jul 24 2021 After the high pressure cells merge the rejuvenated SubTrop high will settle over the Central Plains through all of next week. This will keep the monsoonal tap going in full swing. The main plume however appears to be mainly to our West through midweek before it rotates back around the high. It would appear mainly the terrain will favored with residual moisture leading to afternoon thunderstorms through Wednesday...then as more moisture arrives late in the week the storms and heavy rainfall threat will become more widespread. && .AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon) Issued at 1133 AM MDT Sat Jul 24 2021 Lightning was already detected with cells west of ASE. Expect this activity to rapidly expand within the next hour as diurnally driven storms intensify over higher terrain in this moist and unstable environment. Storms will have better storm motion, generally driving in a westward direction. In addition, coverage will favor TAF sites along and south of the I-70 corridor. Best confidence of TSRA is placed over mountain terminals, including TEX and ASE. However, VCTS conditions are possible at all terminals (excluding HDN and VEL) this afternoon. VFR conditions will generally prevail, however, temporary MVFR conditions are possible if a thunderstorm directly impacts a terminal. Light precipitation may linger overnight, though potential for VCTS dwindles after 03Z. && .HYDROLOGY... Issued at 503 AM MDT Sat Jul 24 2021 Thunderstorms with the potential to produce heavy rainfall will be a threat across southern portions of Colorado and southeast Utah today. Also several areas have received significant precipitation the past few days in this region and prompted a Flash Flood Watch for today. Burn scars and terrain favored for fast runoff responses in heavy rainfall rates will be especially vulnerable to flash flooding today. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...Flash Flood Watch until 9 PM MDT this evening for COZ014-017>021. UT...Flash Flood Watch until 9 PM MDT this evening for UTZ022-028. && SHORT TERM...15 LONG TERM...ERW AVIATION...ERW HYDROLOGY...15
Hazardous Weather Outlook National Weather Service Grand Junction CO 549 AM MDT Sat Jul 24 2021 COZ001>014-017>023-UTZ022>025-027>029-251200- Lower Yampa River Basin-Central Yampa River Basin- Roan and Tavaputs Plateaus-Elkhead and Park Mountains- Upper Yampa River Basin-Grand Valley-Debeque to Silt Corridor- Central Colorado River Basin-Grand and Battlement Mesas- Gore and Elk Mountains/Central Mountain Valleys- Central Gunnison and Uncompahgre River Basin- West Elk and Sawatch Mountains-Flat Tops- Upper Gunnison River Valley-Uncompahgre Plateau and Dallas Divide- Northwest San Juan Mountains-Southwest San Juan Mountains- Paradox Valley/Lower Dolores River- Four Corners/Upper Dolores River-Animas River Basin- San Juan River Basin-Southeast Utah-Eastern Uinta Mountains- Eastern Uinta Basin-Tavaputs Plateau-Arches/Grand Flat- La Sal and Abajo Mountains-Canyonlands/Natural Bridges- 549 AM MDT Sat Jul 24 2021 This hazardous weather outlook is for eastern Utah and western Colorado. .DAY ONE...Today and Tonight Thunderstorm development will occur again by mid-day over the mountains with storms moving southwest into the adjacent valleys of the southern Colorado and Utah. Gusty winds...small hail and heavy rainfall will be threats with storms in the south today. With monsoonal moisture in place...localized flooding is also a concern with some storms and a Flash Flood Watch is in effect for southern portions of Utah and Colorado. Storms this evening will stratify out and linger through the early morning hours as light showers. .DAYS TWO THROUGH SEVEN...Sunday through Friday Daily scattered to numerous showers and thunderstorms can be expected from Sunday onward. Moderate to heavy rain and gusty winds will be the primary threats with storms along with lightning. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected today or tonight, however spotters are encouraged to relay rainfall amounts or any observed flooding to the National Weather Service in Grand Junction.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1031 AM MDT SAT JUL 24 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1030 AM HEAVY RAIN LAKE CITY 38.03N 107.31W
07/24/2021 M1.23 INCH HINSDALE CO PUBLIC
24-HOUR RAINFALL.
&&
KJSPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1037 AM MDT SAT JUL 24 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0716 AM HEAVY RAIN 2 ENE RICO 37.70N 108.00W
07/24/2021 M1.31 INCH DOLORES CO MESONET
MESONET STATION EW6434 RICO.
0700 AM HEAVY RAIN 2 NNE LAKE CITY 38.05N 107.30W
07/24/2021 M1.23 INCH HINSDALE CO CO-OP OBSERVER
CO-OP OBSERVER STATION LCIC2 LAKE CITY 1
NNE.
0700 AM HEAVY RAIN SILVERTON 37.81N 107.67W
07/24/2021 M1.01 INCH SAN JUAN CO COCORAHS
COCORAHS STATION CO-SJ-4 SILVERTON.
0645 AM HEAVY RAIN 10 SW MAHER 38.54N 107.69W
07/24/2021 M0.92 INCH MONTROSE CO MESONET
MESONET STATION MTSC2 BLACK CANYON MONTROSE
11 ENE CO US.
0716 AM HEAVY RAIN 10 W TENNESSEE PASS 39.38N 106.50W
07/24/2021 M0.92 INCH EAGLE CO MESONET
MESONET STATION EW6190 SUMMIT COUNTY.
0710 AM HEAVY RAIN 6 NNE FALFA 37.28N 107.72W
07/24/2021 M0.85 INCH LA PLATA CO MESONET
MESONET STATION FW8982 DURANGO.
0700 AM HEAVY RAIN 1 SW PITKIN 38.60N 106.53W
07/24/2021 M0.82 INCH GUNNISON CO COCORAHS
COCORAHS STATION CO-GN-59 PITKIN 1.1SW.
0700 AM HEAVY RAIN 5 NW OLATHE 38.65N 108.06W
07/24/2021 M0.79 INCH MONTROSE CO COCORAHS
COCORAHS STATION CO-MT-60 OLATHE 5.2 NW.
0700 AM HEAVY RAIN 3 NW LAZEAR 38.81N 107.81W
07/24/2021 M0.75 INCH DELTA CO COCORAHS
COCORAHS STATION CO-DL-49 LAZEAR 3NW.
0800 AM HEAVY RAIN 2 SSW PAGOSA SPRINGS 37.25N 107.03W
07/24/2021 M0.75 INCH ARCHULETA CO COCORAHS
COCORAHS STATION CO-AU-26 PAGOSA SPRINGS
1.6SSW.
1000 AM HEAVY RAIN 4 SSE PAGOSA SPRINGS 37.21N 106.98W
07/24/2021 M0.72 INCH ARCHULETA CO COCORAHS
COCORAHS STATION CO-AU-43 PAGOSA SPRINGS 4.5
SSE.
0700 AM HEAVY RAIN 6 NW OLATHE 38.66N 108.06W
07/24/2021 M0.71 INCH MONTROSE CO COCORAHS
COCORAHS STATION CO-MT-58 DELTA 5.9 S.
0500 AM HEAVY RAIN 3 SSW COAL BANK PASS 37.66N 107.80W
07/24/2021 M0.60 INCH SAN JUAN CO MESONET
MESONET STATION CADC2 3.3 SW COAL BANK PASS
(SNOTEL).
0700 AM HEAVY RAIN 4 NNW LAZEAR 38.84N 107.80W
07/24/2021 M0.56 INCH DELTA CO COCORAHS
COCORAHS STATION CO-DL-22 HOTCHKISS 5.1WNW.
0700 AM HEAVY RAIN 7 N ROCKWOOD 37.60N 107.78W
07/24/2021 M0.56 INCH LA PLATA CO MESONET
MESONET STATION ATTC2 6.9 N ROCKWOOD.
0709 AM HEAVY RAIN 3 NW LAZEAR 38.82N 107.81W
07/24/2021 M0.55 INCH DELTA CO CO-OP OBSERVER
CO-OP OBSERVER STATION HCHC2 HOTCHKISS 5WNW.
0709 AM HEAVY RAIN 6 SW IGNACIO 37.06N 107.71W
07/24/2021 M0.53 INCH LA PLATA CO MESONET
MESONET STATION MMRC2 MESA MTN, IGNACIO 5SW.
&&Special Weather Statement National Weather Service Grand Junction CO 1157 AM MDT Sat Jul 24 2021 COZ009-010-012-241845- Grand and Battlement Mesas CO- Gore and Elk Mountains/Central Mountain Valleys CO- West Elk and Sawatch Mountains CO- 1157 AM MDT Sat Jul 24 2021 ...SPECIAL WEATHER STATEMENT... At 1156 AM MDT, Doppler radar was tracking a strong thunderstorm 13 miles northwest of Marble, or 25 miles south of Glenwood Springs, moving northwest at 15 mph. Pea size hail and winds in excess of 30 mph will be possible with this storm. This storm will remain over mainly rural areas of west central Pitkin and northeastern Mesa Counties. This includes Colorado 133 near mile marker 40. PRECAUTIONARY/PREPAREDNESS ACTIONS... Heavy rainfall is also occurring with this storm, and may lead to localized flooding. Do not drive your vehicle through flooded roadways. This storm may intensify, so be certain to monitor local radio stations and available television stations for additional information and possible warnings from the National Weather Service. && LAT...LON 3920 10728 3912 10733 3924 10778 3940 10763 TIME...MOT...LOC 1756Z 119DEG 15KT 3918 10739 JDC
The Grand Junction radar (KGJX), 85 km away, was scanning. The volume nearest the first event began at 18:13 UTC.
8 debris flow, 1 hail. Local standard time, as filed.
A debris flow of mud, rocks and trees occurred along Colorado Highway 133 north of Redstone as a result of heavy rains. The road was closed for several hours due to cleanup operations.
Rocks, mud and water were found along Main Street in Collbran as a result of heavy rains. Sandbags were placed in front of certain businesses. Additionally, two trees were uprooted due to flash flooding along Highway 330.
A debris flow of mud and rocks occurred along Colorado Highway 145 in Norwood Hill as a result of heavy rains. The road was closed for several hours due to cleanup operations.
A debris flow occurred along Colorado Highway 141 between mile markers 69 through 79 as a result of heavy rains. The road was closed for several hours due to cleanup operations.
San Miguel Sheriff reported that Sanborn Park Road was impassable and closed due to mudslides from heavy rain.
A normally dry arroyo erupted into a raging waterfall along Colorado Highway 141. Additionally, mud and debris flowed onto the highway.
Heavy rains led to a debris flow across sections of First Fork Road on the Pagosa Ranger District. Portions of the road were washed out. The exact time of the slide is unknown and was estimated based on surrounding observations.
Dime to quarter-sized hail accumulated in a yard on the east side of Norwood.
Colorado Highway 141 was closed in both directions for several hours due to a mudslide that occurred between 4.40 Road near Gateway and Desert Road in Unaweep Canyon.
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, July 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: 965337, 965342, 965338, 965339, 965678, 965343, 965816, 965340, 965341.