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.
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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 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 localized flash flooding and debris flows across portions of Mesa, Ouray and Gunnison counties.
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 25, 4:30 PM MST, 30 minutes earlier.
Area Forecast Discussion National Weather Service Grand Junction CO 530 PM MDT Sun Jul 25 2021 .SHORT TERM...(Tonight through Monday night) Issued at 206 PM MDT Sun Jul 25 2021 While an isolated shower or two continued into the morning hours, thunderstorm activity was slower to redevelop this afternoon in response to a broad swath of midlevel clouds over the central CWA. However, convection has blossomed within the last hour with cells beginning to produce lightning as well as rain rates of one to two inches per hour. Steering flow aloft remains light so the threat for localized flash flooding will continue through the evening hours before activity transitions to stratiform. As has been the trend over the last several days isolated showers will continue overnight, favoring the southern zones in response to the influence of the departing retrograding low. Monday will see the center of the upper level ridge slowly transition eastward and resettle over the CWA. PWATs will trim back slightly across the northern tier of the forecast area resulting in less storm coverage. Even so, PWATs will trend near an inch in southwest Colorado with CAM guidance projecting numerous showers and thunderstorms over the southern and central Colorado mountains during the afternoon. The similar threats of lightning, heavy rain and localized flooding can once again be expected through Monday evening. .LONG TERM...(Tuesday through Sunday) Issued at 206 PM MDT Sun Jul 25 2021 On Tuesday, the high pressure aloft will become centered over the Central Plains placing our area under weak south-southeast flow. This is a favorable pattern for monsoon moisture to advect into the CWA, and as a result widespread storms and the potential for heavy rainfall will exist. The high pressure is expected to drift over the Central and Southern Plains, but overall this shouldn't affect the sensible weather through next weekend. There are hints in the models that a remnant tropical low pressure from Mexico may get absorbed into the flow around the high later in the week. This could enhance or hinder convection depending on the timing and where it tracks over the region. Although the general trend is that precipitation coverage increases due to the remnant low. The consensus is for the low to get steered towards the Four Corners and or Great Basin. One thing different from this current high placement is that next week convectively induced waves may form upstream (NM/AZ) and move over our area overnight. This means nocturnal storms may be better supported. The latest ensemble means in the 8 to 10 day period maintains ridging placed over the Northern Rockies, with the midlevel high centered over the Texas Panhandle. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 530 PM MDT Sun Jul 25 2021 Evening storms may produce heavy rainfall and lightning at most TAF sites except KVEL and KHDN where a slightly drier airmass is in place. VFR should prevail with temporary MVFR conditions possible if a shower directly impacts the airfield. Expect similar weather to play out from late Monday morning through the afternoon. && .HYDROLOGY... Issued at 206 PM MDT Sun Jul 25 2021 The threat of heavy rainfall still exists with above normal moisture remaining in the area. This will lead to localized flooding today due to slow storm motion and the possibility of training storms. Similar conditions are expected into the new week. The most vulnerable areas will be burn scars and areas which have received heavy rainfall the past few days and have already experienced flooding or debris flows. The potential for more widespread flooding returns by mid next week as the high drifts towards the southern Plains, advecting additional pulses of monsoonal moisture into the region. Please continue to remain up- to-date on the latest forecast, particularly if travelling. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...Flash Flood Watch until 8 PM MDT this evening for COZ008-010-013. UT...None. && SHORT TERM...MMS LONG TERM...KJS AVIATION...TGJT HYDROLOGY...TGJT
Hazardous Weather Outlook National Weather Service Grand Junction CO 528 AM MDT Sun Jul 25 2021 COZ001>014-017>023-UTZ022>025-027>029-261130- 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- 528 AM MDT Sun Jul 25 2021 This hazardous weather outlook is for eastern Utah and western Colorado. .DAY ONE...Today and Tonight Thunderstorm development will occur today especially over the mountains by early afternoon. Lightning will be the main threat along with gusty outflow winds. A few storms will be capable of producing locally heavy rainfall which could lead to flooding. Thunderstorms should dissipate by the early morning hours. .DAYS TWO THROUGH SEVEN...Monday through Saturday Daily scattered to numerous showers and thunderstorms can be expected each day with monsoon moisture entrenched across the area. Moderate to heavy rain and gusty winds will be the primary threats with storms along with lightning. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
310 PM MDT SUN JUL 25 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0430 PM FLASH FLOOD 11 NNE PARADOX 38.52N 108.89W
07/24/2021 MESA CO PUBLIC
NORMALLY DRY ARROYO ERUPTED INTO A RAGING
WATERFALL. MUD AND DEBRIS FLOWED ON TO
HIGHWAY 141. WATERFALL SHARED ON SOCIAL
MEDIA.
&&Special Weather Statement National Weather Service Grand Junction CO 453 PM MDT Sun Jul 25 2021 COZ002-003-252315- Roan and Tavaputs Plateaus CO-Central Yampa River Basin CO- 453 PM MDT Sun Jul 25 2021 ...SPECIAL WEATHER STATEMENT... At 452 PM MDT, Doppler radar was tracking a strong thunderstorm 24 miles northwest of Parachute, or 49 miles north of Grand Junction. This storm was nearly stationary. Half inch hail and winds in excess of 30 mph will be possible with this storm. This storm will remain over mainly rural areas of south central Rio Blanco County. LAT...LON 3980 10819 3969 10818 3967 10834 3981 10835 TIME...MOT...LOC 2252Z 072DEG 2KT 3976 10826 KJS
Special Weather Statement National Weather Service Grand Junction CO 520 PM MDT Sun Jul 25 2021 COZ001>003-260000- Roan and Tavaputs Plateaus CO-Lower Yampa River Basin CO- Central Yampa River Basin CO- 520 PM MDT Sun Jul 25 2021 ...SPECIAL WEATHER STATEMENT... At 520 PM MDT, Doppler radar was tracking a strong thunderstorm 24 miles northwest of Parachute, or 44 miles north of Grand Junction, moving southwest at 15 mph. Half inch hail and winds in excess of 30 mph will be possible with this storm. This storm will remain over mainly rural areas of central Garfield and south central Rio Blanco Counties. 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. && LAT...LON 3982 10827 3970 10819 3954 10847 3974 10859 TIME...MOT...LOC 2320Z 062DEG 12KT 3971 10837 KJS
The Grand Junction radar (KGJX), 102 km away, was scanning. The volume nearest the first event began at 00:03 UTC.
3 debris flow, 1 flash flood. Local standard time, as filed.
Numerous mud and rockslides occurred near Emerald Lake at the end of Gothic Road. Some slides were smaller than others but the biggest was reported to be about 6 feet deep.
A debris flow occurred along Interstate 70 between mile markers 42 and 47 as a result of heavy rains. The road was closed for a couple of hours due to cleanup operations.
A mudslide occurred as a result of heavy rains across Colorado Highway 550 near Ironton (mile marker 85). The mudslide covered both directions of the highway.
Mesa County Sheriff's Office responded to a report of two hikers trapped by flash flood waters in Rough Canyon. When deputies arrived at the trailhead, it was discovered several other people were also unable to reach the parking lot due to rising floodwaters. Storms in the area quickly turned what typically is a dried creek bed at the start of the trail into an unpassable rushing river. Rescue crews estimate it was about 15 feet wide and 3-5 feet deep. It took about 6 hours for the water to recede enough for rescuers to reach everyone. Four families, who started the day on a hike or UTV trail, were safely rescued.
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: 965683, 965346, 965812, 965679.