After high pressure dominated eastern Utah for a couple of days, moisture gradually increased ahead of an approaching system. This led to the development of isolated to scattered high-based thunderstorms.
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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.
After high pressure dominated eastern Utah for a couple of days, moisture gradually increased ahead of an approaching system. This led to the development of isolated to scattered high-based thunderstorms. Given the dry air at the lower levels, gusty outflow winds were the primary threat from storms. The stronger storms produced gusty winds in excess of 58 mph across Uintah County.
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 26, 10:17 AM MST, 4 hours 3 minutes earlier.
Area Forecast Discussion National Weather Service Grand Junction CO 1117 AM MDT Wed Jul 26 2023 .SHORT TERM...(Today through Thursday) Issued at 243 AM MDT Wed Jul 26 2023 High pressure is currently centered over eastern New Mexico placing us under southwest flow. Within in this flow moisture increases slightly so expect another round of showers and storms this afternoon and evening. Initially the convection will form over the higher terrain and create outflows in the process. These outflows will force convection to spread over the adjacent valleys. They may also produce wind gusts of 30-50 mph. We have yet to get rid of the thermal bubble in place therefore expect highs similar to yesterday. PWATs will exceed 0.75 inches in spots, but in general the highest values reside in the plume that will be concentrated over the northern two thirds of the forecast area. This is where the coverage of convection will be greatest, and where brief moderate to heavy rainfall is possible. Mainly in the higher terrain. With steering flow around 15-20 kt and outflow propagation storms will be on the move limiting the residence time. Further south the coverage looks to be more isolated to scattered with the least activity near the Four Corners. Most of the convection diminishes in the late evening. Tomorrow a trough over the Pacific Northwest causes the ridge to flatten, which allows moisture to fill in across the remainder of the forecast area. As a result the coverage of convection increases across the southern third especially in and around the San Juans. Similarly the chances for moderate to heavy rainfall are equal for most the higher terrain. Temperatures do not change much so expect the gusty outflows. Convection should again propagate over the adjacent valleys in the late afternoon and evening hours with most of the activity diminished by midnight. .LONG TERM...(Thursday night through Tuesday) Issued at 243 AM MDT Wed Jul 26 2023 The models show good agreement on the synoptic pattern Friday with the high centered over western New Mexico and a deep low descending into the Pacific Northwest. By Saturday, the low turns the corner and slowly starts climbing the ridge into British Columbia Sunday, tracking over central Alberta Monday and over central Saskatchewan and Manitoba Tuesday. As this low turns the corner, a shortwave trough rotating into the base of the low digs into Northern California and plows into the ridge Sunday with enough umph to dislodge the high starting the high's eastward trek. By Sunday afternoon, it is east of the front range moving onto the Plains. The GFS is the more progressive with this shortwave, with a deeper trough, and leads the European and Canadian models by six to 12 hours. Otherwise the models maintain the good agreement. Leaning towards the GFS solution base on recent past performance where the other models tend to eventually come in line with the GFS. A second shortwave Monday pushes the high eastward over Oklahoma-Kansas. Yet a third shortwave Tuesday descends into the Pacific Northwest to continue to nudge the high farther east with general troughing off the Pacific Coast. Once the high slides east of the Divide, the door opens to the south to deep monsoonal moisture out of the Gulf of California and over the Sonoran Desert. An inverted trough moving west under the high reaches the Desert Southwest Sunday to help pull the moisture north into Arizona and provides energy for convection. The models indicate a series of inverted troughs rotating around the high into the region Monday and Tuesday with dynamics to aid convection. By Wednesday, the high has moved far enough to the east that the western States will be under a southwest flow pulling continued moisture up into eastern Utah and Western Colorado. This is looking like a solid monsoonal flow that may last a week or more. Based on the synoptic picture above, look for isolated showers and thunderstorm to diminish Thursday evening leaving quiet weather overnight. Dry air moving in from the west over the region will limit afternoon convection to the San Juan Mountains and along the Divide where residual moisture and diurnal heating will support isolated to scattered showers and thunderstorms. Saturday will see an uptick in activity as the moist plume moves into the southern Mountains over the San Juan Mountains and even pushing north into the West Elk and Elk Mountains with the high sliding east of the Divide. As the door opens to the south, the deep moisture will push north to the I-70 corridor Sunday with widespread thunderstorms over the central and southern mountains, and scattered thunderstorms in the lower valleys and over the Flat Tops. As this moisture moves into the region, the southerly flow will be weak, leading to slow moving and training storms with increased risks for localized flash flooding. This will be something to watch for. With the deeper moisture, showers will continue through the evening and into the overnight. By Monday, the moist plume will have pushed north into Wyoming bringing scattered to widespread afternoon and evening showers and thunderstorms across eastern Utah and Western Colorado. This activity looks to continue daily through mid next week. Until the moisture moves in from the southwest, temperatures will remain five to ten degrees above normal. With the monsoonal swamp cooler turned on, temperatures will drop to near normal by Monday and may even fall a few degrees below normal Tuesday and Wednesday. Changes are on the way. Stay tuned for the latest updates on this forecast. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) Issued at 1115 AM MDT Wed Jul 26 2023 VFR conditions will prevail for the next 24 hours. Showers and thunderstorms will form along the higher terrain, especially along and north of the I-70 corridor, this afternoon and evening. Included VCTS in several TAFs to account for this. Areas that don't see shower or storm activity can expect typical diurnally driven gusty winds this afternoon. All activity should begin to diminish after sunset with winds becoming light. FEW to SCT mid to high level clouds expected through the period. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && SHORT TERM...KJS LONG TERM...DB AVIATION...TGJT
Hazardous Weather Outlook National Weather Service Grand Junction CO 336 AM MDT Wed Jul 26 2023 COZ001>014-017>023-UTZ022>025-027>029-270945- 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- 336 AM MDT Wed Jul 26 2023 This Hazardous Weather Outlook is for northwest Colorado, southwest Colorado, west central Colorado, east central Utah, northeast Utah and southeast Utah. .DAY ONE...Tonight. Isolated to scattered showers and thunderstorms are possible today. Strong outflow winds with gusts upwards of 40 to 60 mph and lightning pose the greatest threat with these storms. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. The potential for thunderstorms continues through the next several days, favoring more the southern mountains going into the weekend. Gusty outflow winds and lightning will remain the main threats with any activity. Storm coverage is expected to increase Sunday into early next week as deeper moisture moves into the region. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
Special Weather Statement
National Weather Service Grand Junction CO
1237 PM MDT Wed Jul 26 2023
COZ002-003-013-261900-
Roan and Tavaputs Plateaus CO-Flat Tops CO-
Central Yampa River Basin CO-
1237 PM MDT Wed Jul 26 2023
...A strong thunderstorm will impact portions of northeastern Rio
Blanco County through 100 PM MDT...
At 1237 PM MDT, Doppler radar was tracking a strong thunderstorm near
Meeker, or 39 miles northwest of Glenwood Springs, moving east at 25
mph.
HAZARD...Wind gusts up to 50 mph and half inch hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Meeker and Buford.
This includes Colorado 13 between mile markers 41 and 44.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
&&
LAT...LON 3984 10786 4003 10794 4020 10753 3994 10740
TIME...MOT...LOC 1837Z 248DEG 22KT 3997 10781
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...50 MPH
MDASpecial Weather Statement
National Weather Service Grand Junction CO
215 PM MDT Wed Jul 26 2023
COZ008-010-013-262045-
Central Colorado River Basin CO-Flat Tops CO-
Gore and Elk Mountains/Central Mountain Valleys CO-
215 PM MDT Wed Jul 26 2023
...A strong thunderstorm will impact portions of west central Eagle
and east central Garfield Counties through 245 PM MDT...
At 215 PM MDT, Doppler radar was tracking a strong thunderstorm 10
miles east of Glenwood Springs, moving northeast at 20 mph.
HAZARD...Wind gusts up to 50 mph and half inch hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Gypsum, Dotsero, Shoshone and Sweetwater.
This includes Interstate 70 in Colorado between mile markers 123 and
144.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
&&
LAT...LON 3950 10718 3960 10727 3977 10697 3958 10681
TIME...MOT...LOC 2015Z 238DEG 16KT 3960 10715
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...50 MPH
MDAThe Grand Junction radar (KGJX), 191 km away, was scanning. The volume nearest the first event began at 21:19 UTC.
2 thunderstorm wind. Local standard time, as filed.
A peak wind gust of 59 MPH was measured by the automated weather station at Asphalt Ridge, 3 miles southwest of Vernal.
A peak wind gust of 68 MPH was measured by the automated weather station at the Vernal Regional Airport.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2023Every state in 2023This day in weather historyWarnings in Utah, July 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: 1104620, 1104619.