Abundant monsoon moisture resulted in widespread showers and thunderstorms across eastern Utah. Even with a well-saturated profile, the stronger thunderstorms produced gusty winds in excess of 58 mph in addition to 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 resulted in widespread showers and thunderstorms across eastern Utah. Even with a well-saturated profile, the stronger thunderstorms produced gusty winds in excess of 58 mph in addition to heavy rain.
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 Aug 2, 2:00 PM MST, 2 hours 6 minutes earlier.
Area Forecast Discussion National Weather Service Grand Junction CO 300 PM MDT Wed Aug 2 2023 .SHORT TERM...(Tonight through Thursday night) Issued at 300 PM MDT Wed Aug 2 2023 As anticipated the waning monsoon moisture triggered terrain focused convection by late morning with some of this drifting off into nearby valleys. The full sun and moisture combined with slightly stronger winds aloft are also beginning to nudge storm mode from heavy rainers to hail producing storms. However all eyes are upstream in Utah and northern Arizona where convection is being driven by better synoptic conditions and storms have been well organized and should hold together in one or more clusters as the move into eastern Utah through the afternoon and across western Colorado through the evening and possibly early morning hours. Plenty of moisture remains for a heavy rain threat along with some storms containing larger hail. Winds will also be a threat as these cells take on a quasi-linear mode through the evening. The main plume of moisture has been pushed well back to the West were flooding has been a threat. Flooding will still be a threat with these clusters but storm motion will be increasing so it may take training or the right terrain and soil conditions. Conditions moving into Thursday look much quieter than the past few days as moisture looks to drop to more climatological normal and continue to fall into the end of the week. However there is another wave moving through with peak heating to provide large ascent and a weak surface boundary dropping into our northwest CWA. This should provide the focus for better storms while weaker isolated terrain based storms occur elsewhere. Temperatures will begin to respond to the drier air as well and push back to or above normal for Thursday afternoon. .LONG TERM...(Friday through Wednesday) Issued at 300 PM MDT Wed Aug 2 2023 By Friday, the high pressure has settled in to the Desert Southwest blocking any monsoonal moisture trying to move up out of Mexico. To the north, a longwave trough sits over Montana with a few shortwave systems cut off from jet support slowly moving through to the east. This pattern puts eastern Utah and Western Colorado under a dry zonal flow that pushes most of the convective activity east of the Divide, but residual moisture in the mountains will keep a chance for isolated showers and thunderstorms in the mountains each afternoon. This continues through Sunday before a deeper shortwave digs the longwave trough south along the Front Range, shifting the flow aloft to more northwesterly and bringing scattered afternoon showers and thunderstorms to the northern mountains into early next week. With the zonal flow aloft preventing any ridging over the region, look for temperatures to remain near normal through the extended period. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) Issued at 1150 AM MDT Wed Aug 2 2023 Thunderstorms are just getting started over the higher terrain late this morning. The storms will gradually move northward off the terrain into the valleys when they could impact TAF sites. Stronger more organized storms are forecast to move out of central Utah into our CWA by early evening with a complex of storms drifting eastward through the evening and early morning hours. So there will be periods of storms and this was attempted to be relayed in the forecasts. However things are likely to change and amendments will be issued as necessary. Gusty winds and brief heavy rainfall rates could drop conditions to ILS and possibly MVFR if a storm were to move over the airfield directly. KEGE did see some lower clouds due to precipitation and that is a probability for tomorrow morning as well. Otherwise VFR will prevail at areas outside of thunderstorm threats. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && SHORT TERM...15 LONG TERM...DB AVIATION...GJT
Hazardous Weather Outlook National Weather Service Grand Junction CO 239 AM MDT Wed Aug 2 2023 COZ001>014-017>023-UTZ022>025-027>029-030845- 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- 239 AM MDT Wed Aug 2 2023 This hazardous weather outlook is for eastern Utah and western Colorado. .DAY ONE...Today and Tonight Today will be the last day of truly monsoon like convection, with heavy rain and frequent lightning still the main threats, followed by small hail and gusty winds. Rainfall rates in excess of an inch an hour are possible. As with the last several days, activity will last well into the overnight. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday Drier air begins to work in on Thursday, decreasing shower and storm coverage somewhat. It will also lead to a transition away from heavy rain producing storms to storms more likely to produce gusty outflow winds. Frequent lightning remains a threat with any storm. Temperatures will also begin to slowly warm to near or a few degrees above normal by the weekend. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed.
Special Weather Statement
National Weather Service Grand Junction CO
333 PM MDT Wed Aug 2 2023
COZ017-020-UTZ028-022200-
Uncompahgre Plateau/Dallas Divide CO-
Paradox Valley/Lower Dolores River CO-La Sal and Abajo Mountains UT-
333 PM MDT Wed Aug 2 2023
...A strong thunderstorm will impact portions of west central Mesa
County through 400 PM MDT...
At 332 PM MDT, Doppler radar was tracking a strong thunderstorm 24
miles east of Castle Valley, moving north at 15 mph.
HAZARD...Winds in excess of 40 mph and nickel size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
This storm will remain over mainly rural areas of west central Mesa
County.
This includes Colorado 141 between mile markers 112 and 124.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 3866 10889 3871 10906 3894 10900 3887 10872
TIME...MOT...LOC 2132Z 202DEG 14KT 3875 10897
MAX HAIL SIZE...0.88 IN
MAX WIND GUST...40 MPH
KJSSpecial Weather Statement
National Weather Service Grand Junction CO
342 PM MDT Wed Aug 2 2023
UTZ024-022215-
Eastern Uinta Basin UT-
342 PM MDT Wed Aug 2 2023
...A strong thunderstorm will impact portions of central Uintah
County through 415 PM MDT...
At 341 PM MDT, Doppler radar was tracking a strong thunderstorm 19
miles southeast of Fort Duchesne, moving northeast at 15 mph.
HAZARD...Winds in excess of 40 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.
This storm will remain over mainly rural areas of central Uintah
County.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
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.
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 3993 10962 4003 10982 4030 10966 4015 10937
TIME...MOT...LOC 2141Z 213DEG 14KT 4005 10967
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH
DBSpecial Weather Statement
National Weather Service Grand Junction CO
413 PM MDT Wed Aug 2 2023
COZ006-017-022245-
Uncompahgre Plateau/Dallas Divide CO-Grand Valley CO-
413 PM MDT Wed Aug 2 2023
...A strong thunderstorm will impact portions of northwestern Mesa
County through 445 PM MDT...
At 413 PM MDT, Doppler radar was tracking a strong thunderstorm near
Fruita, or 9 miles west of Grand Junction, moving northeast at 15
mph.
HAZARD...Winds in excess of 40 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...
Grand Junction, Fruita, Glade Park, Redlands, Fruitvale and Orchard
Mesa.
This includes the following highways...
Interstate 70 in Colorado between mile markers 19 and 33.
U.S. Highway 50 in Colorado near mile marker 32.
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 3896 10875 3906 10888 3924 10867 3909 10848
TIME...MOT...LOC 2213Z 229DEG 14KT 3907 10874
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH
MDASpecial Weather Statement
National Weather Service Grand Junction CO
414 PM MDT Wed Aug 2 2023
UTZ029-022245-
Canyonlands/Natural Bridges UT-
414 PM MDT Wed Aug 2 2023
...A strong thunderstorm will impact portions of southwestern San
Juan County through 445 PM MDT...
At 414 PM MDT, Doppler radar was tracking a strong thunderstorm 10
miles east of Halls Crossing, moving northeast at 35 mph.
HAZARD...Wind gusts up to 50 mph and pea size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
This storm will remain over mainly rural areas of southwestern San
Juan County.
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 3745 11053 3753 11053 3769 11029 3739 11010
3732 11053 3737 11061 3745 11062
TIME...MOT...LOC 2214Z 234DEG 32KT 3743 11050
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH
ERWSpecial Weather Statement
National Weather Service Grand Junction CO
446 PM MDT Wed Aug 2 2023
COZ006-017-022315-
Uncompahgre Plateau/Dallas Divide CO-Grand Valley CO-
446 PM MDT Wed Aug 2 2023
...A strong thunderstorm will impact portions of northwestern Mesa
County through 515 PM MDT...
At 446 PM MDT, Doppler radar was tracking a strong thunderstorm near
Fruita, or 12 miles west of Grand Junction, moving north at 15 mph.
HAZARD...Winds in excess of 30 mph and pea size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
This strong thunderstorm will be near...
Fruita around 505 PM MDT.
This includes the following highways...
Interstate 70 in Colorado between mile markers 8 and 24.
Colorado 139 between mile markers 1 and 5.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
&&
LAT...LON 3906 10877 3909 10892 3927 10894 3924 10858
3911 10866
TIME...MOT...LOC 2246Z 202DEG 13KT 3913 10880
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...30 MPH
KJSPreliminary Local Storm Report
National Weather Service Grand Junction CO
459 PM MDT Wed Aug 2 2023
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0454 PM Hail 1 WNW Fruita 39.16N 108.75W
08/02/2023 M0.25 inch Mesa CO Trained Spotter
&&The Grand Junction radar (KGJX), 137 km away, was scanning. The volume nearest the first event began at 23:07 UTC.
1 thunderstorm wind. Local standard time, as filed.
A peak wind gust of 60 MPH was measured by the automated weather station at the Canyonlands Field Airport outside of Moab.
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, August 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: 1105496.