Plenty of residual monsoon moisture remained over southwest Colorado which resulted in another day of showers and thunderstorms across the region. Storms were slow moving and produced 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.
Plenty of residual monsoon moisture remained over southwest Colorado which resulted in another day of showers and thunderstorms across the region. Storms were slow moving and produced heavy rain. Localized flash flooding occurred in Hinsdale 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 Aug 3, 1:53 PM MST, 2 hours 7 minutes earlier.
Area Forecast Discussion National Weather Service Grand Junction CO 253 PM MDT Wed Aug 3 2022 .SHORT TERM...(Tonight through Thursday night) Issued at 158 PM MDT Wed Aug 3 2022 High pressure is currently centered just south of the Four Corners. PWAT values still indicate sufficient moisture for afternoon convection. Looking more into the details...the morning sounding indicated moist adiabatic lapse rates through the mid levels and slight drying aloft. Model soundings show this drying is more pronounced north of I-70 with very little changes down south. Convection has already fired over the higher terrain down there. Subsidence in proximity to the high and the associated cap will limit the storm coverage across the north. The orographic ascent and sufficient moisture south of I-70 will support additional development through the afternoon. The subsidence and midlevel cap will make it difficult for storms to leave the higher terrain. If cold pools are able to form they will help some storms to drift into the adjacent valleys especially around the San Juans. Slower storm motions, nearby cell propagation and above normal PWATs keep the heavy rainfall potential in play, but flooding should stay localized. Outflow winds could also materialize near the stronger clusters of convection, but anything over 40 mph will be limited. Beside residual outflows most of the convection should come to an end this evening, so expect mainly a quiet overnight. Tonight and into tomorrow the high pressure shifts slightly eastward, therefore less subsidence should allow for a slight increase in storm coverage. The soundings still show that midlevel cap/dry layer in place especially north. Some of that may even mix into the lower deserts so high temperatures come up a few degrees. Like today expecting the higher chances for storms south of I-70 with more isolated coverage to the north. Heavy rainfall and outflows are possible similar to today. Several high-res models are indicating the potential for a convective induced wave to form in NM and move into our area in the evening/overnight hours. If this occurred convection could linger past sunset in the Four Corners region. With the high gradually drifting eastward the tap into deeper moisture opens up and as a result PWATs increase overnight. This could also help sustain the later convection as well. .LONG TERM...(Friday through Wednesday) Issued at 158 PM MDT Wed Aug 3 2022 Deterministic models paint a vast reservoir of precipitable water camped out over Nevada, northern Utah, southern Idaho and Wyoming on Friday. Widespread values of 200% of normal reside within this area. The richest portion of that plume will cover much of the northern half of our CWA, roughly north of I-70. South of I-70, things are a meager 140% of normal. Here on the arid West Slope, it's all relative. Needless to say, our monsoonal pattern is still alive. Models are also bringing a west coast trough of low pressure ashore in some capacity with a right entrance jet streak setting up over northeast Utah. With all this moisture and some upper level dynamics thrown in, it looks like Friday afternoon will provide another round of mountain convection and likely some showers for the valleys as well. A vague repeat of Friday's pattern lingers through Saturday with models holding onto a cutoff low situated off the coast of NORCAL. This setup will likely encourage shortwave pulses to pass through the CWA again Saturday and thereby initiate more convection. Model resolution makes these sort of events a challenge to pinpoint problem areas. Suffice to say that Saturday will shape up as another active weather day with high terrain being favored for development. Storm motions will likely be more vigorous, avoiding the slow drift we've seen under high pressure the past few weeks. By Sunday, models are diverging in their solutions. Differences arise with the waves ejecting out of the cutoff low still sitting offshore in the Pacific. EC drags a more robust wave across the northern Rockies, while GFS flattens out into a milder zonal flow pattern. Presently, a reasonable expectation is for terrain driven convection in this mostly westerly zonal flow. Models try to merge back together Monday with the cutoff low still lingering offshore and high pressure building back in. The biggest uncertainty for Monday and beyond will be the placement of the high and what it allows for in terms of tropical moisture advection. Temperatures will begin to warm again Monday under this high pressure regime, following a cooling trend over the weekend. If you're still following this convoluted tale of long term model outputs, model confidence is pretty low by now. It appears that a high amplitude ridge builds in across the Rockies Tuesday and Wednesday. Storm track and moisture advection are still contingent on the high's placement. Remnant surface moisture and persistent returns of monsoonal flow will ensure the threat remains for hydrological concerns around burn scars, arroyos, and small streams over the next week. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) Issued at 1141 AM MDT Wed Aug 3 2022 Most terminals will remain under high pressure VFR conditions today with light winds and scattered mid and high clouds. Isolated showers and thunderstorms will develop over high terrain this afternoon. KTEX, KASE, and KGUC will see the best chances for thunderstorms today. Storms will be capable of producing gusty outflows and small hail then diminish after sunset. VFR conditions will prevail overnight to close the period. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && SHORT TERM...KJS LONG TERM...LTB AVIATION...LTB
Hazardous Weather Outlook National Weather Service Grand Junction CO 426 AM MDT Wed Aug 3 2022 COZ001>014-017>023-UTZ022>025-027>029-041030- 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- 426 AM MDT Wed Aug 3 2022 This hazardous weather outlook is for eastern Utah and western Colorado. .DAY ONE...Today and Tonight Thunderstorm development is possible again today though a noticeable downturn in coverage is expected. The southern Colorado mountains will continue to see the most activity with continued threats of moderate the heavy rainfall rates. All storms will be capable of gusty outflow winds and lightning. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday Monsoon moisture returns in earnest late this week into the weekend with an increasing threat of widespread showers and storms producing heavy rainfall. Thunderstorm development is expected each day. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed.
Special Weather Statement
National Weather Service Grand Junction CO
102 PM MDT Wed Aug 3 2022
COZ009-011-012-031930-
Grand and Battlement Mesas CO-
Central Gunnison and Uncompahgre River Basin CO-
West Elk and Sawatch Mountains CO-
102 PM MDT Wed Aug 3 2022
...A strong thunderstorm will impact portions of east central Delta
and west central Gunnison Counties through 130 PM MDT...
At 101 PM MDT, Doppler radar was tracking a strong thunderstorm 7
miles northeast of Paonia, or 38 miles northeast of Montrose, moving
southeast at 15 mph.
HAZARD...Winds in excess of 40 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 east central Delta
and west central Gunnison Counties, including the following
locations... Bowie and Somerset.
This includes Colorado 133 between mile markers 10 and 23, and
between mile markers 27 and 30.
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 3895 10763 3901 10758 3906 10757 3900 10730
3880 10751
TIME...MOT...LOC 1901Z 309DEG 13KT 3896 10753
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH
ERWSpecial Weather Statement
National Weather Service Grand Junction CO
235 PM MDT Wed Aug 3 2022
COZ017-032100-
Uncompahgre Plateau/Dallas Divide CO-
235 PM MDT Wed Aug 3 2022
...A strong thunderstorm will impact portions of northwestern Ouray
and south central Montrose Counties through 300 PM MDT...
At 235 PM MDT, Doppler radar was tracking a strong thunderstorm 16
miles northeast of Nucla, or 23 miles west of Montrose, moving
southeast at 15 mph.
HAZARD...Winds in excess of 40 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 northwestern Ouray
and south central Montrose Counties.
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.
&&
LAT...LON 3833 10841 3842 10837 3848 10829 3838 10798
3815 10816
TIME...MOT...LOC 2035Z 302DEG 11KT 3837 10828
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH
ERWSpecial Weather Statement
National Weather Service Grand Junction CO
408 PM MDT Wed Aug 3 2022
COZ018-019-032245-
Southwest San Juan Mountains CO-Northwestern San Juan Mountains CO-
408 PM MDT Wed Aug 3 2022
...A strong thunderstorm will impact portions of east central
Hinsdale County through 445 PM MDT...
At 408 PM MDT, Doppler radar was tracking a strong thunderstorm 12
miles west of Creede, or 50 miles south of Gunnison, moving south at
10 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 storm will remain over mainly rural areas of east central
Hinsdale County.
This includes Colorado 149 between mile markers 43 and 55.
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 3795 10701 3795 10705 3796 10707 3795 10709
3795 10710 3794 10711 3794 10714 3771 10714
3771 10727 3783 10731 3806 10701
TIME...MOT...LOC 2208Z 338DEG 7KT 3784 10715
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...30 MPH
KJSThe Grand Junction radar (KGJX), 170 km away, was scanning. The volume nearest the first event began at 23:01 UTC.
1 flash flood. Local standard time, as filed.
Water ran across Forest Service Road 520 near Colorado Highway 149 near the Hinsdale and Mineral County Line due to heavy rain from thunderstorms. Five feet of standing water on the road resulted from a blocked culvert, causing a vehicle to be trapped.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2022Every state in 2022This day in weather historyWarnings in Colorado, August 2022
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: 1035773.