An upper trough moved through the region and interacted with subtropical moisture which resulted in numerous showers and thunderstorms, some with heavy rainfall.
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.
An upper trough moved through the region and interacted with subtropical moisture which resulted in numerous showers and thunderstorms, some with heavy rainfall.
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 7, 2:14 PM MST, 46 minutes earlier.
Area Forecast Discussion National Weather Service Grand Junction CO 314 PM MDT SUN AUG 7 2016 .SHORT TERM...(This evening through Monday night) Issued at 314 PM MDT Sun Aug 7 2016 Moisture has dropped off a little, for less clouds and more sun earlier today. As a result of this better sunshine, and still sufficient moisture, another round of thunderstorms has developed this afternoon. A few of these storms have been fairly energetic, and expect that some have produced small hail and strong wind gusts. The stronger storms seem to be tracking over northeast UT and northwest CO, in better proximity to a disturbance passing over the central/northern Great Basin. The upper flow is also stronger over the north, for faster storm motion and subsequent outflows. Slower moving storms have developed over the southern half, where heavy rain is more of a concern. Soils across much of this portion of the area are already saturated from rain that occurred during the previous few days. Therefore it will not take that much rain to produce runoff problems. Expect this activity to diminishing mid-late this evening as daytime heating drops off. Also, the air mass will continue to slowly dry. In spite of the decreasing clouds the still moderate amount of moisture will keep temperatures mostly above normal overnight. While the drying trend will continue Mon and Mon night, some mainly afternoon/evening showers and thunderstorms will again develop. However coverage and intensity should be less for the most part. High temperatures will warm to around normal values at most locations...with little change in overnight lows. .LONG TERM...(Tuesday through Sunday) Issued at 314 PM MDT Sun Aug 7 2016 Tuesday promises to be the 'dry' day before the next monsoonal surge moves into the region on Wednesday. Even with the drying, some showers and thunderstorms will again develop during the afternoon. But this activity will be noticeable less than we have seen recently, and will be mostly over the higher terrain. On Wednesday a deep moisture surge, along with an embedded disturbance will move up from the south on the monsoonal flow. Therefore we can expect to see an increase in showers and thunderstorms across the area, favoring the south. Runoff may again become problematic, especially if soils in some areas have not had a chance to dry out. The flow will become west then northwest Thu through Thu night as a low pressure disturbance over the Pacific northwest tracks eastward. This drags along its associated western trough. As this brushes the area on Wed night into Thu, expect that showers and thunderstorms will remain plentiful. Once this system passes to the east, high pressure will build along the west coast. This large scale pattern with the high to our west, typically shuts the door to the southerly monsoonal flow and associated moisture. Therefore we can expect drier conditions for the end of the work week and weekend. However the flow will remain on the light side with no mechanism for scouring out all the lingering moisture. So expect some comparatively low- grade terrain based convection each afternoon and evening. After cooler conditions on Wed and Thu, high temps should trend towards normal numbers through the end of the period. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 314 PM MDT Sun Aug 7 2016 While moisture is not at deep as the previous few days, this afternoon's more plentiful sunshine has allowed scattered to numerous convective showers and thunderstorms to develop. This activity will favor the mountains through the late afternoon and evening, and will be capable of producing heavy rainfall, outflow winds to 40 MPH and may obscure higher peaks and ridges at times. Meanwhile, airports across the region face a 20 to 30 percent chance of thunderstorms through the early evening which could result in CIGS below ILS breakpoints along with MVFR visibility in heavy rain. This activity will diminish by around 03Z and end by midnight. Depending upon where rain falls this afternoon and evening, there is a possibility for IFR CIGS due to low stratus and MVFR visibility in light fog late tonight and early Mon morning. && .GJT Watches/Warnings/Advisories... CO...None. UT...None. && SHORT TERM...EH LONG TERM...EH AVIATION...EH
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
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE GRAND JUNCTION CO 258 PM MDT SUN AUG 7 2016 UTZ023-024-072130- EASTERN UINTA BASIN UT-EASTERN UINTA MOUNTAINS UT- 258 PM MDT SUN AUG 7 2016 ...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL UINTAH COUNTY UNTIL 330 PM MDT... AT 256 PM MDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 16 MILES WEST OF DINOSAUR...OR 22 MILES SOUTHEAST OF VERNAL...MOVING NORTHEAST AT 30 MPH. HALF INCH HAIL AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH THIS STORM. THIS STORM WILL REMAIN OVER MAINLY RURAL AREAS OF EAST CENTRAL UINTAH COUNTY AND COULD IMPACT AREAS ALONG HIGHWAY 40 BETWEEN VERNAL AND DINOSAUR. LAT...LON 4011 10937 4016 10944 4044 10908 4018 10906 TIME...MOT...LOC 2056Z 234DEG 26KT 4017 10930 15
The national radar mosaic for the moment the first event began.
2 debris flow, 2 heavy rain. Local standard time, as filed.
Highway 145 between Sawpit and Placerville was closed due to a flow of water, mud, and debris that washed over the road at several points, especially at mile markers 78 and 82.
A member of the public measured 1.03 inches of rain southwest of the Massadona area from the evening of August 7th to the morning of August 8th.
Some driveways and garages in Placerville experienced minor flooding. Additionally, minor flooding was reported on Highway 62 north of Placerville.
A mudslide occurred along Highway 141 between mile markers 107 and 109.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2016Every state in 2016This day in weather historyWarnings in Colorado, August 2016
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: 683103, 683104, 700182, 683117.