An area of low pressure tracked to the north of the region during the day on the 16th, with an associated front draped across northeast Utah and northwest Colorado. An upper level jet streak was tracking across region during this period as well, providing some extra lift.
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 area of low pressure tracked to the north of the region during the day on the 16th, with an associated front draped across northeast Utah and northwest Colorado. An upper level jet streak was tracking across region during this period as well, providing some extra lift. Instability in the realm of 600-800 J/kg of CAPE was also present across this region, as well as ample moisture. All these combined to fire off strong to severe thunderstorms across northeast Utah and northwest Colorado during the afternoon hours. A few storms in northeast Utah produced some hail.
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 Sep 16, 10:50 AM MST, 2 hours 25 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Grand Junction CO 1150 AM MDT Tue Sep 16 2025 .KEY MESSAGES... - Showers and storms will be common across the higher terrain today. In the evening, the northern valleys and mountains and central mountains will be favored. - Temperatures will hover near normal before a warmup kicks in towards the end of the week. - Moisture returns this weekend but confidence in the extent and timing remains low at this time. && .SHORT TERM /THROUGH WEDNESDAY/... Issued at 255 AM MDT Tue Sep 16 2025 Convection has been ongoing all night across northeast Utah and the northern valleys of Colorado thanks to the closed low to our north and impulses moving through the mean flow. Further upstream, showery activity can be seen across Salt Lake City heading up into SW WY. Wouldn't be surprised if these showers make it into our region over the next few hours. Later today, the closed low will slowly drop to the southeast as a cold front begins to move across the area. Decent upper level support in the form of a jet streak moving overhead will bring wide scale ascent to the region. As this occurs, CAPE will reach between 600 to 800 J/kg with a few higher pockets noted later this afternoon. Moisture is also expected to increase so the CAMs forecast for more widespread showers and thunderstorms this afternoon looks spot on. Convection will start over the higher terrain for all but SE Utah and by the evening hours, the northern valleys will become favored as well as the central and northern mountains. Gusty winds, hail, some heavy rain will all be possible from the this convection. On Wednesday, the closed low will have filled leaving an upper level trough to move through. Some isolated convection will be possible, more along the Continental Divide with coverage much less than seen today. Highs on Wednesday will be noticeably cooler especially for the northern valleys and somewhat cooler for the central valleys down to the San Juans. The southern valleys won't see much change as the cool air won't make it that far south. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... Issued at 255 AM MDT Tue Sep 16 2025 By Wednesday night the passing trough will be well east of the Rockies, and drier air will move into the CWA behind it. Moisture lingers a bit in the northern half of our region, but by Thursday afternoon PWATs look to be anomalously low across the area (70-100% of normal). This will limit PoPs Thursday afternoon, and only minimal convection, mostly over the high terrain, is expected. On Thursday while we are between the trough axis to our east, and the ridge axis to our west, we will be under northerly flow that will keep us dry and drop high temperatures by a few degrees to near to 10 degrees below normal. By Friday the ridge will move over our CWA, which will shift flow to southwesterly. Moisture may get pulled into the region with the southwesterly flow, which could raise PoPs a bit along the southern border of our CWA. However, it is around this point that the models start to really diverge, making the forecast unclear. Both the ECMWF Ens and the GFS Ens agree on the timing of the moisture push, but the later seems to favor a forecast for more moisture. With this uncertainty it is difficult to say what the precipitation forecast looks like later this week, but it is clear that moisture does return after the brief period of dry conditions on Thursday. High temperatures climb by a few degrees beginning Friday with the return to ridging aloft. && .AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/... Issued at 1138 AM MDT Tue Sep 16 2025 Isolated showers and thunderstorms currently across the northern and central mountains will spread into the valleys and southern mountains, and will become more scattered over the next couple hours. These storms will continue through the afternoon, diminishing southwest to northeast after 00Z and ending by about 07Z. Brief MVFR will be possible with any stronger cells moving over TAF sites. Otherwise, VFR will remain the predominant flight category. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && SHORT TERM...TGR LONG TERM...GF AVIATION...DB
Hazardous Weather Outlook National Weather Service Grand Junction CO 409 AM MDT Tue Sep 16 2025 COZ001>014-017>023-UTZ022>025-027>029-171015- 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- 409 AM MDT Tue Sep 16 2025 This Hazardous Weather Outlook is for northwest Colorado, southwest Colorado, west central Colorado, east central Utah, northeast Utah and southeast Utah. .DAY ONE...Today and tonight. Widespread showers and thunderstorms will fire today over the higher terrain before favoring the northern valleys and then the northern and central mountains. Gusty winds, hail, and some brief heavy rain will be possible. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. A few isolated showers and storms will be possible along the Divide though coverage will be much less than seen today. Dry weather returns after that with some precip possible over the weekend. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
Preliminary Local Storm Report
National Weather Service Grand Junction CO
1006 AM MDT Tue Sep 16 2025
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0100 PM Flash Flood 6 WSW Meeker 40.02N 107.99W
08/24/2025 Rio Blanco CO Public
Burn scar - flash flooding across County
Road 33, Josephine Basin.
&&Preliminary Local Storm Report
National Weather Service Grand Junction CO
1012 AM MDT Tue Sep 16 2025
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0230 PM Flash Flood 6 WSW Meeker 40.02N 107.99W
08/26/2025 Rio Blanco CO Public
Flash flooding, debris and inundated fields
were observed across County Road 33,
Josephine Basin.
&&Preliminary Local Storm Report
National Weather Service Grand Junction CO
1114 AM MDT Tue Sep 16 2025
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0300 PM Debris Flow 21 WSW Meeker 39.96N 108.27W
08/28/2025 Rio Blanco CO Public
Debris flow and flooding below Lee burn
scar, Bear Gulch over Square S Meadows.
&&Preliminary Local Storm Report
National Weather Service Grand Junction CO
1139 AM MDT Tue Sep 16 2025
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0330 PM Debris Flow 19 WSW Meeker 40.00N 108.25W
08/27/2025 Rio Blanco CO Public
Debris flow along County Road 76 and
inundated fields with mud and debris down to
County Road 5 from the Lee burn scar.
&&Special Weather Statement
National Weather Service Grand Junction CO
151 PM MDT Tue Sep 16 2025
UTZ023-024-162015-
Eastern Uinta Basin UT-Eastern Uinta Mountains UT-
151 PM MDT Tue Sep 16 2025
...A STRONG THUNDERSTORM WILL IMPACT NORTHWESTERN UINTAH COUNTY
THROUGH 215 PM MDT...
At 151 PM MDT, Doppler radar was tracking a strong thunderstorm near
Whiterocks, moving east at 25 mph.
HAZARD...Wind gusts up to 40 mph and half inch hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to vegetation is
possible.
Locations impacted include...
Roosevelt, Whiterocks, and Fort Duchesne.
This includes U.S. Highway 40 in Utah between mile markers 123 and
130.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 4057 10972 4027 10969 4033 10998 4052 10998
TIME...MOT...LOC 1951Z 266DEG 22KT 4042 10997
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH
15The Grand Junction radar (KGJX), 201 km away, was scanning. The volume nearest the first event began at 20:16 UTC.
1 hail. Local standard time, as filed.
At 1322 MST on September 16, a trained spotter reported 1 inch diameter hail 9 miles ESE of Whiterocks, Utah.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2025Every state in 2025This day in weather historyWarnings in Utah, September 2025
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: 1295653.