7:55 p.m.: A storm passing over Arapahoe County briefly became a rotating thunderstorm with characteristics of a supercell, according to the National Weather Service.
The storm intensified for about an hour as it moved southeast.
An intensifying thunderstorm in Arapahoe County, CO briefly exhibits supercellular organization and deviant motion ~5:29-6:21 pm MDT on Thursday September 14, 2023. 3D volume rendering via KGLD. Simulated view from the south (looking toward the north). #COwx #KSwx #NEwx pic.twitter.com/vZGmguCGEF
— NWS Goodland (@NWSGoodland) September 15, 2023
6:55 p.m.: Flights leaving Denver International Airport are delayed an average of 1 hour and 45 minutes after a ground stop briefly halted all departures due to thunderstorms, according to the Federal Aviation Administration.
There were 668 flight delays and six cancelations reported today at DIA as of 6:50 p.m., according to FlightAware. There were 244 Southwest flights, 209 United flights and 105 SkyWest flights delayed.
5:20 p.m.: Flooding in the area of Buckhorn Canyon in Larimer County has resolved, according to the Larimer County Sheriff’s Office. It is safe to travel in the area of County Roads 44H and 27.
This is the Larimer County Sheriff’s Office with a situation update. The flooding in the Buckhorn Canyon area of (CR44H & CR27) has solved. You are now okay to travel in this area. https://t.co/6DR7wR442u
— Larimer Sheriff (@LarimerSheriff) September 14, 2023
5:15 p.m.: Colo. 125 in Grand County is closed in both directions between U.S. 40 and Forest Service Road 124 due to a mudslide, according to the Colorado Department of Transportation.
Photos of the mudslide on #CO125 near Mile Post 13. @ColoradoDOT has closed Highway 125 in both directions. #cotrip #grandcounty pic.twitter.com/mVfB3WykXl
— Grand County Sheriff (@GrandCoSheriff) September 14, 2023
5:10 p.m.: Up to 2 inches of rain is expected to fall across the Front Range through Thursday evening, according to the National Weather Service.
Widespread storms that started Thursday morning may cause minor flooding across Denver, the Interstate 25 corridor and plains.
A flash flood warning is in effect in east central Larimer County until 6:15 p.m. as up to 1 inch of rain falls over the Cameron Peak burn scar, according to the National Weather Service.
Debris from the burn scar may flow through the Buckhorn Creek drainage, including rock, mud and vegetation.
5:06 p.m.: County Road 44H in Larimer County has reopened, according to the Larimer County Sheriff’s Office.
County Road 44H has reopened. Please continue to exercise caution as rain moves through the area. #cowx https://t.co/iYWxATohFA
— Larimer Sheriff (@LarimerSheriff) September 14, 2023
4:30 p.m.: The National Weather Service issued a flood advisory for northeastern Denver area, including Thornton, Commerce City, eastern Northglenn, Brighton, northwestern Denver International Airport, Barr Lake, Todd Creek and Henderson.
Impacts could include minor flooding in low-lying areas and areas with poor drainage. The advisory is in effect until 7:30 p.m. Thornton, Brighton and the airport could also see strong winds and half-inch hail until 5:15 p.m.
A special weather statement has been issued for Thornton CO, Denver Intl Airport CO and Brighton CO until 5:15 PM MDT #COwx pic.twitter.com/A25ZM51gVT
— NWS Boulder (@NWSBoulder) September 14, 2023
4:19 p.m.: Colo. 125 in Grand County is closed in both directions because of a mudslide, according to the Grand County Sheriff’s Office. There is no estimated time of reopening.
Happening Now: We are receiving reports of a mudslide on Hwy 125 near Mile Post 13. @ColoradoDOT has closed Hwy 125 in both directions. At this time there is no est. time of reopening.
For the latest road report call 511 or visit https://t.co/mXEnWDxY6Z
#CO125 #grandcounty— Grand County Sheriff (@GrandCoSheriff) September 14, 2023
4:15 p.m.: There is dangerous flooding in the area of Buckhorn Canyon near County Roads 44H and 27 in Larimer County, the Larimer County Sheriff’s Office announced at 4:15 p.m. People should seek higher ground by any means necessary and avoid areas such as low spots, ditches or dips.
No one should attempt to cross flowing streams or creeks, and drivers should be aware that roads covered in flood water may not be intact and should not be driven on. If a vehicle stalls, leave and seek higher ground.
09-14-2023 16:15:38
This is the Larimer County Sheriff’s Office with an emergency message. Dangerous flooding is occurring in the area of Buckhorn Canyon – CR44H & CR27. Immediately reach higher ground by any means necessary. Avoid area subject t https://t.co/NOreeae5CI— Larimer Sheriff (@LarimerSheriff) September 14, 2023
4:09 p.m.: County Road 44H in Larimer County is closed at County Road 27 due to water and debris on the road, with rain expected to continue until at least 6:15 p.m., according to the Larimer County Sheriff’s Office.
County Rd 44H is closed at CR27 due to water and debris on the road. Rain is expected to continue through at least 6:15pm in this area. Please avoid rivers/drainages, seek higher ground, and never try to drive through through flooded or washed out areas. #cowx pic.twitter.com/zrn3kBxd2o
— Larimer Sheriff (@LarimerSheriff) September 14, 2023