The National Weather Service issued a flash flood watch for Southwest Colorado and a severe thunderstorm watch for all of western Colorado with possible high winds and large hail.
The severe thunderstorm watch will end at 5 p.m. today; the flash flood watch at 4 p.m. The weather system could produce wind gusts over 58 mph, 1-inch diameter hail or larger, very heavy rainfall and frequent lightning.
Rainfall could range from 0.25 inches to 1 inch, depending on the location in relation to the storm. The stormy weather is fueled by moisture-rich air in the Southwest pulling northeast toward Wyoming. After 5 p.m., the weather will likely calm down rapidly with cooler temperatures for Sunday and Monday.
“There’s a lot of instability in the atmosphere right now,” said Jeff Colton, a meteorologist with the NWS.
A severe thunderstorm watch means people should be prepared for thunderstorms in and near the watch area, according to the NWS. Severe thunderstorm watches are relatively rare for this part of the country, especially one issued in the morning.
People should stay informed and be ready to act if a warning is issued. A warning means severe weather has been reported by spotters or indicated by radar. Warnings indicate imminent danger to life and property. The NWS advises people to take shelter in a substantial building and get out of mobile homes that can blow over in high winds.
San Miguel, Dolores and other southwestern Colorado counties near Utah had a severe thunderstorm warning as of 11 a.m. Saturday, according to an NWS weather map. La Plata, Montezuma and Archuleta counties were under a severe thunderstorm watch.
The flash flood watch for Southwest Colorado will last until 4 p.m. San Juan County, Utah, had a flash flood warning as of 11 a.m., according to the NWS. The NWS received reports of hail up to 1.5 inches in diameter in southeast Utah, Colton said.
“These storms are producing extremely heavy rain in a short amount of time. That would increase flash flood potential, especially on (the 416 Fire) burn scar,” he said.
Debris in the burn scar area would start moving at a certain rate of rainfall, around 0.25 inches in 15 minutes, he said.
Thunderstorms can also increase fire potential, Colton said. The Southwest region is still in a deep drought, and fires can still be sparked by lightning, even with rainfall. Wind gusts of over 50 or 60 mph could help any fire start to spread.