Thunderstorms will roll across the Front Range and over the eastern plains Monday afternoon and evening, with the greatest risk of severe weather east of Interstate 25 to Sterling, Akron and Limon, according to the National Weather Service out of Boulder.
Gusty winds and heavy rainfall are possible, but forecasters warned that the main threats are large hail on the plains and an elevated threat of flash flooding at the burn scars for the Alexander Mountain Fire and Cameron Peak Fire.
The risk of flash flooding in these areas is mainly between 1 p.m. and 6 p.m., NWS reported. Anybody traveling around the burn scars Monday should avoid ditches and low-lying areas.
A flood advisory was issued until 7 p.m. for the Stone Canyon Fire burn scar, as "minor debris and ash flows and flooding caused by excessive rainfall is expected," the NWS said.
After 6 p.m., the stronger storms will have spread to the eastern plains.
NWS said the greatest threat for severe weather on the plains Monday afternoon and evening will happen in Lincoln, Washington and Logan counties, as well as parts of Weld County, where there will be a minor threat of flash flooding.
Once there, the systems may drop as much as 2 to 3 inches of rain in an hour, NWS said. Localized flash flooding of small creeks and streams is possible.
A severe thunderstorm watch was issued around 1:45 p.m. Monday for much of the eastern plains, as well as the Fort Collins, Colorado Springs and Pueblo areas. The watch also includes parts of Wyoming and Nebraska. It expires at 9 p.m. Monday.
The following Colorado counties are included in this severe thunderstorm watch:
- Cheyenne
- El Paso
- Lincoln
- Otero
- Weld
- Crowley
- Kiowa
- Logan
- Pueblo
- Yuma
- Elbert
- Kit Carson
- Morgan
- Washington
The NWS issued multiple severe thunderstorm warnings through Monday afternoon, including northeastern Weld County, northwestern Logan County, southeastern Elbert County, southwest Lincoln County, Fremont County, El Paso County and northwestern Pueblo County.
Heavy rainfall is likely with these storms, and both a flood advisory and flash flood warning were issued:
- The flood advisory is in effect for minor flooding in low-lying and spots with poor drainage, and will last until 6:30 p.m. It impacts eastern Adams County, northeastern Arapahoe County, south-central Morgan County and west-central Washington County.
- A flash flood warning was issued from 4 p.m. to 7 p.m. for eastern Adams County, northeastern Arapahoe County and west-central Washington County after a radar detected a thunderstorm that had already dropped 2.5 to 3.5 inches of rain, with an additional inch expected. Another warning was issued for central Elbert County until 7:15 p.m.
Another flash flood warning was issued at 1:36 p.m. for central Elbert County after a radar indicated a thunderstorm producing heavy rain in the area. Between 2 and 3 inches of rain has already fallen, with an additional inch expected, meaning flash flooding is either happening or expected to begin soon, the NWS said. The warning, which expires at 4:30 p.m., covers East Bijou Creek, Reed Springs Creek and Big Sandy Creek.
At 3 p.m., the NWS issued a tornado warning for Elbert County, including Simla and Matheson. It expired about 30 minutes later.
The Denver metro area will mostly avoid these storms, with a lower threat for any heavy rain or severe weather, though the NWS noted that "brief heavy rain and microburst winds (up) to 50 mph will be possible."
Forecasters said a "Denver cyclone" is "a good bet" as well, which happens when the air comes down off the Palmer Divide and curls back toward the Denver area.
Tuesday may bring a few afternoon storms as well, with more expected Wednesday through Friday.
MORE: Hourly forecast | Latest forecast | Radars | Traffic | Weather Page | 24/7 Weather Stream
Stream live, current temperatures plus radars across Colorado anytime for free on the free Denver7+ app on your TV or watch from your computer or mobile phone anytime.