Time: 837 AM Sat July 24, 2021 Forecaster: Justin Brooks

Heavy Precipitation Outlook
Flash Flood Prediction Program

COOL TODAY WITH A SLIGHT CHANCE FOR RAIN SHOWERS/ISOLATED THUNDERSTORMS THIS AFTERNOON AND EARLY EVENING
-A cold front will result in cooler high temperatures today with upper 70's to low 80's across the plains with low to mid 70's along the foothills. Currently a few scattered weak to moderate showers along the Palmer Divide and into southern portions of the District. These showers will remain in place through most of the morning and into the afternoon which should also help limit temperatures with increased cloud cover throughout the day.
-However, with adequate surface moisture and possibly a few breaks in the clouds, could raise temperatures enough to get a stronger storm to develop along the Palmer Divide which in turn could produce a gust front which would have the potential to trigger storms northward and into the District. The best chance for storms to develop today will be between noon and 6pm with a few scattered rain showers possible through sunset and into the early evening before skies gradually clear out after midnight.
-Overnight will be mild with lows dropping into the mid to upper 60's for the plains with upper 50's to low 60's along the foothills.
STORM RAINFALL POTENTIAL AND DURATION: Weak to moderate thunderstorms will produce TR-0.2" in 10-30 minutes. Strong thunderstorms have the potential to produce 0.2-0.8" of heavy rain in 10-30 minutes.

WORST CASE SCENARIO: A nearly stationary strong thunderstorm may result in up to 1.6" in 60 minutes or less.

A LOOK AHEAD: Sunday will already begin a decent warm up as high temperatures jump back into the 90's resulting in a slightly better chance for afternoon rain showers/isolated thunderstorms. With excess moisture in place at the surface and in the mid to upper-level another low chance for heavy rain will persist into Sunday. Heat and high-pressure returns Monday and through the rest of next week keeping high temperatures in the 90's with only a slight chance for afternoon/evening rain showers/isolated thunderstorms.

Location Prime Time 30-Minute Rainfall
and % Probability
Message
Potential
Plains      
Adams 1200 PM TO 900 PM
Trace (40%) to 0.2" (20%) to 0.8" (5%) LOW
Arapahoe 1200 PM TO 900 PM
Trace (40%) to 0.2" (20%) to 0.8" (5%) LOW
Boulder 1200 PM TO 900 PM
Trace (40%) to 0.2" (20%) to 0.8" (5%) LOW
Broomfield 1200 PM TO 900 PM
Trace (40%) to 0.2" (20%) to 0.8" (5%) LOW
Denver 1200 PM TO 900 PM
Trace (40%) to 0.2" (20%) to 0.8" (5%) LOW
Douglas 1200 PM TO 900 PM
Trace (60%) to 0.2" (30%) to 0.8" (15%) MOD
Jefferson 1200 PM TO 900 PM
Trace (50%) to 0.2" (25%) to 0.8" (10%) LOW
Foothills above 6500ft      
Boulder 1200 PM TO 900 PM
Trace (40%) to 0.2" (20%) to 0.8" (5%) LOW
Douglas 1200 PM TO 900 PM
Trace (60%) to 0.2" (30%) to 0.8" (15%) MOD
Jefferson 1200 PM TO 900 PM
Trace (50%) to 0.2" (25%) to 0.8" (10%) LOW
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.
https://f2p2.udfcd.org/generator/