Time: 938 AM Wed July 20, 2022 Forecaster: Laura Smith

Heavy Precipitation Outlook
Flash Flood Prediction Program

SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS
-Flow aloft will be westerly this morning, becoming northwesterly by the afternoon. Hot temperatures in the mid to upper 90's are expected again today, with dew points in the 40's to around 50 degrees. Forecast soundings indicate CAPE values will be around 500 J/kg today leading to scattered, moderate to briefly strong thunderstorms similar to yesterday.
-Storms will begin developing over the foothills around noon and are expected to move east-southeast across the District at 15-20mph. Prime time for storms today is from 1pm to 8pm. Typical thunderstorm activity will produce minimal precipitation between a trace to 0.2" of rainfall, with a low chance for moderate to heavy rainfall of 0.2"-0.6" in 10-30 minutes from moderate to strong thunderstorms.
-Skies will gradually clear this evening with mild and dry conditions expected through the overnight and into Thursday. Overnight lows will dip into the low to mid 60's on the plains with low to mid 50's along the foothills.
STORM RAINFALL POTENTIAL AND DURATION: Rain showers and weak thunderstorms will produce a trace to 0.2" of moisture. Moderate thunderstorms will have the potential to produce rainfall rates of 0.2-0.6" in 10-30 minutes.

WORST CASE SCENARIO: Thunderstorms anchoring to the foothills or surface boundary will have the potential to produce moderate to briefly heavy rainfall of 0.4-0.8" in 10-30 minutes and up to 1.2" in 45-60 minutes.

A LOOK AHEAD: Hot conditions with afternoon showers and thunderstorms will continue this week as a heat dome remains parked over the four-corners region. Similar conditions are expected Thursday and Friday as high temperatures remain in the mid to upper 90's, possibly reaching 100 degrees in some areas, with afternoon showers and thunderstorms. This pattern is expected to continue through the weekend.

Location Prime Time 30-Minute Rainfall
and % Probability
Message
Potential
Plains      
Adams 100 PM TO 800 PM
Trace (60%) to 0.2" (30%) to 0.6" (15%) LOW
Arapahoe 100 PM TO 800 PM
Trace (60%) to 0.2" (30%) to 0.6" (15%) LOW
Boulder 100 PM TO 800 PM
Trace (60%) to 0.2" (30%) to 0.6" (15%) LOW
Broomfield 100 PM TO 800 PM
Trace (60%) to 0.2" (30%) to 0.6" (15%) LOW
Denver 100 PM TO 800 PM
Trace (60%) to 0.2" (30%) to 0.6" (15%) LOW
Douglas 100 PM TO 800 PM
Trace (60%) to 0.2" (30%) to 0.6" (15%) LOW
Jefferson 100 PM TO 800 PM
Trace (60%) to 0.2" (30%) to 0.6" (15%) LOW
Foothills above 6500ft      
Boulder 1200 PM TO 800 PM
Trace (80%) to 0.2" (30%) to 0.6" (15%) LOW
Douglas 1200 PM TO 800 PM
Trace (80%) to 0.2" (40%) to 0.6" (20%) LOW
Jefferson 1200 PM TO 800 PM
Trace (80%) to 0.2" (40%) to 0.6" (20%) LOW
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.
https://f2p2.udfcd.org/generator/