Time: 714 PM Thu June 24, 2021 Forecaster: Brad Simmons ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1'S CONTINUE VALID FOR THE DISTRICT - Message 1's will continue valid until 9:00pm although the threat for heavy rainfall is rapidly diminishing now that temperatures have cooled into the upper 60's to lower 70's. - The strongest storms of the day traversed from roughly Broomfield through Adams County between 5:30-7:00pm and generally produced 0.1-0.6" of rainfall in 10-30 minutes. A quiet period is expected over the next hour with another weaker wave of showers/thunderstorms W of the Continental Divide that is poised to produce additional shower activity this evening over the District. - With the cooler temperatures the incoming wave later this evening is expected to remain weak and produce a few scattered showers but an isolated thunderstorm cannot be ruled out and could produce brief moderate/heavy rain. A modest chance for shower activity will continue after Messages expire until midnight. STORM RAINFALL POTENTIAL AND DURATION: Rain showers and weak thunderstorms will produce a trace to 0.2" of rain. Moderate to strong thunderstorms will produce 0.2-0.6" of rain in 10-30 minutes. WORST CASE SCENARIO: Training of thunderstorm cells may result in up to 1.2" of rainfall in 30-60 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Lakewood 1 Current TO 900 PM Current TO 730 PM Wheat Ridge 1 Current TO 900 PM Current TO 730 PM Arvada 1 Current TO 900 PM Current TO 730 PM the City of Aurora 1 Current TO 900 PM Current TO 730 PM Arapahoe County 1 Current TO 900 PM Current TO 730 PM DIA 1 Current TO 900 PM Current TO 730 PM Denver County 1 Current TO 900 PM Current TO 730 PM Adams County 1 Current TO 900 PM Current TO 730 PM Douglas County 1 Current TO 900 PM Current TO 730 PM Broomfield County 1 Current TO 900 PM Current TO 730 PM Jefferson County 1 Current TO 900 PM Current TO 730 PM Boulder County 1 Current TO 900 PM Current TO 730 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 900 PM THU Trace (80%) to 0.2" (40%) to 0.6" (10%) ISSUED Arapahoe Current TO 900 PM THU Trace (80%) to 0.2" (40%) to 0.6" (10%) ISSUED Boulder Current TO 900 PM THU Trace (80%) to 0.2" (40%) to 0.6" (10%) ISSUED Broomfield Current TO 900 PM THU Trace (80%) to 0.2" (40%) to 0.6" (10%) ISSUED Denver Current TO 900 PM THU Trace (80%) to 0.2" (40%) to 0.6" (10%) ISSUED Douglas Current TO 900 PM THU Trace (80%) to 0.2" (40%) to 0.6" (10%) ISSUED Jefferson Current TO 900 PM THU Trace (80%) to 0.2" (40%) to 0.6" (10%) ISSUED Foothills above 6500ft       Boulder Current TO 900 PM THU Trace (80%) to 0.2" (40%) to 0.6" (10%) ISSUED Douglas Current TO 900 PM THU Trace (80%) to 0.2" (40%) to 0.6" (10%) ISSUED Jefferson Current TO 900 PM THU Trace (80%) to 0.2" (40%) to 0.6" (10%) ISSUED MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS. MHFD Flood Prediction Center: 303-458-0789    F2P2 Website [http://udfcd.org/Flash+Flood+Prediction+Program]