Time: 951 AM Sat July 31, 2021 Forecaster: Justin Brooks ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 2'S CONTINUE VALID UNTIL 9:00 PM THIS EVENING - Message 2's continue valid until 9pm as the threat for heavy rainfall continues into this afternoon and evening. - Cooler and cloudy this morning with a few lingering rain showers out on the eastern plains at this time. High temperatures today will reach the mid to upper 70's this afternoon which could help limit the potential for stronger storms. However, with adequate moisture still in place, even moderate storms could produce heavy rainfall with the chance for longer duration rainfall from storms that form along outflow boundaries that remain stationary for an extended period of time. Storm chances will start between noon and 1pm, with prime time between 4-9pm. With the recent moisture it may not take as much rain to produce excessive runoff and possibly flash flooding. - A chance will remain for a few scattered lingering rain showers through the evening and into the overnight. Overnight skies will remain cloudy with lows dropping into the 60's on the plains with mid to upper 50's along the foothills. STORM RAINFALL POTENTIAL AND DURATION: Weak thunderstorms will produce 0.2-0.6" in 10-30 minutes. Moderate to strong thunderstorms will have the potential to produce 0.6-1.8" of heavy rain in 10-30 minutes. WORST CASE SCENARIO: A strong thunderstorm will have the potential to produce up to 3.6" in 45-60 minutes. Storms that persist beyond 60 minutes may produce locally higher amounts. COUNTY MESSAGE VALID TIMES PRIME TIME the City of Aurora 2 Current TO 900 PM Current TO 900 PM Arapahoe County 2 Current TO 900 PM Current TO 900 PM DIA 2 Current TO 900 PM Current TO 900 PM Denver County 2 Current TO 900 PM Current TO 900 PM Adams County 2 Current TO 900 PM Current TO 900 PM Douglas County 2 Current TO 900 PM Current TO 900 PM Broomfield County 2 Current TO 900 PM Current TO 900 PM Jefferson County 2 Current TO 900 PM Current TO 900 PM Boulder County 2 Current TO 900 PM Current TO 900 PM Lakewood 2 Current TO 900 PM Current TO 900 PM Wheat Ridge 2 Current TO 900 PM Current TO 900 PM Arvada 2 Current TO 900 PM Current TO 900 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 900 PM SAT 0.2" (80%) to 0.6" (60%) to 1.8" (30%) ISSUED Arapahoe Current TO 900 PM SAT 0.2" (80%) to 0.6" (60%) to 1.8" (30%) ISSUED Boulder Current TO 900 PM SAT 0.2" (80%) to 0.6" (60%) to 1.8" (30%) ISSUED Broomfield Current TO 900 PM SAT 0.2" (80%) to 0.6" (60%) to 1.8" (30%) ISSUED Denver Current TO 900 PM SAT 0.2" (80%) to 0.6" (60%) to 1.8" (30%) ISSUED Douglas Current TO 900 PM SAT 0.2" (80%) to 0.6" (60%) to 1.8" (30%) ISSUED Jefferson Current TO 900 PM SAT 0.2" (80%) to 0.6" (60%) to 1.8" (30%) ISSUED Foothills above 6500ft       Boulder Current TO 900 PM SAT 0.2" (90%) to 0.6" (70%) to 1.8" (40%) ISSUED Douglas Current TO 900 PM SAT 0.2" (90%) to 0.6" (70%) to 1.8" (40%) ISSUED Jefferson Current TO 900 PM SAT 0.2" (90%) to 0.6" (70%) to 1.8" (40%) 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]