Flash Flood Prediction Program

Time: 214 PM Sun July 4, 2021 Forecaster: Brad Simmons ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1'S ISSUED FOR THE ENTIRE DISTRICT - Message 1's have been issued for the entire District and will be valid until 8:30pm this evening. - Thunderstorms are beginning to develop in and around the District currently. Prime time for thunderstorms is from 3-8pm. Upper level steering winds from NW to SE at around 15mph will keep the the storms slowly moving along with stronger thunderstorms capable of producing heavy rainfall that may lead to excessive runoff and possibly flash flooding. - Strong thunderstorms may also become severe with large hail and gusty winds being the primary threats. STORM RAINFALL POTENTIAL AND DURATION: Moderate to strong thunderstorms will have the potential to produce 0.4-1.0" in 10-30 minutes. WORST CASE SCENARIO: A large, slower moving strong thunderstorm may result in up to 1.8" of heavy rainfall in 45-60 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Lakewood 1 Current TO 830 PM 300 PM TO 730 PM Wheat Ridge 1 Current TO 830 PM 300 PM TO 730 PM Arvada 1 Current TO 830 PM 300 PM TO 730 PM the City of Aurora 1 Current TO 830 PM 300 PM TO 730 PM Arapahoe County 1 Current TO 830 PM 300 PM TO 730 PM DIA 1 Current TO 830 PM 300 PM TO 730 PM Denver County 1 Current TO 830 PM 300 PM TO 730 PM Adams County 1 Current TO 830 PM 300 PM TO 730 PM Douglas County 1 Current TO 830 PM 300 PM TO 730 PM Broomfield County 1 Current TO 830 PM 300 PM TO 730 PM Jefferson County 1 Current TO 830 PM 300 PM TO 730 PM Boulder County 1 Current TO 830 PM 300 PM TO 730 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 830 PM SUN 0.1" (90%) to 0.4" (60%) to 0.9" (30%) ISSUED Arapahoe Current TO 830 PM SUN 0.1" (90%) to 0.4" (60%) to 0.9" (30%) ISSUED Boulder Current TO 830 PM SUN 0.1" (90%) to 0.4" (60%) to 0.9" (30%) ISSUED Broomfield Current TO 830 PM SUN 0.1" (90%) to 0.4" (60%) to 0.9" (30%) ISSUED Denver Current TO 830 PM SUN 0.1" (90%) to 0.4" (60%) to 0.9" (30%) ISSUED Douglas Current TO 830 PM SUN 0.1" (90%) to 0.4" (60%) to 0.9" (30%) ISSUED Jefferson Current TO 830 PM SUN 0.1" (90%) to 0.4" (60%) to 0.9" (30%) ISSUED Foothills above 6500ft       Boulder Current TO 830 PM SUN 0.1" (90%) to 0.4" (60%) to 0.9" (30%) ISSUED Douglas Current TO 830 PM SUN 0.1" (90%) to 0.4" (60%) to 0.9" (30%) ISSUED Jefferson Current TO 830 PM SUN 0.1" (90%) to 0.4" (60%) to 0.9" (30%) 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]