Flash Flood Prediction Program

Time: 722 PM Sat June 5, 2021 Forecaster: Brad Simmons ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1'S ISSUED FOR DOUGLAS COUNTY ADDITIONAL MESSAGES POSSIBLE THIS EVENING. - Message 1's have been issued for Douglas County and will be valid until 10pm this evening. - Moderate to strong thunderstorms have developed over Douglas County behind a gust front that originated south of the District. As this gust front moves northward additional thunderstorms may develop and additional Message 1's may need to be issued. - Strong thunderstorms will be capable of producing heavy rainfall, hail and gusty winds. Storm motions are very slow or nearly stationary and can lead to a prolonged period of heavy rain that may lead to excessive runoff. STORM RAINFALL POTENTIAL AND DURATION: Moderate to strong thunderstorms will produce 0.3-0.8" in 10-30 minutes. WORST CASE SCENARIO: A nearly stationary strong thunderstorm may result in heavy rainfall of 0.40-1.40" in 15-45 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Douglas County 1 Current TO 1000 PM Current TO 900 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 1000 PM SAT 0.1" (40%) to 0.3" (15%) to 0.8" (5%) LOW Arapahoe Current TO 1000 PM SAT 0.1" (75%) to 0.3" (50%) to 0.8" (15%) MOD Boulder Current TO 1000 PM SAT 0.1" (40%) to 0.3" (15%) to 0.8" (5%) LOW Broomfield Current TO 1000 PM SAT 0.1" (40%) to 0.3" (15%) to 0.8" (5%) LOW Denver Current TO 1000 PM SAT 0.1" (60%) to 0.3" (30%) to 0.8" (10%) LOW Douglas Current TO 1000 PM SAT 0.1" (95%) to 0.3" (75%) to 0.8" (30%) ISSUED Jefferson Current TO 1000 PM SAT 0.1" (75%) to 0.3" (50%) to 0.8" (15%) LOW Foothills above 6500ft       Boulder Current TO 1000 PM SAT 0.1" (40%) to 0.3" (15%) to 0.8" (5%) LOW Douglas Current TO 1000 PM SAT 0.1" (100%) to 0.3" (80%) to 0.8" (40%) ISSUED Jefferson Current TO 1000 PM SAT 0.1" (80%) to 0.3" (60%) to 0.8" (20%) MOD MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS. MHFD Flood Prediction Center: 303-458-0789    F2P2 Website [http://udfcd.org/Flash+Flood+Prediction+Program]