Time: 433 PM Tue July 25, 2023 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 9:30 PM this evening. Thunderstorms have begun to develop over the District with typical storms generally producing light to moderate rain and gusty winds. Stronger storms that form along outflow boundaries may move more slowly. Strong thunderstorms may also contain hail. Most storms will move from W to E at around 20-25mph with an anchored or slower moving strong thunderstorm having the potential to produce extended periods of heavy rainfall that may lead to excessive runoff roadways. 1-2 rounds of thunderstorms are expected with best chances for thunderstorms through 8:30 PM. After 8:30 or 9:00 PM thunderstorms are expected to diminish or have moved east of the District. STORM RAINFALL POTENTIAL AND DURATION: Typical thunderstorms will produce moderate rainfall of up to 0.25” in 10-30 minutes. Strong thunderstorms have the potential to produce heavy rainfall up to 0.50” in 10-30 minutes. WORST CASE SCENARIO: Anchored or training thunderstorms have the potential to produce 0.50” to 1.00” in 60 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Jefferson County 1 Current TO 930 PM Current TO 830 PM Boulder County 1 Current TO 930 PM Current TO 830 PM Broomfield County 1 Current TO 930 PM Current TO 830 PM Douglas County 1 Current TO 930 PM Current TO 830 PM Adams County 1 Current TO 930 PM Current TO 830 PM Denver County 1 Current TO 930 PM Current TO 830 PM DIA 1 Current TO 930 PM Current TO 830 PM Arapahoe County 1 Current TO 930 PM Current TO 830 PM the City of Aurora 1 Current TO 930 PM Current TO 830 PM Arvada 1 Current TO 930 PM Current TO 830 PM Wheat Ridge 1 Current TO 930 PM Current TO 830 PM Lakewood 1 Current TO 930 PM Current TO 830 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 930 PM TUE 0.1" (80%) to 0.3" (50%) to 0.8" (20%) ISSUED Arapahoe Current TO 930 PM TUE 0.1" (80%) to 0.3" (50%) to 0.8" (20%) ISSUED Boulder Current TO 930 PM TUE 0.1" (75%) to 0.3" (40%) to 0.8" (15%) ISSUED Broomfield Current TO 930 PM TUE 0.1" (75%) to 0.3" (40%) to 0.8" (15%) ISSUED Denver Current TO 930 PM TUE 0.1" (80%) to 0.3" (50%) to 0.8" (20%) ISSUED Douglas Current TO 930 PM TUE 0.1" (80%) to 0.3" (50%) to 0.8" (20%) ISSUED Jefferson Current TO 930 PM TUE 0.1" (80%) to 0.3" (50%) to 0.8" (20%) ISSUED Foothills above 6500ft       Boulder Current TO 930 PM TUE 0.1" (80%) to 0.3" (50%) to 0.8" (20%) ISSUED Douglas Current TO 930 PM TUE 0.1" (80%) to 0.3" (50%) to 0.8" (20%) ISSUED Jefferson Current TO 930 PM TUE 0.1" (80%) to 0.3" (50%) to 0.8" (20%) 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]