Flash Flood Prediction Program

Time: 245 PM Wed August 7, 2024 Forecaster: Laura Smith ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- Messages have been issued for the entire District Storms have started to initiate along the foothills and are expected to start moving into the District over the next hour. Like yesterday, slow moving, gust-front driven storms are expected to propagate from west to east around 15-20 mph. However, gust fronts will likely result in additional, slower-moving thunderstorms which will have the potential for moderate to heavy rainfall. Heavy Rainfall is most likely to occur until 9:30 PM tonight. A few lingering showers may persist later through the evening and overnight ahead of the cold front. At this time, the approaching cold front is expected to move through the District early tomorrow morning. There is still some uncertainty about the timing of the front, which will depend on how long the cool airmass stalls north of the Cheyenne Ridge. We will continue to monitor this system as it tracks south and update as needed. STORM RAINFALL POTENTIAL AND DURATION: Thunderstorms will have the potential to produce rainfall rates of 0.30”-0.90” in 10-30 minutes. WORST CASE SCENARIO: A slow-moving thunderstorm or a large thunderstorm complex may result in up to 1.80” of rain in 45-60 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Boulder County 1 Current TO 1000 PM Current TO 930 PM Jefferson County 1 Current TO 1000 PM Current TO 930 PM Broomfield County 1 Current TO 1000 PM Current TO 930 PM Douglas County 1 Current TO 1000 PM Current TO 930 PM Adams County 1 Current TO 1000 PM Current TO 930 PM Denver County 1 Current TO 1000 PM Current TO 930 PM DIA 1 Current TO 1000 PM Current TO 930 PM Arapahoe County 1 Current TO 1000 PM Current TO 930 PM the City of Aurora 1 Current TO 1000 PM Current TO 930 PM Arvada 1 Current TO 1000 PM Current TO 930 PM Wheat Ridge 1 Current TO 1000 PM Current TO 930 PM Lakewood 1 Current TO 1000 PM Current TO 930 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 1000 PM WED 0.3" (55%) to 0.55" (35%) to 0.9" (15%) ISSUED Arapahoe Current TO 1000 PM WED 0.3" (55%) to 0.55" (35%) to 0.9" (15%) ISSUED Boulder Current TO 1000 PM WED 0.3" (55%) to 0.55" (35%) to 0.9" (15%) ISSUED Broomfield Current TO 1000 PM WED 0.3" (55%) to 0.55" (35%) to 0.9" (15%) ISSUED Denver Current TO 1000 PM WED 0.3" (55%) to 0.55" (35%) to 0.9" (15%) ISSUED Douglas Current TO 1000 PM WED 0.3" (55%) to 0.55" (35%) to 0.9" (15%) ISSUED Jefferson Current TO 1000 PM WED 0.3" (55%) to 0.55" (35%) to 0.9" (15%) ISSUED Foothills above 6500ft       Boulder Current TO 1000 PM WED 0.3" (55%) to 0.55" (35%) to 0.9" (15%) ISSUED Douglas Current TO 1000 PM WED 0.3" (55%) to 0.55" (35%) to 0.9" (15%) ISSUED Jefferson Current TO 1000 PM WED 0.3" (55%) to 0.55" (35%) to 0.9" (15%) 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]