Time: 838 PM Wed August 2, 2023 Forecaster: Justin Brooks ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1’S HAVE BEEN EXTENDED UNTIL 11:00 PM Message 1’s have been extended as the threat of heavy rainfall remains over the District. A line of storms is currently moving into the District from the southwest. A gust front from the northeast is also moving into the District and these will converge over the District over the next few hours. Behind this gust front, dew points are very elevated, around 60 degrees, resulting in a good chance for efficient rainfall producing storms. Currently storm motions are fairly brisk out of the southwest between 15-25mph, although storm movements may become erratic once the gust front from the northeast moves in. The strongest storms are currently in Douglas County and are expected to move northeastward and into Denver and Arapahoe Counties. Additional storms could initiate in north and northwestern portions of the District, however the best chance for heavy rainfall will likely be for south and southeastern portions of the District through the rest of the evening. Stronger storms should diminish by 10pm with light to moderate storms through 11pm. STORM RAINFALL POTENTIAL AND DURATION: Typical showers/thunderstorms will produce a 0.05-0.25” total in 10 to 30 minutes. A moderate thunderstorm will produce 0.25” to 0.75” total in 10 to 30 minutes. A strong thunderstorm will produce 0.75” to 1.25” total in 10 to 30 minutes. WORST CASE SCENARIO: An anchored strong thunderstorm or training of thunderstorm cells has the potential to produce up to 2.5” in under 60 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Lakewood 1 Current TO 1100 PM Current TO 1030 PM Wheat Ridge 1 Current TO 1100 PM Current TO 1030 PM Arvada 1 Current TO 1100 PM Current TO 1030 PM the City of Aurora 1 Current TO 1100 PM Current TO 1030 PM Arapahoe County 1 Current TO 1100 PM Current TO 1030 PM DIA 1 Current TO 1100 PM Current TO 1030 PM Denver County 1 Current TO 1100 PM Current TO 1030 PM Adams County 1 Current TO 1100 PM Current TO 1030 PM Douglas County 1 Current TO 1100 PM Current TO 1030 PM Broomfield County 1 Current TO 1100 PM Current TO 1030 PM Jefferson County 1 Current TO 1100 PM Current TO 1030 PM Boulder County 1 Current TO 1100 PM Current TO 1030 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 1100 PM WED 0.25" (75%) to 0.75" (35%) to 1.25" (15%) ISSUED Arapahoe Current TO 1100 PM WED 0.25" (80%) to 0.75" (40%) to 1.25" (20%) ISSUED Boulder Current TO 1100 PM WED 0.25" (60%) to 0.75" (30%) to 1.25" (15%) ISSUED Broomfield Current TO 1100 PM WED 0.25" (60%) to 0.75" (30%) to 1.25" (15%) ISSUED Denver Current TO 1100 PM WED 0.25" (80%) to 0.75" (40%) to 1.25" (20%) ISSUED Douglas Current TO 1100 PM WED 0.25" (80%) to 0.75" (40%) to 1.25" (20%) ISSUED Jefferson Current TO 1100 PM WED 0.25" (60%) to 0.75" (30%) to 1.25" (15%) ISSUED Foothills above 6500ft       Boulder Current TO 1100 PM WED 0.25" (50%) to 0.75" (25%) to 1.25" (10%) ISSUED Douglas Current TO 1100 PM WED 0.25" (50%) to 0.75" (25%) to 1.25" (10%) ISSUED Jefferson Current TO 1100 PM WED 0.25" (50%) to 0.75" (25%) to 1.25" (10%) 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]