Flash Flood Prediction Program

Time: 331 PM Sat August 10, 2024 Forecaster: Justin Brooks ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1’S HAVE BEEN ISSUED EFFECTIVE UNTIL 11:00 PM Message 1’s have been issued, effective until 11pm this evening as the potential for showers and thunderstorms with moderate to heavy rainfall increases this afternoon. A few showers and thunderstorms north of the District have produced a gust front which is currently moving into the District from the north with 25-35mph gusts. This gust front will continue through the District over the next couple of hours as storms start to approach from the west. The best chance for storms in the District will likely start over the next hour with a couple of rounds of storms possible this afternoon and evening. Temperatures today reach the mid 80s, resulting in a better chance for thunderstorms activity today. Dew points remain in the low to mid 50s, combined with good upper-level support into the late evening hours will result in a good chance for isolated moderate to heavy rainfall. The largest threat today will be a quick 0.50” in 10-15 minutes, rather than any long-lasting rainfall as storm motions remain between 15-25mph. This quick motion should help limit point rainfall amounts, although gust fronts could result in some erratic storm motions leading to a better chance for brief heavy rainfall. Skies will slowly clear out after midnight tonight with overnight temperatures dropping to around 60 on the plains with mid 50s along the foothills. Once again, a few areas of patchy fog will be possible in the early morning hours. STORM RAINFALL POTENTIAL AND DURATION: Typical showers will produce a 0.05-0.30" total in 10-30 minutes. A moderate to strong thunderstorm will produce rainfall rates of 0.30”-0.80” total in 10- 30 minutes. WORST CASE SCENARIO: A slow-moving thunderstorm, training of thunderstorms cells or a large thunderstorm complex may result in up to 1.50” of rain in 30-60 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Douglas County 1 Current TO 1100 PM Current TO 1000 PM Adams County 1 Current TO 1100 PM Current TO 1000 PM Arvada 1 Current TO 1100 PM Current TO 1000 PM the City of Aurora 1 Current TO 1100 PM Current TO 1000 PM DIA 1 Current TO 1100 PM Current TO 1000 PM Arapahoe County 1 Current TO 1100 PM Current TO 1000 PM Denver County 1 Current TO 1100 PM Current TO 1000 PM Broomfield County 1 Current TO 1100 PM Current TO 1000 PM Jefferson County 1 Current TO 1100 PM Current TO 1000 PM Boulder County 1 Current TO 1100 PM Current TO 1000 PM Wheat Ridge 1 Current TO 1100 PM Current TO 1000 PM Lakewood 1 Current TO 1100 PM Current TO 1000 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 1100 PM SAT 0.05" (75%) to 0.3" (50%) to 0.8" (25%) ISSUED Arapahoe Current TO 1100 PM SAT 0.05" (75%) to 0.3" (50%) to 0.8" (25%) ISSUED Boulder Current TO 1100 PM SAT 0.05" (75%) to 0.3" (50%) to 0.8" (25%) ISSUED Broomfield Current TO 1100 PM SAT 0.05" (75%) to 0.3" (50%) to 0.8" (25%) ISSUED Denver Current TO 1100 PM SAT 0.05" (75%) to 0.3" (50%) to 0.8" (25%) ISSUED Douglas Current TO 1100 PM SAT 0.05" (75%) to 0.3" (50%) to 0.8" (25%) ISSUED Jefferson Current TO 1100 PM SAT 0.05" (75%) to 0.3" (50%) to 0.8" (25%) ISSUED Foothills above 6500ft       Boulder Current TO 1100 PM SAT 0.05" (90%) to 0.3" (60%) to 0.8" (30%) ISSUED Douglas Current TO 1100 PM SAT 0.05" (90%) to 0.3" (60%) to 0.8" (30%) ISSUED Jefferson Current TO 1100 PM SAT 0.05" (90%) to 0.3" (60%) to 0.8" (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]