Flash Flood Prediction Program

Time: 438 PM Thu August 8, 2024 Forecaster: Justin Brooks ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1’S HAVE BEEN ISSUED EFFECTIVE UNTIL 9:00 PM Cooler temperatures have limited most storm development today. However, a stronger line of storms has initiated along the foothills this afternoon and will likely move into the District over the next hour or so. Dew points in the upper 50s to around 60, along with model driven PWAT values between 1.00-1.10” will result in efficient rainfall producing storms this afternoon and early evening. Currently storms will be moving from NW to SE around 15mph, with anchored storms possibly forming along outflow boundaries. These anchored/slow-moving storms will result in the potential for both 0.50” in 10-20 minutes and due to PWAT values above an inch, could result in an isolated 1.00-1.50” in under 60 minutes is storms linger, or there is training of storm cells. Once these rounds move out, skies will gradually clear through the late evening and overnight with temperatures dropping into the upper 50s for the plains with low to mid 50s along the foothills. STORM RAINFALL POTENTIAL AND DURATION: Typical showers will produce a trace-0.25" total in 10-30 minutes. A moderate to strong thunderstorm will produce rainfall rates of 0.25”-0.75” 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 Lakewood 1 Current TO 900 PM Current TO 830 PM Wheat Ridge 1 Current TO 900 PM Current TO 830 PM Arvada 1 Current TO 900 PM Current TO 830 PM the City of Aurora 1 Current TO 900 PM Current TO 830 PM Arapahoe County 1 Current TO 900 PM Current TO 830 PM DIA 1 Current TO 900 PM Current TO 830 PM Denver County 1 Current TO 900 PM Current TO 830 PM Adams County 1 Current TO 900 PM Current TO 830 PM Douglas County 1 Current TO 900 PM Current TO 830 PM Broomfield County 1 Current TO 900 PM Current TO 830 PM Jefferson County 1 Current TO 900 PM Current TO 830 PM Boulder County 1 Current TO 900 PM Current TO 830 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 900 PM THU Trace (80%) to 0.25" (40%) to 0.75" (20%) ISSUED Arapahoe Current TO 900 PM THU Trace (80%) to 0.25" (40%) to 0.75" (20%) ISSUED Boulder Current TO 900 PM THU Trace (80%) to 0.25" (40%) to 0.75" (20%) ISSUED Broomfield Current TO 900 PM THU Trace (80%) to 0.25" (40%) to 0.75" (20%) ISSUED Denver Current TO 900 PM THU Trace (80%) to 0.25" (40%) to 0.75" (20%) ISSUED Douglas Current TO 900 PM THU Trace (80%) to 0.25" (40%) to 0.75" (20%) ISSUED Jefferson Current TO 900 PM THU Trace (80%) to 0.25" (40%) to 0.75" (20%) ISSUED Foothills above 6500ft       Boulder Current TO 900 PM THU Trace (80%) to 0.25" (50%) to 0.75" (30%) ISSUED Douglas Current TO 900 PM THU Trace (80%) to 0.25" (50%) to 0.75" (30%) ISSUED Jefferson Current TO 900 PM THU Trace (80%) to 0.25" (50%) to 0.75" (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]