Flash Flood Prediction Program

Time: 610 PM Fri July 2, 2021 Forecaster: Brad Simmons ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1'S CONTINUE VALID FOR THE ENTIRE DISTRICT - Message 1's will continue valid over the entire District through 9:00pm this evening. - Moderate to strong thunderstorms are currently just to the NW and SW of the District currently. Thunderstorms should they develop over the next few hours will have the potential to produce heavy rainfall as ample surface moisture in is place with dew points currently in the 57-61 range. - Surface temperatures have peaked and the strength of potential storms is now a little lower than had storms developed during hours of maximum heating. Upper level steering winds are from NW to SE at around 10mph. Best chances for thunderstorm activity is through 8:30pm. STORM RAINFALL POTENTIAL AND DURATION: Weak thunderstorms will produce 0.1-0.4" of rain in 10-30 minutes. Moderate to strong thunderstorms will have the potential to produce heavy rainfall rates of 0.4-1.2" in 10-30 minutes WORST CASE SCENARIO: Training of thunderstorm cells or a large slow moving strong thunderstorm may result in very heavy rainfall of up to 2.4" in 45-75 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Boulder County 1 Current TO 900 PM Current TO 830 PM Jefferson County 1 Current TO 900 PM Current TO 830 PM Broomfield County 1 Current TO 900 PM Current TO 830 PM Douglas County 1 Current TO 900 PM Current TO 830 PM Adams County 1 Current TO 900 PM Current TO 830 PM Denver County 1 Current TO 900 PM Current TO 830 PM DIA 1 Current TO 900 PM Current TO 830 PM Arapahoe County 1 Current TO 900 PM Current TO 830 PM the City of Aurora 1 Current TO 900 PM Current TO 830 PM Arvada 1 Current TO 900 PM Current TO 830 PM Wheat Ridge 1 Current TO 900 PM Current TO 830 PM Lakewood 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 FRI Trace (75%) to 0.4" (40%) to 1.2" (10%) ISSUED Arapahoe Current TO 900 PM FRI Trace (75%) to 0.4" (40%) to 1.2" (10%) ISSUED Boulder Current TO 900 PM FRI Trace (100%) to 0.4" (60%) to 1.2" (20%) ISSUED Broomfield Current TO 900 PM FRI Trace (85%) to 0.4" (50%) to 1.2" (15%) ISSUED Denver Current TO 900 PM FRI Trace (75%) to 0.4" (40%) to 1.2" (10%) ISSUED Douglas Current TO 900 PM FRI Trace (100%) to 0.4" (60%) to 1.2" (20%) ISSUED Jefferson Current TO 900 PM FRI Trace (95%) to 0.4" (55%) to 1.2" (15%) ISSUED Foothills above 6500ft       Boulder Current TO 900 PM FRI Trace (100%) to 0.4" (60%) to 1.2" (20%) ISSUED Douglas Current TO 900 PM FRI Trace (100%) to 0.4" (60%) to 1.2" (20%) ISSUED Jefferson Current TO 900 PM FRI Trace (100%) to 0.4" (60%) to 1.2" (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]