Time: 426 PM Sat May 15, 2021 Forecaster: Brad Simmons ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1'S ISSUED FOR REMAINDER OF THE DISTRICT - Message 1's have been issued for the remaining areas of the District and will be valid until 9:00pm. A convergence line currently stretches from Jefferson County through the central portions of the District and is expected to act as a focus for additional thunderstorm development into this evening. - Thunderstorms that develop will have the potential to produce brief heavy rainfall that may lead to excessive runoff and street flooding. Hail and gusty winds may also accompany the stronger thunderstorm cells. Best chances for thunderstorm activity is expected to be through sunset. - Storm motions will generally be from west to east at 15-20mph. Stronger thunderstorms may anchor briefly or have erratic storm movements at times due to outflow boundaries/gust fronts. STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers and weak thunderstorms will produce a 0.1-0.3" of rain. Moderate to strong thunderstorms will have the potential to produce 0.3-0.8" in 10-30 minutes. WORST CASE SCENARIO: A stalled out thunderstorm along an outflow boundary may result in up to 1.6" of rain in 60 minutes or less. COUNTY MESSAGE VALID TIMES PRIME TIME 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 Lakewood 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 County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 900 PM SAT 0.1" (90%) to 0.3" (60%) to 0.8" (20%) ISSUED Arapahoe Current TO 900 PM SAT 0.1" (90%) to 0.3" (60%) to 0.8" (20%) ISSUED Boulder Current TO 900 PM SAT 0.1" (90%) to 0.3" (60%) to 0.8" (20%) ISSUED Broomfield Current TO 900 PM SAT 0.1" (90%) to 0.3" (60%) to 0.8" (20%) ISSUED Denver Current TO 900 PM SAT 0.1" (90%) to 0.3" (60%) to 0.8" (20%) ISSUED Douglas Current TO 900 PM SAT 0.1" (90%) to 0.3" (60%) to 0.8" (20%) ISSUED Jefferson Current TO 900 PM SAT 0.1" (90%) to 0.3" (60%) to 0.8" (20%) ISSUED Foothills above 6500ft       Boulder Current TO 900 PM SAT 0.1" (90%) to 0.3" (60%) to 0.8" (20%) ISSUED Douglas Current TO 900 PM SAT 0.1" (90%) to 0.3" (60%) to 0.8" (20%) ISSUED Jefferson Current TO 900 PM SAT 0.1" (90%) to 0.3" (60%) to 0.8" (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]