Time: 208 PM Thu September 15, 2022 Forecaster: Brad Simmons ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1'S ISSUED FOR THE ENTIRE DISTRICT - Message 1's have been issued for the entire District and will be valid until 8:00 PM this evening. - An upper-level disturbance, rich with moisture from the remnants of tropical cyclone Kay, is propagating across the state this afternoon creating a favorable environment for scattered showers and thunderstorms across the District into the evening. Typical storms will produce brief moderate rainfall but stronger storms or training of thunderstorm cells will have the potential to produce small areas of heavy rainfall, hail, and gusty winds. - Prime time for thunderstorm activity will be starting over the next hour and continue through about 7:30 PM. Favored areas for stronger storms appears to be E of I-25 and S of I-70. Thunderstorms are expected to have pushed east of the District by 8:00 PM or shortly after. STORM RAINFALL POTENTIAL AND DURATION: Weak thunderstorms will produce 0.1-0.4" of rain. Moderate to strong thunderstorms will have the potential to produce rainfall rates of 0.4-1.0" in 10-30 minutes. WORST CASE SCENARIO: A slower moving strong thunderstorm or training of thunderstorm cells has the potential to produce up to 1.6" of rain in 45-60 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Boulder County 1 200 PM TO 800 PM 230 PM TO 730 PM Jefferson County 1 200 PM TO 800 PM 230 PM TO 730 PM Broomfield County 1 200 PM TO 800 PM 230 PM TO 730 PM Douglas County 1 200 PM TO 800 PM 230 PM TO 730 PM Adams County 1 200 PM TO 800 PM 230 PM TO 730 PM Denver County 1 200 PM TO 800 PM 230 PM TO 730 PM DIA 1 200 PM TO 800 PM 230 PM TO 730 PM Arapahoe County 1 200 PM TO 800 PM 230 PM TO 730 PM the City of Aurora 1 200 PM TO 800 PM 230 PM TO 730 PM Arvada 1 200 PM TO 800 PM 230 PM TO 730 PM Wheat Ridge 1 200 PM TO 800 PM 230 PM TO 730 PM Lakewood 1 200 PM TO 800 PM 230 PM TO 730 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 800 PM THU 0.1" (75%) to 0.4" (30%) to 1.0" (10%) ISSUED Arapahoe Current TO 800 PM THU 0.1" (90%) to 0.4" (50%) to 1.0" (20%) ISSUED Boulder Current TO 800 PM THU 0.1" (75%) to 0.4" (30%) to 1.0" (10%) ISSUED Broomfield Current TO 800 PM THU 0.1" (75%) to 0.4" (30%) to 1.0" (10%) ISSUED Denver Current TO 800 PM THU 0.1" (80%) to 0.4" (40%) to 1.0" (15%) ISSUED Douglas Current TO 800 PM THU 0.1" (90%) to 0.4" (50%) to 1.0" (20%) ISSUED Jefferson Current TO 800 PM THU 0.1" (80%) to 0.4" (40%) to 1.0" (15%) ISSUED Foothills above 6500ft       Boulder Current TO 800 PM THU 0.1" (80%) to 0.4" (40%) to 1.0" (15%) ISSUED Douglas Current TO 800 PM THU 0.1" (90%) to 0.4" (50%) to 1.0" (20%) ISSUED Jefferson Current TO 800 PM THU 0.1" (90%) to 0.4" (50%) to 1.0" (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]