Time: 1223 PM Sat August 6, 2022 Forecaster: Justin Brooks ------------------------- 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 valid 2pm until 9pm with prime time for heavy rainfall expected between 3pm and 8pm this evening. - Storms are starting to initiate along the higher terrain at this time and will continue over the next couple of hours before a weak disturbance moves into the District from the W/SW this afternoon between 2-3pm. This disturbance will bring a good chance for rain showers/thunderstorms across the District as dew points remain elevated in the mid to upper 50's. Storm motions will be from the W/SW to E/NE between 10-15mph, however, additional storms will likely form along outflow boundaries resulting in some slow moving and/or stationary storms this afternoon and early evening. The slow to stationary storms will bring the biggest threat for heavy rainfall, although with so much available moisture at the surface, most storms will be efficient rainfall producers. - A very slight chance storms could become severe this afternoon with wind gusts up to 60mph with hail around 1". Best chance for severe weather will be areas east of I-25 as storms strengthen onto the plains. One or two rounds of rain showers/thunderstorms will be possible with the first round likely having the best chance for a heavy rainfall threat at this time. A cold front will move through from the north through the overnight hours, effectively keeping a chance for scattered rain showers overnight and until daybreak Sunday. STORM RAINFALL POTENTIAL AND DURATION: Weak rain showers/thunderstorms will produce 0.1-0.4" in 10-30 minutes. Moderate to strong thunderstorms will have the potential to produce rainfall rates of 0.4-1.2" in 10-30 minutes. WORST CASE SCENARIO: A strong/slower moving or stationary thunderstorm may result in heavy rainfall rates of up to 2.8" in 45-75 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Boulder County 1 200 PM TO 900 PM 300 PM TO 800 PM Jefferson County 1 200 PM TO 900 PM 300 PM TO 800 PM Broomfield County 1 200 PM TO 900 PM 300 PM TO 800 PM Douglas County 1 200 PM TO 900 PM 300 PM TO 800 PM Adams County 1 200 PM TO 900 PM 300 PM TO 800 PM Denver County 1 200 PM TO 900 PM 300 PM TO 800 PM DIA 1 200 PM TO 900 PM 300 PM TO 800 PM Arapahoe County 1 200 PM TO 900 PM 300 PM TO 800 PM the City of Aurora 1 200 PM TO 900 PM 300 PM TO 800 PM Arvada 1 200 PM TO 900 PM 300 PM TO 800 PM Wheat Ridge 1 200 PM TO 900 PM 300 PM TO 800 PM Lakewood 1 200 PM TO 900 PM 300 PM TO 800 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 200 PM TO 900 PM 0.1" (80%) to 0.4" (50%) to 1.2" (25%) ISSUED Arapahoe 200 PM TO 900 PM 0.1" (80%) to 0.4" (50%) to 1.2" (25%) ISSUED Boulder 200 PM TO 900 PM 0.1" (80%) to 0.4" (50%) to 1.2" (25%) ISSUED Broomfield 200 PM TO 900 PM 0.1" (80%) to 0.4" (50%) to 1.2" (25%) ISSUED Denver 200 PM TO 900 PM 0.1" (80%) to 0.4" (50%) to 1.2" (25%) ISSUED Douglas 200 PM TO 900 PM 0.1" (80%) to 0.4" (50%) to 1.2" (25%) ISSUED Jefferson 200 PM TO 900 PM 0.1" (80%) to 0.4" (50%) to 1.2" (25%) ISSUED Foothills above 6500ft       Boulder 200 PM TO 900 PM 0.1" (90%) to 0.4" (60%) to 1.2" (30%) ISSUED Douglas 200 PM TO 900 PM 0.1" (90%) to 0.4" (60%) to 1.2" (30%) ISSUED Jefferson 200 PM TO 900 PM 0.1" (90%) to 0.4" (60%) to 1.2" (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]