Time: 849 PM Sun August 6, 2023 Forecaster: Justin Brooks ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1’S WILL BE ALLOWED TO EXPIRE AT 9:00 PM Message 1’s will be allowed to expire at 9pm as the threat of heavy rain has come to an end. Stronger storms that impacted the District this afternoon have moved well east at this time. A few showers/isolated thunderstorms persist, which will keep a continued chance for showers through midnight. Storm motions continue to be brisk from west to east, between 20-30mph which will also limit point rainfall amounts. Skies will gradually clear through the rest of the overnight with clear skies likely by daybreak tomorrow. Mild and dry conditions expected through the overnight as low temperatures drop into the mid to upper 50’s on the plains with low 50’s along the foothills. STORM RAINFALL POTENTIAL AND DURATION: Typical showers will produce a trace to 0.20” total in 10-30 minutes. A weak to moderate thunderstorm will produce 0.20-0.40” total in 10-30 minutes. WORST CASE SCENARIO: A strong thunderstorm, or training of showers/thunderstorm cells has the potential to produce up to 0.8” in under 60 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Boulder County 1 Current TO 900 PM Current TO 900 PM Jefferson County 1 Current TO 900 PM Current TO 900 PM Broomfield County 1 Current TO 900 PM Current TO 900 PM Douglas County 1 Current TO 900 PM Current TO 900 PM Adams County 1 Current TO 900 PM Current TO 900 PM Denver County 1 Current TO 900 PM Current TO 900 PM DIA 1 Current TO 900 PM Current TO 900 PM Arapahoe County 1 Current TO 900 PM Current TO 900 PM the City of Aurora 1 Current TO 900 PM Current TO 900 PM Arvada 1 Current TO 900 PM Current TO 900 PM Wheat Ridge 1 Current TO 900 PM Current TO 900 PM Lakewood 1 Current TO 900 PM Current TO 900 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 900 PM SUN Trace (30%) to 0.2" (15%) to 0.4" (5%) NONE Arapahoe Current TO 900 PM SUN Trace (50%) to 0.2" (25%) to 0.4" (10%) NONE Boulder Current TO 900 PM SUN Trace (30%) to 0.2" (15%) to 0.4" (5%) NONE Broomfield Current TO 900 PM SUN Trace (30%) to 0.2" (15%) to 0.4" (5%) NONE Denver Current TO 900 PM SUN Trace (50%) to 0.2" (25%) to 0.4" (10%) NONE Douglas Current TO 900 PM SUN Trace (50%) to 0.2" (25%) to 0.4" (10%) NONE Jefferson Current TO 900 PM SUN Trace (50%) to 0.2" (25%) to 0.4" (10%) NONE Foothills above 6500ft       Boulder Current TO 900 PM SUN Trace (50%) to 0.2" (25%) to 0.4" (10%) NONE Douglas Current TO 900 PM SUN Trace (50%) to 0.2" (25%) to 0.4" (10%) NONE Jefferson Current TO 900 PM SUN Trace (50%) to 0.2" (25%) to 0.4" (10%) NONE MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS. MHFD Flood Prediction Center: 303-458-0789    F2P2 Website [http://udfcd.org/Flash+Flood+Prediction+Program]