Time: 906 PM Sun August 27, 2023 Forecaster: Justin Brooks ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1’S HAVE BEEN EXTENDED UNTIL 11:00 PM AS THE THREAT FOR HEAVY RAIN CONTINUES Message 1’s will be extended until 11:00pm as the threat of heavy rainfall continues. Another round of showers/isolated thunderstorms will move through the District from the NW to SE over the next couple of hours bringing some additional rainfall across most of the District. These storms are moving between 10-20mph which is limiting point rainfall amounts. However, with dew points in the upper 50’s to low 60’s, a stalled shower, or moderate to strong thunderstorm will have the potential to produce a quick 0.4-0.6” in 10-30 minutes. Typical showers/isolated thunderstorms will produce between 0.05-0.25” total rainfall, with a few pockets that could produce isolated higher amounts. A chance for off and on showers will persist through the overnight with any shower activity coming to an end between 2-3am. Skies will gradually clear through the rest of the overnight as lows decrease into the low to mid 60s. Very little overall chance for tomorrow with another chance for storms by midday, with similar NW to SE storm motions. STORM RAINFALL POTENTIAL AND DURATION: Typical showers/isolated thunderstorms will produce a 0.05-0.25” total in 10-30 minutes. A moderate to strong shower/thunderstorm will produce 0.25-0.60” total in 10-30 minutes. WORST CASE SCENARIO: A strong thunderstorm, or training of thunderstorm cells has the potential to produce 0.60-1.20” in under 60 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Lakewood 1 Current TO 1100 PM Current TO 1030 PM Wheat Ridge 1 Current TO 1100 PM Current TO 1030 PM Arvada 1 Current TO 1100 PM Current TO 1030 PM the City of Aurora 1 Current TO 1100 PM Current TO 1030 PM Arapahoe County 1 Current TO 1100 PM Current TO 1030 PM DIA 1 Current TO 1100 PM Current TO 1030 PM Denver County 1 Current TO 1100 PM Current TO 1030 PM Adams County 1 Current TO 1100 PM Current TO 1030 PM Douglas County 1 Current TO 1100 PM Current TO 1030 PM Broomfield County 1 Current TO 1100 PM Current TO 1030 PM Jefferson County 1 Current TO 1100 PM Current TO 1030 PM Boulder County 1 Current TO 1100 PM Current TO 1030 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 1100 PM SUN 0.05" (50%) to 0.25" (30%) to 0.6" (15%) ISSUED Arapahoe Current TO 1100 PM SUN 0.05" (50%) to 0.25" (30%) to 0.6" (15%) ISSUED Boulder Current TO 1100 PM SUN 0.05" (50%) to 0.25" (30%) to 0.6" (15%) ISSUED Broomfield Current TO 1100 PM SUN 0.05" (50%) to 0.25" (30%) to 0.6" (15%) ISSUED Denver Current TO 1100 PM SUN 0.05" (50%) to 0.25" (30%) to 0.6" (15%) ISSUED Douglas Current TO 1100 PM SUN 0.05" (50%) to 0.25" (30%) to 0.6" (15%) ISSUED Jefferson Current TO 1100 PM SUN 0.05" (50%) to 0.25" (30%) to 0.6" (15%) ISSUED Foothills above 6500ft       Boulder Current TO 1100 PM SUN 0.05" (50%) to 0.25" (30%) to 0.6" (15%) ISSUED Douglas Current TO 1100 PM SUN 0.05" (50%) to 0.25" (30%) to 0.6" (15%) ISSUED Jefferson Current TO 1100 PM SUN 0.05" (50%) to 0.25" (30%) to 0.6" (15%) 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]