Time: 132 PM Mon August 28, 2023 Forecaster: Justin Brooks ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1’S HAVE BEEN ISSUED EFFECTIVE UNTIL 10:00 PM Message 1’s have been issued effective until 10pm as there is a threat of heavy rainfall this afternoon and evening. A few storms have formed along the foothills and will begin moving onto the plains over the next hour or so. A few rounds of showers/thunderstorms will be possible with the last round likely tapering off by 10pm. The largest threat for storms today will be a quick 0.5” in 10-15 minutes, with a low threat for any rainfall over an inch and hour as most storms move rather quickly between 15-25mph. These quick NW to SE storm motions should help limit point rainfall amounts, however, a stronger storm has the potential to produce a gust front resulting in additional, erratic storm development throughout the District. Skies will clear relatively fast behind the final round of showers with mild and dry conditions expected through the overnight. STORM RAINFALL POTENTIAL AND DURATION: Typical showers will produce rainfall of 0.05" to 0.25” total in 10-30 minutes. Moderate to strong showers have the potential to produce rainfall of 0.25 to 0.75” total in 10-30 minutes. WORST CASE SCENARIO: Strong stationery, or training of thunderstorms has the potential to produce 0.75” to 1.50” in under 60 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Denver County 1 Current TO 1000 PM Current TO 930 PM Adams County 1 Current TO 1000 PM Current TO 930 PM Douglas County 1 Current TO 1000 PM Current TO 930 PM Lakewood 1 Current TO 1000 PM Current TO 930 PM Wheat Ridge 1 Current TO 1000 PM Current TO 930 PM Arvada 1 Current TO 1000 PM Current TO 930 PM the City of Aurora 1 Current TO 1000 PM Current TO 930 PM DIA 1 Current TO 1000 PM Current TO 930 PM Arapahoe County 1 Current TO 1000 PM Current TO 930 PM Broomfield County 1 Current TO 1000 PM Current TO 930 PM Jefferson County 1 Current TO 1000 PM Current TO 930 PM Boulder County 1 Current TO 1000 PM Current TO 930 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 1000 PM MON 0.05" (75%) to 0.25" (50%) to 0.75" (25%) ISSUED Arapahoe Current TO 1000 PM MON 0.05" (75%) to 0.25" (50%) to 0.75" (25%) ISSUED Boulder Current TO 1000 PM MON 0.05" (75%) to 0.25" (50%) to 0.75" (25%) ISSUED Broomfield Current TO 1000 PM MON 0.05" (75%) to 0.25" (50%) to 0.75" (25%) ISSUED Denver Current TO 1000 PM MON 0.05" (75%) to 0.25" (50%) to 0.75" (25%) ISSUED Douglas Current TO 1000 PM MON 0.05" (75%) to 0.25" (50%) to 0.75" (25%) ISSUED Jefferson Current TO 1000 PM MON 0.05" (75%) to 0.25" (50%) to 0.75" (25%) ISSUED Foothills above 6500ft       Boulder Current TO 1000 PM MON 0.05" (80%) to 0.25" (60%) to 0.75" (30%) ISSUED Douglas Current TO 1000 PM MON 0.05" (80%) to 0.25" (60%) to 0.75" (30%) ISSUED Jefferson Current TO 1000 PM MON 0.05" (80%) to 0.25" (60%) to 0.75" (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]