Time: 616 PM Wed May 31, 2023 Forecaster: Justin Brooks ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1'S CONTINUE VALID Message 1’s will continue valid until 10pm as the threat of heavy rain remains into this evening. An explosive round of thunderstorms impacted parts of the District this afternoon and have since moved N/NE and out of the District. These storms contained lots of hail, rather than heavy rainfall with very gusty winds resulting in a few severe thunderstorms. A couple of gust fronts continue to initiate storms relatively close to the eastern edge of the District and these storms could trend into the District into the later evening. As we move closer to nightfall, the chances for explosive development leading to hail will diminish, however, the chance for moderate to heavy rainfall will likely persist into the evening. The best chance for additional storms will be from now through 10pm with lingering showers possible through midnight. Storm motions continue to be from south to north, between 5-10mph, with some erratic storm movement off gust fronts possible through the rest of the evening. Skies will gradually clear after midnight with overnight lows dropping to into the low 50’s. STORM RAINFALL POTENTIAL AND DURATION: Weak to moderate thunderstorms will produce TR-0.25” of rain in 10-30 minutes. Strong thunderstorms will have the potential to produce rainfallrates of 0.25-0.75" in 10-30 minutes. WORST CASE SCENARIO: A nearly stationary strong thunderstorm may result in up to 1.25” of rain in 45-75 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME the City of Aurora 1 Current TO 1000 PM Current TO 900 PM Arapahoe County 1 Current TO 1000 PM Current TO 900 PM DIA 1 Current TO 1000 PM Current TO 900 PM Denver County 1 Current TO 1000 PM Current TO 900 PM Adams County 1 Current TO 1000 PM Current TO 900 PM Douglas County 1 Current TO 1000 PM Current TO 900 PM Broomfield County 1 Current TO 1000 PM Current TO 900 PM Jefferson County 1 Current TO 1000 PM Current TO 900 PM Boulder County 1 Current TO 1000 PM Current TO 900 PM Arvada 1 Current TO 1000 PM Current TO 900 PM Wheat Ridge 1 Current TO 1000 PM Current TO 900 PM Lakewood 1 Current TO 1000 PM Current TO 900 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 1000 PM WED Trace (50%) to 0.25" (25%) to 0.75" (10%) ISSUED Arapahoe Current TO 1000 PM WED Trace (50%) to 0.25" (25%) to 0.75" (10%) ISSUED Boulder Current TO 1000 PM WED Trace (50%) to 0.25" (25%) to 0.75" (10%) ISSUED Broomfield Current TO 1000 PM WED Trace (50%) to 0.25" (25%) to 0.75" (10%) ISSUED Denver Current TO 1000 PM WED Trace (50%) to 0.25" (25%) to 0.75" (10%) ISSUED Douglas Current TO 1000 PM WED Trace (50%) to 0.25" (25%) to 0.75" (10%) ISSUED Jefferson Current TO 1000 PM WED Trace (50%) to 0.25" (25%) to 0.75" (10%) ISSUED Foothills above 6500ft       Boulder Current TO 1000 PM WED Trace (60%) to 0.25" (30%) to 0.75" (15%) ISSUED Douglas Current TO 1000 PM WED Trace (60%) to 0.25" (30%) to 0.75" (15%) ISSUED Jefferson Current TO 1000 PM WED Trace (60%) to 0.25" (30%) to 0.75" (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]