Time: 324 PM Wed July 19, 2023 Forecaster: Justin Brooks ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1’S HAVE BEEN ISSUED FOR THE ENTIRE DISTRICT Message 1’s have been issued for the entire District and will be valid until 8:00 PM this evening. A potent, quick moving line of storms is approaching the District at this time with some pockets of heavy rainfall possible over the next couple of hours. The main threat with these cells will be a quick 0.5” in 10-15 minutes as storm movements remain fairly brisk between 20-30mph from west to east. A slight chance a few of these storms produce outflow boundaries, which could increase the threat of localized heavy rainfall as well. The best chance for storms will be from now through 8pm with a few lingering off and on showers possible into the late evening. These later storms will also be moving quickly from west to east between 20-30mph which should continue to help limit point rainfall amounts. STORM RAINFALL POTENTIAL AND DURATION: Weak thunderstorms will produce a 0.1-0.4” of rain. Moderate to strong thunderstorms will have the potential to produce rainfall rates of 0.4-1.0” in 10-30 minutes. WORST CASE SCENARIO: Training of moderate to strong thunderstorm cells may result in up to 1.6” of rain in 45-75 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Boulder County 1 Current TO 800 PM Current TO 700 PM Jefferson County 1 Current TO 800 PM Current TO 700 PM Broomfield County 1 Current TO 800 PM Current TO 700 PM Douglas County 1 Current TO 800 PM Current TO 700 PM Adams County 1 Current TO 800 PM Current TO 700 PM Denver County 1 Current TO 800 PM Current TO 700 PM DIA 1 Current TO 800 PM Current TO 700 PM Arapahoe County 1 Current TO 800 PM Current TO 700 PM the City of Aurora 1 Current TO 800 PM Current TO 700 PM Arvada 1 Current TO 800 PM Current TO 700 PM Wheat Ridge 1 Current TO 800 PM Current TO 700 PM Lakewood 1 Current TO 800 PM Current TO 700 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 800 PM WED 0.1" (60%) to 0.4" (30%) to 1" (15%) ISSUED Arapahoe Current TO 800 PM WED 0.1" (60%) to 0.4" (30%) to 1" (15%) ISSUED Boulder Current TO 800 PM WED 0.1" (60%) to 0.4" (30%) to 1" (15%) ISSUED Broomfield Current TO 800 PM WED 0.1" (60%) to 0.4" (30%) to 1" (15%) ISSUED Denver Current TO 800 PM WED 0.1" (60%) to 0.4" (30%) to 1" (15%) ISSUED Douglas Current TO 800 PM WED 0.1" (60%) to 0.4" (30%) to 1" (15%) ISSUED Jefferson Current TO 800 PM WED 0.1" (60%) to 0.4" (30%) to 1" (15%) ISSUED Foothills above 6500ft       Boulder Current TO 800 PM WED 0.1" (60%) to 0.4" (30%) to 1" (15%) ISSUED Douglas Current TO 800 PM WED 0.1" (60%) to 0.4" (30%) to 1" (15%) ISSUED Jefferson Current TO 800 PM WED 0.1" (60%) to 0.4" (30%) to 1" (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]