Time: 543 PM Fri June 30, 2023 Forecaster: Justin Brooks ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1’S WILL BE ALLOWED TO EXPIRE AT 6PM Message 1’s will expire at 6pm as the threat of heavy rainfall has come to an end. Showers and thunderstorms have moved south and eastward and out of the District at this time. Sunny to partly sunny skies currently with temperatures in the low to mid 60’s. A few showers/isolated thunderstorms persist to the north and northwest and could impact the District later this evening. The best chance for additional storm development between 7-9pm with a few lighter showers possibly lingering though 10pm. Upper-level winds will shift westerly to northwesterly through the rest of the evening which should keep down sloping winds, keeping a minimal chance for additional shower activity. Low to mid 50’s dew points at the surface will likely keep at least a LOW threat for Message 1’s to be reissued this evening, however the threat for that should be minimal at this time. STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers/isolated thunderstorms will produce trace-0.20” total, in 10-30 minutes. A moderate thunderstorm could produce 0.20-0.60” total, in 10-30 minutes. WORST CASE SCENARIO: A slower moving thunderstorm, or training of thunderstorm cells has the potential to produce up to 1.2” in 45-60 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME the City of Aurora 1 Current TO 600 PM Current TO 600 PM Arapahoe County 1 Current TO 600 PM Current TO 600 PM DIA 1 Current TO 600 PM Current TO 600 PM Denver County 1 Current TO 600 PM Current TO 600 PM Adams County 1 Current TO 600 PM Current TO 600 PM Douglas County 1 Current TO 600 PM Current TO 600 PM Broomfield County 1 Current TO 600 PM Current TO 600 PM Jefferson County 1 Current TO 600 PM Current TO 600 PM Boulder County 1 Current TO 600 PM Current TO 600 PM Arvada 1 Current TO 600 PM Current TO 600 PM Wheat Ridge 1 Current TO 600 PM Current TO 600 PM Lakewood 1 Current TO 600 PM Current TO 600 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 1000 PM FRI Trace (40%) to 0.2" (20%) to 0.6" (10%) LOW Arapahoe Current TO 1000 PM FRI Trace (40%) to 0.2" (20%) to 0.6" (10%) LOW Boulder Current TO 1000 PM FRI Trace (40%) to 0.2" (20%) to 0.6" (10%) LOW Broomfield Current TO 1000 PM FRI Trace (40%) to 0.2" (20%) to 0.6" (10%) LOW Denver Current TO 1000 PM FRI Trace (40%) to 0.2" (20%) to 0.6" (10%) LOW Douglas Current TO 1000 PM FRI Trace (40%) to 0.2" (20%) to 0.6" (10%) LOW Jefferson Current TO 1000 PM FRI Trace (40%) to 0.2" (20%) to 0.6" (10%) LOW Foothills above 6500ft       Boulder Current TO 1000 PM FRI Trace (50%) to 0.2" (25%) to 0.6" (15%) LOW Douglas Current TO 1000 PM FRI Trace (50%) to 0.2" (25%) to 0.6" (15%) LOW Jefferson Current TO 1000 PM FRI Trace (50%) to 0.2" (25%) to 0.6" (15%) LOW MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS. MHFD Flood Prediction Center: 303-458-0789    F2P2 Website [http://udfcd.org/Flash+Flood+Prediction+Program]