Flash Flood Prediction Program

Time: 910 PM Wed June 30, 2021 Forecaster: Justin Brooks ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1'S WILL BE ALLOWED TO EXPIRE AT 10:00 PM - Message 1's will be allowed to expire at 10:00pm as the threat for heavy rainfall has ended for the day. - A weak disturbance upstream is expected to produce additional widely scattered light rain showers through about midnight, likely favoring areas W of I-25 and over the foothills. Beyond midnight there could be a few lingering, isolated showers that persist into the overnight. Showers will move from W to E between 5-10mph. Although unlikely, if a weak thunderstorm were to develop it would be capable of producing brief moderate to heavy rainfall. - Overnight lows will drop into the mid to upper 50's with a few lingering rain showers likely out on the eastern plains through daybreak Thursday. Storm chances increase tomorrow with another good chance for heavy rainfall as an abundance of moisture remains in place along with slow to nearly stationary storm movements. STORM RAINFALL POTENTIAL AND DURATION: Rainfall rates from light rain showers will generally range from a trace to 0.2" in 30-60 minutes with moderate rain showers producing rainfall rates of 0.2-0.5" in 30-60 minutes. WORST CASE SCENARIO: Weak to moderate thunderstorms are able to develop with the potential to produce brief heavy rainfall of 0.3-0.9" in 10-30 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Boulder County 1 Current TO 1000 PM Current TO 930 PM Jefferson County 1 Current TO 1000 PM Current TO 930 PM Broomfield County 1 Current TO 1000 PM Current TO 930 PM Douglas County 1 Current TO 1000 PM Current TO 930 PM Adams County 1 Current TO 1000 PM Current TO 930 PM Denver County 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 the City of Aurora 1 Current TO 1000 PM Current TO 930 PM Arvada 1 Current TO 1000 PM Current TO 930 PM Wheat Ridge 1 Current TO 1000 PM Current TO 930 PM Lakewood 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 600 AM THU Trace (40%) to 0.2" (20%) to 0.5" (5%) NONE Arapahoe Current TO 600 AM THU Trace (40%) to 0.2" (20%) to 0.5" (5%) NONE Boulder Current TO 600 AM THU Trace (40%) to 0.2" (20%) to 0.5" (5%) NONE Broomfield Current TO 600 AM THU Trace (40%) to 0.2" (20%) to 0.5" (5%) NONE Denver Current TO 600 AM THU Trace (40%) to 0.2" (20%) to 0.5" (5%) NONE Douglas Current TO 600 AM THU Trace (40%) to 0.2" (20%) to 0.5" (5%) NONE Jefferson Current TO 600 AM THU Trace (40%) to 0.2" (20%) to 0.5" (5%) NONE Foothills above 6500ft       Boulder Current TO 600 AM THU Trace (50%) to 0.2" (25%) to 0.5" (10%) LOW Douglas Current TO 600 AM THU Trace (50%) to 0.2" (25%) to 0.5" (10%) LOW Jefferson Current TO 600 AM THU Trace (50%) to 0.2" (25%) to 0.5" (10%) 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]