Time: 900 PM Sat July 31, 2021 Forecaster: Brad Simmons ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 2'S WILL BE ALLOWED TO EXPIRE AT 9PM - Message 2's will be allowed to expire at 9:00pm as the threat for heavy rainfall over the District has ended. All previous Message 1 LIF's have also expired or will expire at 9:00pm. Now that temperatures are in the 60's precipitation will favor light to briefly moderate rain showers. - Rain showers will continue possible well into the evening eventually ending from N to S. By around midnight generally dry conditions are expected into Sunday morning. - Light rain showers this evening may produce minor runoff, excessive runoff is no longer anticipated. STORM RAINFALL POTENTIAL AND DURATION: Rain showers will produce a trace to 0.3" in 30-60 minutes. WORST CASE SCENARIO: A weak thunderstorm is able to develop with the potential to produce 0.4-1.2" of heavy rain in 10-30 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Lakewood 2 Current TO 900 PM Current TO 900 PM Wheat Ridge 2 Current TO 900 PM Current TO 900 PM Arvada 2 Current TO 900 PM Current TO 900 PM the City of Aurora 2 Current TO 900 PM Current TO 900 PM DIA 2 Current TO 900 PM Current TO 900 PM Arapahoe County 2 Current TO 900 PM Current TO 900 PM Denver County 2 Current TO 900 PM Current TO 900 PM Jefferson County 2 Current TO 900 PM Current TO 900 PM Broomfield County 2 Current TO 900 PM Current TO 900 PM Douglas County 2 Current TO 900 PM Current TO 900 PM Adams County 2 Current TO 900 PM Current TO 900 PM Boulder County 2 Current TO 900 PM Current TO 900 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 60-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 1159 PM SAT Trace (60%) to 0.1" (30%) to 0.3" (15%) ISSUED Arapahoe Current TO 1159 PM SAT Trace (100%) to 0.1" (75%) to 0.3" (40%) ISSUED Boulder Current TO 1159 PM SAT Trace (40%) to 0.1" (20%) to 0.3" (5%) ISSUED Broomfield Current TO 1159 PM SAT Trace (50%) to 0.1" (25%) to 0.3" (10%) ISSUED Denver Current TO 1159 PM SAT Trace (80%) to 0.1" (60%) to 0.3" (30%) ISSUED Douglas Current TO 1159 PM SAT Trace (100%) to 0.1" (75%) to 0.3" (40%) ISSUED Jefferson Current TO 1159 PM SAT Trace (80%) to 0.1" (60%) to 0.3" (30%) ISSUED Foothills above 6500ft       Boulder Current TO 1159 PM SAT Trace (40%) to 0.1" (20%) to 0.3" (5%) ISSUED Douglas Current TO 1159 PM SAT Trace (100%) to 0.1" (75%) to 0.3" (40%) ISSUED Jefferson Current TO 1159 PM SAT Trace (60%) to 0.1" (30%) to 0.3" (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]