Time: 949 PM Sat May 29, 2021 Forecaster: Brad Simmons ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1'S WILL BE EXTENDED UNTIL MIDNIGHT - Message 1's will be extended through midnight as thunderstorms are ongoing over southern areas of the District at this time and will have the potential to produce heavy rain should they intensify. - Current thunderstorm activity is limited to areas S of I-70 but may spread northward. Strong thunderstorms may also contain hail as well as moderate to brief heavy rain. - Message 1's may need to be extended beyond midnight if thunderstorm activity does not diminish in a timely fashion. STORM RAINFALL POTENTIAL AND DURATION: Weak to moderate thunderstorms will produce 0.1-0.3" in 10-30 minutes. Strong thunderstorms will have the potential to produce 0.3-0.8" in 10-30 minutes. WORST CASE SCENARIO: A stationary strong thunderstorm may result in up to 1.5" of rain in 45-60 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Boulder County 1 Current TO 1159 PM Current TO 1130 PM Jefferson County 1 Current TO 1159 PM Current TO 1130 PM Broomfield County 1 Current TO 1159 PM Current TO 1130 PM Douglas County 1 Current TO 1159 PM Current TO 1130 PM Adams County 1 Current TO 1159 PM Current TO 1130 PM Denver County 1 Current TO 1159 PM Current TO 1130 PM DIA 1 Current TO 1159 PM Current TO 1130 PM Arapahoe County 1 Current TO 1159 PM Current TO 1130 PM the City of Aurora 1 Current TO 1159 PM Current TO 1130 PM Arvada 1 Current TO 1159 PM Current TO 1130 PM Wheat Ridge 1 Current TO 1159 PM Current TO 1130 PM Lakewood 1 Current TO 1159 PM Current TO 1130 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 1159 PM SAT 0.1" (50%) to 0.3" (25%) to 0.8" (10%) ISSUED Arapahoe Current TO 1159 PM SAT 0.1" (80%) to 0.3" (50%) to 0.8" (15%) ISSUED Boulder Current TO 1159 PM SAT 0.1" (50%) to 0.3" (25%) to 0.8" (10%) ISSUED Broomfield Current TO 1159 PM SAT 0.1" (50%) to 0.3" (25%) to 0.8" (10%) ISSUED Denver Current TO 1159 PM SAT 0.1" (60%) to 0.3" (30%) to 0.8" (10%) ISSUED Douglas Current TO 1159 PM SAT 0.1" (90%) to 0.3" (60%) to 0.8" (20%) ISSUED Jefferson Current TO 1159 PM SAT 0.1" (60%) to 0.3" (30%) to 0.8" (10%) ISSUED Foothills above 6500ft       Boulder Current TO 1159 PM SAT 0.1" (50%) to 0.3" (25%) to 0.8" (10%) ISSUED Douglas Current TO 1159 PM SAT 0.1" (80%) to 0.3" (40%) to 0.8" (15%) ISSUED Jefferson Current TO 1159 PM SAT 0.1" (60%) to 0.3" (30%) to 0.8" (10%) 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]