Flash Flood Prediction Program

Time: 634 PM Sat July 20, 2024 Forecaster: Aaron O ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1’S HAVE BEEN ISSUED EFFECTIVE UNTIL 11:00 PM A gust front is currently approaching the District from the northeast and pulsing up thunderstorms in its wake. This gust front will move all the way through the District and push into the foothills allowing the chance of thunderstorms within the District during the evening hours. Storms that do develop will contain moderate to brief heavy rainfall. Storm motions will be moving NNW to SSE at 20-25 mph, which should limit point rainfall amounts. Stronger storms will produce outflow boundaries and could cause erratic movement, lower speeds, increasing point rainfall amounts for the District. The biggest threat will be this evening will be a quick 0.50-1.00” total in 10-30 minutes rather than any long lasting rainfall. Additional showers could impact the region overnight, keeping lows around 60 for the plains and around 50 for the foothills be daybreak tomorrow. STORM RAINFALL POTENTIAL AND DURATION: Typical showers thunderstorms today will produce 0.25"-0.50” in 10-30 minutes. Stronger/slower moving storms will produce up to 1.00" in 10-30 minutes. WORST CASE SCENARIO: A strong/stationary thunderstorm, or training of thunderstorms, may be capable of producing up to 1.50” or more in 30 minutes or less. COUNTY MESSAGE VALID TIMES PRIME TIME Arvada 1 Current TO 1100 PM 700 PM TO 1000 PM the City of Aurora 1 Current TO 1100 PM 700 PM TO 1000 PM Arapahoe County 1 Current TO 1100 PM 700 PM TO 1000 PM DIA 1 Current TO 1100 PM 700 PM TO 1000 PM Denver County 1 Current TO 1100 PM 700 PM TO 1000 PM Douglas County 1 Current TO 1100 PM 700 PM TO 1000 PM Adams County 1 Current TO 1100 PM 700 PM TO 1000 PM Broomfield County 1 Current TO 1100 PM 700 PM TO 1000 PM Jefferson County 1 Current TO 1100 PM 700 PM TO 1000 PM Boulder County 1 Current TO 1100 PM 700 PM TO 1000 PM Wheat Ridge 1 Current TO 1100 PM 700 PM TO 1000 PM Lakewood 1 Current TO 1100 PM 700 PM TO 1000 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 1100 PM SAT 0.3" (60%) to 0.5" (40%) to 1" (20%) ISSUED Arapahoe Current TO 1100 PM SAT 0.3" (60%) to 0.5" (40%) to 1" (20%) ISSUED Boulder Current TO 1100 PM SAT 0.3" (60%) to 0.5" (40%) to 1" (20%) ISSUED Broomfield Current TO 1100 PM SAT 0.3" (60%) to 0.5" (40%) to 1" (20%) ISSUED Denver Current TO 1100 PM SAT 0.3" (60%) to 0.5" (40%) to 1" (20%) ISSUED Douglas Current TO 1100 PM SAT 0.3" (60%) to 0.5" (40%) to 1" (20%) ISSUED Jefferson Current TO 1100 PM SAT 0.3" (60%) to 0.5" (40%) to 1" (20%) ISSUED Foothills above 6500ft       Boulder Current TO 1100 PM SAT 0.3" (60%) to 0.5" (40%) to 1" (20%) ISSUED Douglas Current TO 1100 PM SAT 0.3" (60%) to 0.5" (40%) to 1" (20%) ISSUED Jefferson Current TO 1100 PM SAT 0.3" (60%) to 0.5" (40%) to 1" (20%) 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]