Time: 203 PM Sat October 1, 2022 Forecaster: Brad Simmons ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1'S ISSUED FOR THE ENTIRE DISTRICT - Message 1's have been issued for the entire District and will be valid until 8:00 PM this evening. - An upper level disturbance will move overhead this afternoon and evening producing rain showers and thunderstorms. Thunderstorms will have the potential to produce brief heavy rainfall, hail and gusty winds. The first line or two of storms will likely be the strongest of the day with subsequent rounds into the evening likely favoring a general rain versus thunderstorms. - Prime time for thunderstorm activity will be from roughly 3pm through 7 or 8pm. After 7 or 8pm rain shower activity will continue into the evening but rainfall rates are anticipated to decrease becoming light to briefly moderate. STORM RAINFALL POTENTIAL AND DURATION: Rain showers and weak thunderstorms will produce 0.1-0.4" of rain in 30-60 minutes. Moderate to strong thunderstorms will have the potential to produce rainfall rates of 0.4-1.0" in 10-30 minutes. WORST CASE SCENARIO: Training of thunderstorm cells or a slower moving thunderstorm may result in up to 1.5" of rain in 60 minutes or less. COUNTY MESSAGE VALID TIMES PRIME TIME Boulder County 1 200 PM TO 800 PM 300 PM TO 700 PM Jefferson County 1 200 PM TO 800 PM 300 PM TO 700 PM Broomfield County 1 200 PM TO 800 PM 300 PM TO 700 PM Douglas County 1 200 PM TO 800 PM 300 PM TO 700 PM Adams County 1 200 PM TO 800 PM 300 PM TO 700 PM Denver County 1 200 PM TO 800 PM 300 PM TO 700 PM DIA 1 200 PM TO 800 PM 300 PM TO 700 PM Arapahoe County 1 200 PM TO 800 PM 300 PM TO 700 PM the City of Aurora 1 200 PM TO 800 PM 300 PM TO 700 PM Arvada 1 200 PM TO 800 PM 300 PM TO 700 PM Wheat Ridge 1 200 PM TO 800 PM 300 PM TO 700 PM Lakewood 1 200 PM TO 800 PM 300 PM TO 700 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 800 PM SAT 0.1" (80%) to 0.4" (40%) to 1.0" (20%) ISSUED Arapahoe Current TO 800 PM SAT 0.1" (80%) to 0.4" (40%) to 1.0" (20%) ISSUED Boulder Current TO 800 PM SAT 0.1" (80%) to 0.4" (40%) to 1.0" (15%) ISSUED Broomfield Current TO 800 PM SAT 0.1" (80%) to 0.4" (40%) to 1.0" (15%) ISSUED Denver Current TO 800 PM SAT 0.1" (80%) to 0.4" (40%) to 1.0" (20%) ISSUED Douglas Current TO 800 PM SAT 0.1" (80%) to 0.4" (40%) to 1.0" (20%) ISSUED Jefferson Current TO 800 PM SAT 0.1" (80%) to 0.4" (40%) to 1.0" (15%) ISSUED Foothills above 6500ft       Boulder Current TO 800 PM SAT 0.1" (90%) to 0.4" (40%) to 1.0" (10%) ISSUED Douglas Current TO 800 PM SAT 0.1" (90%) to 0.4" (40%) to 1.0" (10%) ISSUED Jefferson Current TO 800 PM SAT 0.1" (90%) to 0.4" (40%) to 1.0" (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]