Flash Flood Prediction Program

Time: 1051 AM Wed July 6, 2022 Forecaster: Brad Simmons ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- STRONG THUNDERSTORMS WILL BE VERY CAPABLE OF PRODUCING HEAVY RAINFALL - Message 1's have been issued for the entire District and will be valid until 9:00 PM this evening. - Moderate to strong thunderstorms that develop this afternoon will be very capable of producing heavy rainfall that may lead to excessive runoff roadways and possibly flash flooding. - Prime time for thunderstorm activity is from 12:00-8:00 PM. More numerous showers and thunderstorms will favor the foothills and Palmer Divide but the stronger storms are expected to favor the plains. Slow storm motions from SW to NE and potential training of thunderstorm cells will be the main culprits for extended periods of heavy rainfall. STORM RAINFALL POTENTIAL AND DURATION: Rain showers will produce a trace to 0.2" in 10-30 minutes. Weak thunderstorms will produce rainfall rates of 0.2-0.6" in 10-30 minutes. Moderate to strong thunderstorms will have the potential to produce 0.6-1.8" in 10-30 minutes. WORST CASE SCENARIO: A large thunderstorm complex or a slow moving large thunderstorm may result in up to 3.0" of rain in 45-75 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Boulder County 1 1100 AM TO 900 PM 1200 PM TO 800 PM Jefferson County 1 1100 AM TO 900 PM 1200 PM TO 800 PM Broomfield County 1 1100 AM TO 900 PM 1200 PM TO 800 PM Douglas County 1 1100 AM TO 900 PM 1200 PM TO 800 PM Adams County 1 1100 AM TO 900 PM 100 PM TO 800 PM Denver County 1 1100 AM TO 900 PM 100 PM TO 800 PM DIA 1 1100 AM TO 900 PM 100 PM TO 800 PM Arapahoe County 1 1100 AM TO 900 PM 100 PM TO 800 PM the City of Aurora 1 1100 AM TO 900 PM 100 PM TO 800 PM Arvada 1 1100 AM TO 900 PM 1200 PM TO 800 PM Wheat Ridge 1 1100 AM TO 900 PM 1200 PM TO 800 PM Lakewood 1 1100 AM TO 900 PM 1200 PM TO 800 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 1200 PM TO 900 PM 0.2" (80%) to 0.8" (40%) to 1.6" (20%) ISSUED Arapahoe 1200 PM TO 900 PM 0.2" (80%) to 0.8" (40%) to 1.6" (20%) ISSUED Boulder 1200 PM TO 900 PM 0.2" (80%) to 0.8" (40%) to 1.6" (20%) ISSUED Broomfield 1200 PM TO 900 PM 0.2" (80%) to 0.8" (40%) to 1.6" (20%) ISSUED Denver 1200 PM TO 900 PM 0.2" (80%) to 0.8" (40%) to 1.6" (20%) ISSUED Douglas 1200 PM TO 900 PM 0.2" (80%) to 0.8" (40%) to 1.6" (20%) ISSUED Jefferson 1200 PM TO 900 PM 0.2" (80%) to 0.8" (40%) to 1.6" (20%) ISSUED Foothills above 6500ft       Boulder Current TO 900 PM WED 0.2" (90%) to 0.8" (50%) to 1.6" (15%) ISSUED Douglas Current TO 900 PM WED 0.2" (90%) to 0.8" (50%) to 1.6" (15%) ISSUED Jefferson Current TO 900 PM WED 0.2" (90%) to 0.8" (50%) to 1.6" (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]