Flash Flood Prediction Program

Time: 1222 PM Fri July 2, 2021 Forecaster: Justin Brooks ------------------------- 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 9pm this evening. Storm have begun to develop along the foothills at this time and will continue to build before moving onto the plains this afternoon. - Current dew points are at an elevated mid to upper 50's with low 60's just east of the District. This suggests the chance for heavy rainfall, even out of weak to moderate storms. Storm motions today will also be fairly slow to nearly stationary at times from west to east. This will increase the chance for isolated heavy rain with the potential for flash flooding. Roadways/smaller creeks and streams will be most prone to excessive runoff/flooding today. - Best chance for storms in the District will be between 1-9pm.A few lingering showers and thunderstorms could be possible after 9pm, mainly for areas out on the eastern plains. Drier upper-level air begins to move in behind todays disturbance which will gradually clear skies through the evening. STORM RAINFALL POTENTIAL AND DURATION: Weak thunderstorms will produce 0.2-0.5" of rain in 10-30 minutes. Moderate to strong thunderstorms will have the potential to produce heavy rainfall rates of 0.5-1.5" in 10-30 minutes WORST CASE SCENARIO: Training of thunderstorm cells or a large slow moving strong thunderstorm may result in very heavy rainfall of up to 3.0" in 60-90 minutes. Should rain continue for longer than 90 minutes in duration higher amounts are possible. COUNTY MESSAGE VALID TIMES PRIME TIME Lakewood 1 Current TO 900 PM Current TO 800 PM Wheat Ridge 1 Current TO 900 PM Current TO 800 PM Arvada 1 Current TO 900 PM Current TO 800 PM the City of Aurora 1 Current TO 900 PM Current TO 800 PM Arapahoe County 1 Current TO 900 PM Current TO 800 PM DIA 1 Current TO 900 PM Current TO 800 PM Denver County 1 Current TO 900 PM Current TO 800 PM Adams County 1 Current TO 900 PM Current TO 800 PM Douglas County 1 Current TO 900 PM Current TO 800 PM Broomfield County 1 Current TO 900 PM Current TO 800 PM Jefferson County 1 Current TO 900 PM Current TO 800 PM Boulder County 1 Current TO 900 PM Current TO 800 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 900 PM FRI 0.2" (75%) to 0.5" (50%) to 1.5" (25%) ISSUED Arapahoe Current TO 900 PM FRI 0.2" (75%) to 0.5" (50%) to 1.5" (25%) ISSUED Boulder Current TO 900 PM FRI 0.2" (75%) to 0.5" (50%) to 1.5" (25%) ISSUED Broomfield Current TO 900 PM FRI 0.2" (75%) to 0.5" (50%) to 1.5" (25%) ISSUED Denver Current TO 900 PM FRI 0.2" (75%) to 0.5" (50%) to 1.5" (25%) ISSUED Douglas Current TO 900 PM FRI 0.2" (75%) to 0.5" (50%) to 1.5" (25%) ISSUED Jefferson Current TO 900 PM FRI 0.2" (75%) to 0.5" (50%) to 1.5" (25%) ISSUED Foothills above 6500ft       Boulder Current TO 900 PM FRI 0.2" (75%) to 0.5" (50%) to 1.5" (20%) ISSUED Douglas Current TO 900 PM FRI 0.2" (75%) to 0.5" (50%) to 1.5" (20%) ISSUED Jefferson Current TO 900 PM FRI 0.2" (75%) to 0.5" (50%) to 1.5" (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]