Time: 1054 AM Thu July 28, 2022 Forecaster: Justin Brooks ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 2'S HAVE BEEN ISSUED FOR PORTIONS OF THE DISTRICT WITH MESSAGE 1'S ISSUED FOR THE REMAINDER - Message 2's (NWS Flash Flood/Flood Watch) have been issued for Boulder, Broomfield and Jefferson Counties valid 11:00 AM until 10:00 PM. Message 1's have been issued for the remainder of the District to coincide with Message 2's effective 11:00 AM until 10:00 PM this evening. - Cooler and cloudy today after another overnight heavy rainfall threat. An excess of available moisture at the surface and upper-levels combined with a disturbance that will move through this afternoon has brought an increased threat for widespread heavy rainfall. Rain showers and thunderstorms will fist develop along the higher terrain between now till noon with storms likely moving into the District between noon and 1pm. Prime time for moderate to strong thunderstorms will be until 9 or 10pm before skies gradually clear into the overnight with minimal rainfall expected past midnight tonight. - Thunderstorms will be efficient rainfall producers very capable of producing heavy downpours that may lead to excessive runoff and possibly flash flooding. Storms will be relatively slow moving from W to E between 5-10mph, with a chance some storms may anchor in place leading to an increase chance for isolated long lasting moderate to heavy rainfall. STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers/thunderstorms will produce 0.3-1.0" in 10-30 minutes. Moderate to strong thunderstorms will have the potential to produce rainfall rates of 1.0-2.0 in 10-30 minutes. WORST CASE SCENARIO: A strong anchored thunderstorm or training of moderate to strong thunderstorms may result in rainfall rates up to 3.0" in 45-75 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Douglas County 1 1100 AM TO 1000 PM 1100 AM TO 1000 PM Broomfield County 2 1100 AM TO 1000 PM 1100 AM TO 1000 PM Jefferson County 2 1100 AM TO 1000 PM 1100 AM TO 1000 PM Boulder County 2 1100 AM TO 1000 PM 1100 AM TO 1000 PM Lakewood 2 1100 AM TO 1000 PM 1100 AM TO 1000 PM Wheat Ridge 2 1100 AM TO 1000 PM 1100 AM TO 1000 PM Arvada 2 1100 AM TO 1000 PM 1100 AM TO 1000 PM the City of Aurora 1 1100 AM TO 1000 PM 1100 AM TO 1000 PM Arapahoe County 1 1100 AM TO 1000 PM 1100 AM TO 1000 PM DIA 1 1100 AM TO 1000 PM 1100 AM TO 1000 PM Denver County 1 1100 AM TO 1000 PM 1100 AM TO 1000 PM Adams County 1 1100 AM TO 1000 PM 1100 AM TO 1000 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 1100 AM TO 1159 PM 0.3" (90%) to 1.0" (45%) to 2.0" (20%) ISSUED Arapahoe 1100 AM TO 1159 PM 0.3" (90%) to 1.0" (45%) to 2.0" (20%) ISSUED Boulder 1100 AM TO 1159 PM 0.3" (90%) to 1.0" (45%) to 2.0" (20%) ISSUED Broomfield 1100 AM TO 1159 PM 0.3" (90%) to 1.0" (45%) to 2.0" (20%) ISSUED Denver 1100 AM TO 1159 PM 0.3" (90%) to 1.0" (45%) to 2.0" (20%) ISSUED Douglas 1100 AM TO 1159 PM 0.3" (90%) to 1.0" (45%) to 2.0" (20%) ISSUED Jefferson 1100 AM TO 1159 PM 0.3" (90%) to 1.0" (45%) to 2.0" (20%) ISSUED Foothills above 6500ft       Boulder 1100 AM TO 1159 PM 0.3" (95%) to 1.0" (50%) to 2.0" (25%) ISSUED Douglas 1100 AM TO 1159 PM 0.3" (95%) to 1.0" (50%) to 2.0" (25%) ISSUED Jefferson 1100 AM TO 1159 PM 0.3" (95%) to 1.0" (50%) to 2.0" (25%) 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]