Time: 936 AM Tue August 16, 2022 Forecaster: Brad Simmons ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1'S ISSUED FOR THE ENTIRE DISTRICT/MESSAGE 3'S VALID UNTIL 11:00 AM FOR BOULDER/BROOMFIELD COUNTIES - Message 1's have been issued for the entire District as an area of heavy non-thunderstorm rain has developed over NW portions of the District impacting portions of Boulder, Broomfield, Adams and Jefferson Counties. These showers have already produced 1-3" of rain or more and has resulted in Message 3's (NWS Flash Flood Warning) for portions of Boulder and Broomfield Counties with minor flooding ongoing over parts of Adams and Jefferson Counties. The Message 3's are valid until 11:00 AM. - These non-thunderstorm heavy rain showers are expected to slowly sag south as the day progresses. Best chances for rain showers will be into the early afternoon. Moisture is expected to decrease this afternoon and the best chances for rain will eventually push south of the District by late afternoon. - Thunderstorm chances will hinge upon daytime heating and if we see some sunshine this afternoon a few isolated thunderstorms may develop. If thunderstorms are able to develop they will be vary capable of producing heavy rain. Due to all of the rain yesterday and overnight the ground is saturated in many areas and it may not take as much rain today to produce excessive runoff. STORM RAINFALL POTENTIAL AND DURATION: Non-thunderstorm rain showers will have the potential to produce rainfall rates of 0.5-1.5" in 10-30 minutes and 2.0-3.0" in 60-90 minutes. WORST CASE SCENARIO: A thunderstorm is able to develop this afternoon with heavy rainfall rates of 0.8-2.2" in 10-30 minutes and up to 3.5" in 45-60 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Boulder County 1 Current TO 600 PM Current TO 500 PM Jefferson County 1 Current TO 600 PM Current TO 500 PM Broomfield County 1 Current TO 600 PM Current TO 500 PM Douglas County 1 Current TO 600 PM Current TO 500 PM Adams County 1 Current TO 600 PM Current TO 500 PM Denver County 1 Current TO 600 PM Current TO 500 PM DIA 1 Current TO 600 PM Current TO 500 PM Arapahoe County 1 Current TO 600 PM Current TO 500 PM the City of Aurora 1 Current TO 600 PM Current TO 500 PM Arvada 1 Current TO 600 PM Current TO 500 PM Wheat Ridge 1 Current TO 600 PM Current TO 500 PM Lakewood 1 Current TO 600 PM Current TO 500 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 600 PM TUE 0.3" (100%) to 0.8" (75%) to 1.5" (40%) ISSUED Arapahoe Current TO 600 PM TUE 0.3" (100%) to 0.8" (60%) to 1.5" (30%) ISSUED Boulder Current TO 600 PM TUE 0.3" (100%) to 0.8" (75%) to 1.5" (40%) ISSUED Broomfield Current TO 600 PM TUE 0.3" (100%) to 0.8" (80%) to 1.5" (60%) ISSUED Denver Current TO 600 PM TUE 0.3" (100%) to 0.8" (65%) to 1.5" (35%) ISSUED Douglas Current TO 600 PM TUE 0.3" (100%) to 0.8" (60%) to 1.5" (30%) ISSUED Jefferson Current TO 600 PM TUE 0.3" (100%) to 0.8" (70%) to 1.5" (35%) ISSUED Foothills above 6500ft       Boulder Current TO 600 PM TUE 0.3" (95%) to 0.8" (50%) to 1.5" (25%) ISSUED Douglas Current TO 600 PM TUE 0.3" (95%) to 0.8" (50%) to 1.5" (25%) ISSUED Jefferson Current TO 600 PM TUE 0.3" (95%) to 0.8" (50%) to 1.5" (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]