Time: 556 PM Tue July 12, 2022 Forecaster: Brad Simmons ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1'S ISSUED FOR THE EASTERN AREAS OF THE DISTRICT - Message 1's have been issued for Adams, Arapahoe and Denver Counties and will be valid until 9:00 PM. - Colliding outflow boundaries has resulted in thunderstorm activity east of I-25 over portions of Adams, Arapahoe and Denver Counties. These storms are currently strengthening and may produce heavy rainfall as well as large hail and gusty winds. - Thunderstorms may remain nearly stationary before being carried away by upper level winds. Otherwise storms will generally move from NW to SE at around 20mph. Best chances for strong to severe thunderstorms will be over the next couple hours. STORM RAINFALL POTENTIAL AND DURATION: Moderate to strong thunderstorms will have the potential to produce rainfall rates of 0.4-1.0" in 10-30 minutes. WORST CASE SCENARIO: A slower moving strong thunderstorm or briefly anchored thunderstorm may result in up to 1.6" of heavy rainfall in 45-60 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME the City of Aurora 1 Current TO 900 PM 615 PM TO 800 PM Arapahoe County 1 Current TO 900 PM 615 PM TO 800 PM Denver County 1 Current TO 900 PM 615 PM TO 800 PM Adams County 1 Current TO 900 PM 615 PM TO 800 PM DIA 1 Current TO 900 PM 615 PM TO 800 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 900 PM TUE 0.1" (100%) to 0.4" (75%) to 1.0" (40%) ISSUED Arapahoe Current TO 900 PM TUE 0.1" (90%) to 0.4" (60%) to 1.0" (30%) ISSUED Boulder Current TO 900 PM TUE 0.1" (50%) to 0.4" (25%) to 1.0" (10%) LOW Broomfield Current TO 900 PM TUE 0.1" (50%) to 0.4" (25%) to 1.0" (10%) LOW Denver Current TO 900 PM TUE 0.1" (90%) to 0.4" (60%) to 1.0" (30%) ISSUED Douglas Current TO 900 PM TUE 0.1" (75%) to 0.4" (50%) to 1.0" (15%) MOD Jefferson Current TO 900 PM TUE 0.1" (50%) to 0.4" (25%) to 1.0" (10%) LOW Foothills above 6500ft       Boulder Current TO 900 PM TUE 0.1" (40%) to 0.4" (20%) to 1.0" (5%) LOW Douglas Current TO 900 PM TUE 0.1" (40%) to 0.4" (20%) to 1.0" (5%) LOW Jefferson Current TO 900 PM TUE 0.1" (40%) to 0.4" (20%) to 1.0" (5%) LOW MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS. MHFD Flood Prediction Center: 303-458-0789    F2P2 Website [http://udfcd.org/Flash+Flood+Prediction+Program]