Flash Flood Prediction Program

Time: 455 PM Sun August 14, 2022 Forecaster: Brad Simmons ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1'S CONTINUE VALID - Message 1's issued for the entire District will continue valid until 10:00 PM but may be rescinded early if conditions warrant. - Thunderstorms west of the District diminished upon approach but sent a rain cooled outflow boundary eastward which triggered new thunderstorms over Weld County and southward over parts of Douglas and Elbert Counties. The majority of this thunderstorm activity has remained outside the District boundaries. Storms to the N have initiated a new gust front which is pushing southward and may trigger new storms over the next few hours. - Thunderstorms if they develop will be slow moving or may anchor briefly resulting in a continued threat for heavy rain should a strong thunderstorm be observed. With cooler temperatures now in place the chance for strong thunderstorms is lower than earlier this afternoon and as temperatures continue to cool into the evening the chances for strong thunderstorms will continue to decrease. STORM RAINFALL POTENTIAL AND DURATION: Weak to moderate thunderstorms will have the potential to produce 0.1-0.4" in 10-30 minutes. Strong thunderstorms will have the potential to produce rainfall rates of 0.4-1.2" in 10-30 minutes. WORST CASE SCENARIO: A slower moving or briefly anchored strong thunderstorm may produce rainfall amounts of up to 2.0" in 45-75 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Boulder County 1 Current TO 1000 PM 200 PM TO 900 PM Jefferson County 1 Current TO 1000 PM 200 PM TO 900 PM Broomfield County 1 Current TO 1000 PM 200 PM TO 900 PM Douglas County 1 Current TO 1000 PM 200 PM TO 900 PM Adams County 1 Current TO 1000 PM 200 PM TO 900 PM Denver County 1 Current TO 1000 PM 200 PM TO 900 PM DIA 1 Current TO 1000 PM 200 PM TO 900 PM Arapahoe County 1 Current TO 1000 PM 200 PM TO 900 PM the City of Aurora 1 Current TO 1000 PM 200 PM TO 900 PM Arvada 1 Current TO 1000 PM 200 PM TO 900 PM Wheat Ridge 1 Current TO 1000 PM 200 PM TO 900 PM Lakewood 1 Current TO 1000 PM 200 PM TO 900 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 1000 PM SUN 0.1" (50%) to 0.4" (25%) to 1.0" (10%) ISSUED Arapahoe Current TO 1000 PM SUN 0.1" (75%) to 0.4" (40%) to 1.0" (15%) ISSUED Boulder Current TO 1000 PM SUN 0.1" (60%) to 0.4" (30%) to 1.0" (15%) ISSUED Broomfield Current TO 1000 PM SUN 0.1" (50%) to 0.4" (25%) to 1.0" (10%) ISSUED Denver Current TO 1000 PM SUN 0.1" (60%) to 0.4" (30%) to 1.0" (15%) ISSUED Douglas Current TO 1000 PM SUN 0.1" (80%) to 0.4" (40%) to 1.0" (20%) ISSUED Jefferson Current TO 1000 PM SUN 0.1" (60%) to 0.4" (30%) to 1.0" (15%) ISSUED Foothills above 6500ft       Boulder Current TO 1000 PM SUN 0.1" (80%) to 0.4" (40%) to 1.0" (15%) ISSUED Douglas Current TO 1000 PM SUN 0.1" (80%) to 0.4" (40%) to 1.0" (15%) ISSUED Jefferson Current TO 1000 PM SUN 0.1" (80%) to 0.4" (40%) to 1.0" (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]