Time: 601 PM Sat July 17, 2021 Forecaster: Brad Simmons ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1'S ISSUED FOR PORTIONS OF THE DISTRICT - Message 1's have been issued for Adams, Arapahoe, Denver, Douglas and Jefferson Counties until 9:30pm this evening. - Thunderstorms are developing over central and eastern portions of the District currently and may be energized by a gust front approaching form the north. Currently storms are weak to moderate but may be intensified as the gust front from the N moves through over the coming hours. - Thunderstorms will be nearly stationary or slow moving to the S at around 10mph. Strong thunderstorms will be capable of producing heavy rainfall that may lead to excessive runoff and possibly flash flooding. STORM RAINFALL POTENTIAL AND DURATION: Weak to moderate thunderstorms will produce 0.1-0.3" in 10-30 minutes. Strong thunderstorms will have the potential to produce 0.3-0.8" in 10-30 minutes. WORST CASE SCENARIO: A stationary strong thunderstorm may result in up to 1.5" of rain in 45-60 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Jefferson County 1 Current TO 930 PM Current TO 830 PM Lakewood 1 Current TO 930 PM Current TO 830 PM Wheat Ridge 1 Current TO 930 PM Current TO 830 PM Arvada 1 Current TO 930 PM Current TO 830 PM the City of Aurora 1 Current TO 930 PM Current TO 830 PM Arapahoe County 1 Current TO 930 PM Current TO 830 PM DIA 1 Current TO 930 PM Current TO 830 PM Denver County 1 Current TO 930 PM Current TO 830 PM Adams County 1 Current TO 930 PM Current TO 830 PM Douglas County 1 Current TO 930 PM Current TO 830 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 930 PM SAT 0.1" (85%) to 0.3" (60%) to 0.8" (20%) ISSUED Arapahoe Current TO 930 PM SAT 0.1" (85%) to 0.3" (60%) to 0.8" (20%) ISSUED Boulder Current TO 930 PM SAT 0.1" (65%) to 0.3" (30%) to 0.8" (10%) LOW Broomfield Current TO 930 PM SAT 0.1" (65%) to 0.3" (30%) to 0.8" (10%) LOW Denver Current TO 930 PM SAT 0.1" (85%) to 0.3" (60%) to 0.8" (20%) ISSUED Douglas Current TO 930 PM SAT 0.1" (85%) to 0.3" (60%) to 0.8" (20%) ISSUED Jefferson Current TO 930 PM SAT 0.1" (85%) to 0.3" (60%) to 0.8" (20%) ISSUED Foothills above 6500ft       Boulder Current TO 930 PM SAT 0.1" (65%) to 0.3" (30%) to 0.8" (10%) LOW Douglas Current TO 930 PM SAT 0.1" (85%) to 0.3" (60%) to 0.8" (20%) ISSUED Jefferson Current TO 930 PM SAT 0.1" (85%) to 0.3" (60%) to 0.8" (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]