Time: 216 PM Mon June 28, 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 and will be valid until 8pm this evening. - Weak to briefly moderate thunderstorms over the foothills of Boulder County earlier today has produced a gust front that is pushing SE through the District and may be a trigger for stronger thunderstorms to develop later this afternoon. Since this gust front/outflow boundary has already passed Boulder and Broomfield Counties they are not included in the Message 1's at this time but may be added later this afternoon if conditions warrant. - Moderate to strong thunderstorms will be capable of producing heavy rainfall that may lead to excessive runoff and possibly flash flooding. Best chances for thunderstorms will be over the next 4-5hours. STORM RAINFALL POTENTIAL AND DURATION: Moderate to strong thunderstorms will have the potential to produce 0.3-0.8" in 10-30 minutes. WORST CASE SCENARIO: A large or slower moving thunderstorm may result in up to 1.5" of rain in 45-60 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Lakewood 1 Current TO 800 PM 245 PM TO 600 PM Arvada 1 Current TO 800 PM 245 PM TO 600 PM Wheat Ridge 1 Current TO 800 PM 245 PM TO 600 PM the City of Aurora 1 Current TO 800 PM 245 PM TO 600 PM DIA 1 Current TO 800 PM 245 PM TO 600 PM Arapahoe County 1 Current TO 800 PM 245 PM TO 600 PM Denver County 1 Current TO 800 PM 245 PM TO 600 PM Adams County 1 Current TO 800 PM 245 PM TO 600 PM Douglas County 1 Current TO 800 PM 245 PM TO 600 PM Jefferson County 1 Current TO 800 PM 245 PM TO 600 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 800 PM MON 0.1" (80%) to 0.4" (60%) to 0.8" (30%) ISSUED Arapahoe Current TO 800 PM MON 0.1" (80%) to 0.4" (60%) to 0.8" (30%) ISSUED Boulder Current TO 800 PM MON 0.1" (60%) to 0.4" (30%) to 0.8" (15%) MOD Broomfield Current TO 800 PM MON 0.1" (50%) to 0.4" (25%) to 0.8" (10%) MOD Denver Current TO 800 PM MON 0.1" (80%) to 0.4" (60%) to 0.8" (30%) ISSUED Douglas Current TO 800 PM MON 0.1" (80%) to 0.4" (60%) to 0.8" (30%) ISSUED Jefferson Current TO 800 PM MON 0.1" (80%) to 0.4" (60%) to 0.8" (30%) ISSUED Foothills above 6500ft       Boulder Current TO 800 PM MON 0.1" (60%) to 0.4" (30%) to 0.8" (15%) MOD Douglas Current TO 800 PM MON 0.1" (80%) to 0.4" (60%) to 0.8" (30%) ISSUED Jefferson Current TO 800 PM MON 0.1" (80%) to 0.4" (60%) to 0.8" (30%) 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]