Flash Flood Prediction Program

Time: 927 AM Sun May 30, 2021 Forecaster: Brad Simmons ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1'S ISSUED FOR THE ENTIRE DISTRICT - Message 1's have been issued for the entire District and will be valid until 11pm this evening. Rain showers are on the increase over the District at this time with thunderstorms possible as the day progresses. - Rain showers will become widespread with embedded thunderstorms capable of producing heavy rainfall that may lead to excessive runoff and possibly flash flooding. Most thunderstorms that develop today are expected to be weak with brief heavy rainfall but a stronger storm will be capable of extended periods of heavy rainfall due to slow storm motions. - Rainfall rates from non-thunderstorm moderate to heavy rain showers will generally be in the 0.1-0.4"/hr rate but may reach up to 1.0"/hr rate under heavier showers. Creeks and streams will likely be running high later today and tonight and it may not take much rain to produce excessive runoff if the ground becomes saturated. STORM RAINFALL POTENTIAL AND DURATION: Weak thunderstorms will have the potential to produce 0.2-0.6" in 10-30 minutes. Moderate to strong thunderstorms will have the potential to produce 0.4-1.2" in 10-30 minutes. WORST CASE SCENARIO: A strong thunderstorm becomes stationary with up to 2.4" of rain possible in 45-75 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Wheat Ridge 1 Current TO 1100 PM Current TO 1000 PM Arvada 1 Current TO 1100 PM Current TO 1000 PM the City of Aurora 1 Current TO 1100 PM Current TO 1000 PM Arapahoe County 1 Current TO 1100 PM Current TO 1000 PM DIA 1 Current TO 1100 PM Current TO 1000 PM Denver County 1 Current TO 1100 PM Current TO 1000 PM Adams County 1 Current TO 1100 PM Current TO 1000 PM Douglas County 1 Current TO 1100 PM Current TO 1000 PM Broomfield County 1 Current TO 1100 PM Current TO 1000 PM Jefferson County 1 Current TO 1100 PM Current TO 1000 PM Boulder County 1 Current TO 1100 PM Current TO 1000 PM Lakewood 1 Current TO 1100 PM Current TO 1000 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 1100 PM SUN 0.1" (100%) to 0.4" (75%) to 1.0" (25%) HIGH Arapahoe Current TO 1100 PM SUN 0.1" (100%) to 0.4" (75%) to 1.0" (25%) HIGH Boulder Current TO 1100 PM SUN 0.1" (100%) to 0.4" (75%) to 1.0" (25%) HIGH Broomfield Current TO 1100 PM SUN 0.1" (100%) to 0.4" (75%) to 1.0" (25%) HIGH Denver Current TO 1100 PM SUN 0.1" (100%) to 0.4" (75%) to 1.0" (25%) HIGH Douglas Current TO 1100 PM SUN 0.1" (100%) to 0.4" (80%) to 1.0" (30%) HIGH Jefferson Current TO 1100 PM SUN 0.1" (100%) to 0.4" (75%) to 1.0" (25%) HIGH Foothills above 6500ft       Boulder Current TO 1100 PM SUN 0.1" (100%) to 0.4" (75%) to 1.0" (25%) HIGH Douglas Current TO 1100 PM SUN 0.1" (100%) to 0.4" (80%) to 1.0" (30%) HIGH Jefferson Current TO 1100 PM SUN 0.1" (100%) to 0.4" (75%) to 1.0" (25%) HIGH MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS. MHFD Flood Prediction Center: 303-458-0789    F2P2 Website [http://udfcd.org/Flash+Flood+Prediction+Program]