Flash Flood Prediction Program

Time: 652 PM Tue July 19, 2022 Forecaster: Brad Simmons ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1'S WILL BE ALLOWED TO EXPIRE AT 8PM - Message 1's issued for Adams, Arapahoe, Denver, Douglas and Jefferson Counties will be allowed to expire at 8:00pm. - Briefly strong thunderstorms impacted portions of the District earlier this afternoon producing isolated areas of moderate to briefly heavy rainfall. Shower and thunderstorm activity has diminished currently with possibly a few light rain showers re-developing into the early overnight period. - A thunderstorm complex over western CO, should it survive will result in rain showers and possibly a weak thunderstorm developing after sunset into the early morning hours on Wednesday. Heavy rainfall is not expected from overnight shower activity should it develop. STORM RAINFALL POTENTIAL AND DURATION: Rain showers and weak thunderstorms will produce a trace to 0.3" in 10-30 minutes. WORST CASE SCENARIO: A moderate to briefly strong thunderstorm is able to develop overnight with the potential to produce rainfall rates of 0.3-0.9" in 10-30 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Jefferson County 1 Current TO 800 PM Current TO 700 PM Douglas County 1 Current TO 800 PM Current TO 700 PM Denver County 1 Current TO 800 PM Current TO 700 PM Arapahoe County 1 Current TO 800 PM Current TO 700 PM the City of Aurora 1 Current TO 800 PM Current TO 700 PM Arvada 1 Current TO 800 PM Current TO 700 PM Wheat Ridge 1 Current TO 800 PM Current TO 700 PM Lakewood 1 Current TO 800 PM Current TO 700 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 400 AM WED Trace (40%) to 0.1" (20%) to 0.3" (10%) NONE Arapahoe Current TO 400 AM WED Trace (60%) to 0.1" (30%) to 0.3" (15%) NONE Boulder Current TO 400 AM WED Trace (40%) to 0.1" (20%) to 0.3" (10%) NONE Broomfield Current TO 400 AM WED Trace (40%) to 0.1" (20%) to 0.3" (10%) NONE Denver Current TO 400 AM WED Trace (50%) to 0.1" (25%) to 0.3" (10%) NONE Douglas Current TO 400 AM WED Trace (60%) to 0.1" (30%) to 0.3" (15%) NONE Jefferson Current TO 400 AM WED Trace (50%) to 0.1" (25%) to 0.3" (10%) NONE Foothills above 6500ft       Boulder Current TO 400 AM WED Trace (60%) to 0.1" (30%) to 0.3" (15%) NONE Douglas Current TO 400 AM WED Trace (60%) to 0.1" (30%) to 0.3" (15%) NONE Jefferson Current TO 400 AM WED Trace (60%) to 0.1" (30%) to 0.3" (15%) NONE MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS. MHFD Flood Prediction Center: 303-458-0789    F2P2 Website [http://udfcd.org/Flash+Flood+Prediction+Program]