Time: 629 PM Tue June 7, 2022 Forecaster: Brad Simmons ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- THUNDERSTORM CHANCES DECREASING/ADDITIONAL SHOWERS AND POSSIBLY A RUMBLE OF THUNDER OVERNIGHT - Elevated moisture levels over the District today with surface dew points in the upper 40's to lower 50's in tandem with daytime heating produced a boom or bust type setup for thunderstorms and the outcome has been "bust" over the District as the strong thunderstorm activity initiated to the S and E. - Now that temperatures are beginning to back off from afternoon highs the threat for strong thunderstorms is decreasing but not completely eliminated. Outflow from storms to the E and SE could push back westward and trigger thunderstorm development towards the I-25 corridor. However, the risk for thunderstorms will decrease each hour through sunset. - A cold front will also move through late this evening and will produce low clouds and a few widely scattered light rain showers overnight with possibly an isolated rumble of thunder. Cloud cover may persist into Wednesday morning but the shower activity is expected to have ended ahead of daybreak. Shower activity overnight will likely favor areas in and near the foothills and over the Palmer Divide with light amounts. STORM RAINFALL POTENTIAL AND DURATION: Rain showers and weak thunderstorms will produce a trace to 0.2" in 10-30 minutes. WORST CASE SCENARIO: Outflow boundary from thunderstorms to the E/SE pushes back into the District triggering strong thunderstorm development with the potential to produce 0.3-0.9" of heavy rain in 10-30 minutes. A LOOK AHEAD: Drier air is expected to work its way into the District on Wednesday lowering the chances for thunderstorms with isolated coverage anticipated, favoring the foothills and Palmer Divide. Highs Wednesday will range from the upper 70's to lower 80's over the plains. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 400 AM WED Trace (40%) to 0.1" (20%) to 0.2" (10%) NONE Arapahoe Current TO 400 AM WED Trace (40%) to 0.1" (20%) to 0.2" (10%) NONE Boulder Current TO 400 AM WED Trace (50%) to 0.1" (25%) to 0.2" (10%) NONE Broomfield Current TO 400 AM WED Trace (40%) to 0.1" (20%) to 0.2" (10%) NONE Denver Current TO 400 AM WED Trace (40%) to 0.1" (20%) to 0.2" (10%) NONE Douglas Current TO 400 AM WED Trace (50%) to 0.1" (25%) to 0.2" (10%) NONE Jefferson Current TO 400 AM WED Trace (50%) to 0.1" (25%) to 0.2" (10%) NONE Foothills above 6500ft       Boulder Current TO 400 AM WED Trace (60%) to 0.1" (30%) to 0.2" (10%) NONE Douglas Current TO 400 AM WED Trace (60%) to 0.1" (30%) to 0.2" (10%) NONE Jefferson Current TO 400 AM WED Trace (60%) to 0.1" (30%) to 0.2" (10%) 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]