Flash Flood Prediction Program

Time: 832 AM Wed June 23, 2021 Forecaster: Justin Brooks ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- HOT AND HAZY WITH A VERY SLIGHT CHANCE FOR ISOLATED AFTERNOON/EVE HIGH-BASED RAIN SHOWERS/THUNDERSTORMS - Another hot and hazy day as afternoon high temperatures reach the low to mid 90's on the plains with mid to upper 80's along the foothills. Wildfire smoke out west will continue to move into the region bringing hazy conditions throughout the day today. - A very slight chance for isolated afternoon and evening high-based rain/thunderstorms with little to no precipitation expected as most will evaporate before reaching the ground. The largest threat today will be gusty winds and possibly a few lightning strikes. Storms will initiate over the higher terrain afternoon noon with the best chance for storms over the District between 2-8pm. Rain chances taper off after 8pm with partly cloudy skies through the overnight. - Overnight lows will drop into the mid to upper 60's for the plains with upper 50's to low 60's along the foothills. STORM RAINFALL POTENTIAL AND DURATION: Typical high-based rain showers/isolated thunderstorms will produce a trace in 10-30 minutes. A stronger high-based rain shower/isolated thunderstorm could produce a trace-0.1" in 10-30 minutes. WORST CASE SCENARIO: An anchored foothills rain shower/isolated thunderstorm has the potential to produce 0.1-0.3" in 60 to 90 minutes. A LOOK AHEAD: Similar conditions Thursday as high temperatures reach the mid to upper 80's in the afternoon with another slight chance for high-based rain showers/isolated thunderstorms in the afternoon and evening. A change in the pattern Friday as a cold front moves through the region bringing a better chance for rain showers/thunderstorms in the afternoon and evening with a slight chance for those storms to become severe. Cooler temperatures will also accompany this cold front with highs in the mid to upper 70's for the plains with low 70's along the foothills. Cooler high temperatures and rain chances continue Saturday with low 70's in the afternoon along with a continued chance for rain/thunderstorms, along with a slight chance for severe weather if we are able to get enough daytime heating. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 200 PM TO 800 PM Trace (10%) to 0.1" (5%) to 0.3" (0%) NONE Arapahoe 200 PM TO 800 PM Trace (10%) to 0.1" (5%) to 0.3" (0%) NONE Boulder 200 PM TO 800 PM Trace (10%) to 0.1" (5%) to 0.3" (0%) NONE Broomfield 200 PM TO 800 PM Trace (10%) to 0.1" (5%) to 0.3" (0%) NONE Denver 200 PM TO 800 PM Trace (10%) to 0.1" (5%) to 0.3" (0%) NONE Douglas 200 PM TO 800 PM Trace (10%) to 0.1" (5%) to 0.3" (0%) NONE Jefferson 200 PM TO 800 PM Trace (10%) to 0.1" (5%) to 0.3" (0%) NONE Foothills above 6500ft       Boulder 200 PM TO 700 PM Trace (15%) to 0.1" (10%) to 0.3" (5%) NONE Douglas 200 PM TO 700 PM Trace (15%) to 0.1" (10%) to 0.3" (5%) NONE Jefferson 200 PM TO 700 PM Trace (15%) to 0.1" (10%) to 0.3" (5%) 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]