Flash Flood Prediction Program

Time: 831 AM Wed September 29, 2021 Forecaster: Justin Brooks ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- COOLER TODAY WITH A GOOD CHANCE FOR AFTERNOON/EVENING RAIN SHOWERS/ISOLATED THUNDERSTORMS - Cooler today behind a cold front that moved through the region yesterday. Today's high temperatures will only reach the mid 60's to around 70 on the plains with low 60's along the foothills. A good chance this afternoon for widespread rain showers with isolated thunderstorms possible as well if temperatures are able to warm enough this afternoon. - Best chance for rain showers activity today will be from 2-8pm with lingering rain showers possible late into the evening with off and on light rain showers possible through the overnight and into early Thursday morning. Best chance for rainfall today will be along the foothills where anchored rain showers will likely produce the most rainfall. - Overnight temperatures will drop into the 40's along the plains with mid to upper 30's along the foothills resulting in a chance for snow this evening and overnight for areas above 9,000ft. STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers will produce TR-0.2" in 10-30 minutes. A moderate rain showers or isolated thunderstorm could produce 0.2-0.4" in 10-30 minutes. WORST CASE SCENARIO: A strong thunderstorm, an anchored rain shower or training or rain showers will have the potential to produce 0.8" of rainfall in under 60 minutes. A LOOK AHEAD: Another cold front will move through late this evening effectively dropping tomorrow high temperatures into the upper 50's to low 60's across the plains. A chance remains tomorrow afternoon and evening for scattered rain showers. A slight warm up Friday as highs reach the mid 60's to around 70 degrees with another good chance for widespread rains showers/isolated thunderstorms. similar conditions both Saturday and Sunday with chances for rain showers/isolated thunderstorms in the afternoon and early evening. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 200 PM TO 900 PM Trace (60%) to 0.2" (30%) to 0.4" (10%) NONE Arapahoe 200 PM TO 900 PM Trace (60%) to 0.2" (30%) to 0.4" (10%) NONE Boulder 200 PM TO 900 PM Trace (60%) to 0.2" (30%) to 0.4" (10%) NONE Broomfield 200 PM TO 900 PM Trace (60%) to 0.2" (30%) to 0.4" (10%) NONE Denver 200 PM TO 900 PM Trace (60%) to 0.2" (30%) to 0.4" (10%) NONE Douglas 200 PM TO 900 PM Trace (60%) to 0.2" (30%) to 0.4" (10%) NONE Jefferson 200 PM TO 900 PM Trace (60%) to 0.2" (30%) to 0.4" (10%) NONE Foothills above 6500ft       Boulder 200 PM TO 900 PM Trace (60%) to 0.2" (40%) to 0.4" (20%) NONE Douglas 200 PM TO 900 PM Trace (60%) to 0.2" (40%) to 0.4" (20%) NONE Jefferson 200 PM TO 900 PM Trace (60%) to 0.2" (40%) to 0.4" (20%) 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]