Flash Flood Prediction Program

Time: 904 AM Fri September 9, 2022 Forecaster: Brad Simmons ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- COOL AIR HAS ARRIVED! RAIN SHOWERS AND MIST/DRIZZLE TO FILL IN LATER AFTERNOON AND CONTINUE OVERNIGHT - After record breaking heat over the past few days, cooler air has arrived behind a cold front that moved through overnight. Temperatures today will only warm into the 50's in the Front Range foothills with readings in the 60's to around 70 degrees over the plains. - Conditions will trend dry through much of the day but there will be a slight chance for a rain shower or very isolated weak thunderstorm this afternoon after 2 or 3pm. If a thunderstorm were to develop it would favor the foothills S of I-70 and over the crest of the Palmer Divide over Douglas County. Clouds will increase as the afternoon progresses with light rain showers and areas of mist/drizzle developing towards sunset. Light showers/mist/drizzle will fill in this evening and become widespread overnight as cooler air continues to filter into NE CO. Areas of fog may also develop overnight and persist into Saturday morning. - The majority of the precipitation will be light with prime time for widespread shower activity from roughly 6 or 7pm this evening until midday Saturday. Total moisture will likely range from 0.10-0.30" into Saturday morning with isolated higher and lower amounts possible. Temperatures overnight will dip into the 40's over the plains STORM RAINFALL POTENTIAL AND DURATION: Rain showers and areas of mist/drizzle will produce rainfall rates of a trace to 0.2" in 60 minutes. WORST CASE SCENARIO: An isolated thunderstorm is able to develop with the potential to produce rainfall rates of 0.1-0.3" in 10-30 minutes. A LOOK AHEAD: Cloudy and cool with light rain showers and areas of mist/drizzle through the first half of the day Saturday. Conditions will slowly dry out Saturday afternoon with dry conditions developing ahead of midnight. Temperatures Saturday will be even cooler than today in the 50's to around 60 over the plains with more cloud cover. Drier and warmer for Sunday. LOCATION PRIME TIME 60-Minute Rainfall and % Probability Message Potential Plains       Arapahoe 500 PM TO 1000 AM SAT Trace (90%) to 0.1" (60%) to 0.2" (30%) NONE Douglas 500 PM TO 1000 AM SAT Trace (90%) to 0.1" (60%) to 0.2" (30%) NONE Adams 400 PM TO 1000 AM SAT Trace (95%) to 0.1" (60%) to 0.2" (30%) NONE Boulder 400 PM TO 1000 AM SAT Trace (95%) to 0.1" (60%) to 0.2" (30%) NONE Broomfield 400 PM TO 1000 AM SAT Trace (95%) to 0.1" (60%) to 0.2" (30%) NONE Denver 400 PM TO 1000 AM SAT Trace (95%) to 0.1" (60%) to 0.2" (30%) NONE Jefferson 400 PM TO 1000 AM SAT Trace (95%) to 0.1" (60%) to 0.2" (30%) NONE Foothills above 6500ft       Boulder 200 PM TO 1000 AM SAT Trace (90%) to 0.1" (60%) to 0.2" (30%) NONE Douglas 200 PM TO 1000 AM SAT Trace (90%) to 0.1" (60%) to 0.2" (30%) NONE Jefferson 200 PM TO 1000 AM SAT Trace (90%) to 0.1" (60%) to 0.2" (30%) 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]