Flash Flood Prediction Program

Time: 859 AM Thu September 29, 2022 Forecaster: Brad Simmons ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- CONTINUED WARM WITH CLOUD COVER ON THE INCREASE AND ISOLATED AFTERNOON SHOWERS/THUNDERSTORMS - Temperatures will continue to run well above seasonal averages but below record levels today. Highs this afternoon will reach the low to mid 80's over the plains with 70's in the Front Range foothills. Normal high for Denver today is 74 degrees with a record high of 92 degrees. - SW flow aloft will increase mid and upper level moisture and cloud cover will be on the increase as the day progresses with isolated rain showers and weak thunderstorms this afternoon and evening. Rain showers and weak thunderstorms will develop over the higher terrain by around noon or shortly after. Upper level steering winds from SW to NE at around 15-20mph will then push the storms onto the plains by 1-2pm. By 6 or 7pm shower activity will be on the decrease with conditions drying out this evening. - Rain showers and weak thunderstorms that develop this afternoon will be high-based producing minimal rainfall and gusty winds. Many areas likely end up on the drier side or experience just a few sprinkles. Best chances for measurable precipitation today will be in and near the foothills. Conditions will be dry for the overnight period with lows into Friday morning in the 40's foothills and lower 50's plains. STORM RAINFALL POTENTIAL AND DURATION: Rain showers and high-based weak thunderstorms will produce a trace to 0.2" of rain in 10-30 minutes. A LOOK AHEAD: An approaching trough of low pressure will increase shower and thunderstorm coverage on Friday. Scattered rain showers and weak to moderate thunderstorms will fill in during the afternoon and continue possible well into the evening as a cold front moves through. Much cooler Saturday with additional rain showers expected and possibly a rumble of thunder. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 100 PM TO 700 PM Trace (60%) to 0.1" (30%) to 0.2" (10%) NONE Arapahoe 100 PM TO 700 PM Trace (60%) to 0.1" (30%) to 0.2" (10%) NONE Boulder 100 PM TO 700 PM Trace (75%) to 0.1" (50%) to 0.2" (15%) NONE Broomfield 100 PM TO 700 PM Trace (60%) to 0.1" (30%) to 0.2" (10%) NONE Denver 100 PM TO 700 PM Trace (60%) to 0.1" (30%) to 0.2" (10%) NONE Douglas 100 PM TO 700 PM Trace (75%) to 0.1" (50%) to 0.2" (15%) NONE Jefferson 100 PM TO 700 PM Trace (75%) to 0.1" (50%) to 0.2" (15%) NONE Foothills above 6500ft       Boulder 1200 PM TO 700 PM Trace (80%) to 0.1" (50%) to 0.2" (20%) NONE Douglas 1200 PM TO 700 PM Trace (80%) to 0.1" (50%) to 0.2" (20%) NONE Jefferson 1200 PM TO 700 PM Trace (80%) to 0.1" (50%) to 0.2" (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]