Flash Flood Prediction Program

Time: 844 AM Tue September 27, 2022 Forecaster: Brad Simmons ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- ISOLATED, HIGH-BASED AFTERNOON SHOWERS/THUNDERSTORMS FAVORING THE HIGHER TERRAIN - An increase in mid and upper level moisture will lead to a chance for showers and weak thunderstorms over the District today. Temperatures will continue to run above seasonal averages with readings in the upper 70's to lower 80's over the plains with 60's and 70's in the Front Range foothills. Mostly sunny skies early will become partly to mostly cloudy as convective clouds develop this afternoon. - Most of the shower and weak thunderstorm activity today will remain over the mountains, foothills, and higher terrain of the Palmer Divide with lesser chances over the plains between 2-8pm. The storms that develop today will be high-based as surface moisture is lacking resulting in minimal rainfall and gusty winds. Many areas along the I-25 corridor will likely end up dry or experience just a few gusty sprinkles. - After 8pm conditions are expected to dry out with overnight lows dropping into the 40's foothills and upper 40's to lower 50's plains into Wednesday morning. STORM RAINFALL POTENTIAL AND DURATION: Rain showers and weak thunderstorms will produce rainfall amounts of a trace to 0.2" in 10-30 minutes. A LOOK AHEAD: Shower and thunderstorm activity is expected to retreat back into the higher mountains on Wednesday leaving the I-25 corridor on the dry side. Temperatures will remain either side of 80 degrees for highs over the plains with readings about 10 degrees cooler in the foothills. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 200 PM TO 800 PM Trace (30%) to 0.1" (15%) to 0.2" (5%) NONE Arapahoe 200 PM TO 800 PM Trace (40%) to 0.1" (20%) to 0.2" (5%) NONE Boulder 200 PM TO 800 PM Trace (50%) to 0.1" (30%) to 0.2" (10%) NONE Broomfield 200 PM TO 800 PM Trace (50%) to 0.1" (30%) to 0.2" (10%) NONE Denver 200 PM TO 800 PM Trace (40%) to 0.1" (20%) to 0.2" (5%) NONE Douglas 200 PM TO 800 PM Trace (50%) to 0.1" (30%) to 0.2" (10%) NONE Jefferson 200 PM TO 800 PM Trace (50%) to 0.1" (30%) to 0.2" (10%) NONE Foothills above 6500ft       Boulder 100 PM TO 800 PM Trace (75%) to 0.1" (50%) to 0.2" (25%) NONE Douglas 100 PM TO 800 PM Trace (75%) to 0.1" (50%) to 0.2" (25%) NONE Jefferson 100 PM TO 800 PM Trace (75%) to 0.1" (50%) to 0.2" (25%) 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]