Flash Flood Prediction Program

Time: 940 AM Sat September 9, 2023 Forecaster: Laura Smith ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- HOT SUMMERTIME CONDITIONS WITH ISOLATED LATE AFTERNOON/EVENING THUNDERSTORMS This morning will be sunny with afternoon highs reaching the mid to upper 80s, dew points in the mid to upper 30s, under mostly clear skies. Later this afternoon, an upper-level disturbance and its associated cold front will sweep across the area followed by a slight chance for late afternoon to early evening isolated showers and thunderstorms. STORM RAINFALL POTENTIAL AND DURATION: Typical isolated thunderstorms will produce light rainfall of up to 0.25” in 10-30 minutes. WORST CASE SCENARIO: A strong thunderstorm, although unlikely, has the potential to produce rainfall up to 0.50” in 45-60 minutes. A LOOK AHEAD: The approaching system will support an unsettled weather pattern and much cooler temperatures through the middle of next week. Tomorrow will be partly cloudy and stormy with high temperatures in the low to mid 70s. Thunderstorms may persist from early afternoon through late evening. There is still some uncertainty about details and timing early next week, which will depend on the track of this system. We will continue to monitor this storm as it develops over the coming days. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 400 PM TO 900 PM Trace (50%) to 0.25" (30%) to 0.5" (10%) LOW Arapahoe 400 PM TO 900 PM Trace (50%) to 0.25" (30%) to 0.5" (10%) LOW Boulder 400 PM TO 900 PM Trace (50%) to 0.25" (30%) to 0.5" (10%) LOW Broomfield 400 PM TO 900 PM Trace (50%) to 0.25" (30%) to 0.5" (10%) LOW Denver 400 PM TO 900 PM Trace (50%) to 0.25" (30%) to 0.5" (10%) LOW Douglas 400 PM TO 900 PM Trace (50%) to 0.25" (30%) to 0.5" (10%) LOW Jefferson 400 PM TO 900 PM Trace (50%) to 0.25" (30%) to 0.5" (10%) LOW Foothills above 6500ft       Boulder 400 PM TO 900 PM Trace (50%) to 0.25" (30%) to 0.5" (10%) LOW Douglas 400 PM TO 900 PM Trace (50%) to 0.25" (30%) to 0.5" (10%) LOW Jefferson 400 PM TO 900 PM Trace (50%) to 0.25" (30%) to 0.5" (10%) LOW MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS. MHFD Flood Prediction Center: 303-458-0789    F2P2 Website [http://udfcd.org/Flash+Flood+Prediction+Program]