Time: 910 AM Thu August 24, 2023 Forecaster: Laura Smith ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- ISOLATED AFTERNOON TO EVENING SHOWERS AND THUNDERSTORMS Today will be partly sunny with afternoon temperatures in the low to mid 90s, dew points in the upper 40s to around 50°F, followed by a chance for afternoon to evening showers and thunderstorms. Storm activity will be broadly limited to complex terrain during the afternoon. Showers and thunderstorms may develop across portions of the District later this evening. Storm motions will be from south to north, moving around 20-25 mph. Quick storm motions will help limit point rainfall amounts. Storm activity is expected to move out of the District late tonight. STORM RAINFALL POTENTIAL AND DURATION: Typical showers will be weak, producing rainfall of TR-0.25” total in 10-30 minutes. Stronger storms have the potential to produce heavy rainfall of 0.25” to 0.50” total in 10-30 minutes. WORST CASE SCENARIO: Training or strong thunderstorms have the potential to produce 0.50” to 1.00” total in 30-60 minutes. A LOOK AHEAD: As upper-level conditions continue to shift east tonight, the remnants of a tropical system will expand across the state. This wave of moisture will support cooler temperatures and rainy conditions through the end of the week and possibly into the weekend. Storm activity continues tomorrow across the Plains with high confidence for heavy rain. Afternoon temperatures will reach the upper 70s to low 80s. There is still some uncertainty about details and timing through the weekend, which will depend on the track of this system. We will continue to monitor conditions as they develop over the coming days. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 200 PM TO 1000 PM Trace (80%) to 0.25" (50%) to 0.5" (20%) LOW Arapahoe 200 PM TO 1000 PM Trace (80%) to 0.25" (50%) to 0.5" (20%) LOW Boulder 200 PM TO 1100 PM Trace (80%) to 0.25" (50%) to 0.5" (20%) LOW Broomfield 200 PM TO 1000 PM Trace (80%) to 0.25" (50%) to 0.5" (20%) LOW Denver 200 PM TO 1000 PM Trace (80%) to 0.25" (50%) to 0.5" (20%) LOW Douglas 200 PM TO 1000 PM Trace (80%) to 0.25" (50%) to 0.5" (20%) LOW Jefferson 200 PM TO 1000 PM Trace (80%) to 0.25" (50%) to 0.5" (20%) LOW Foothills above 6500ft       Boulder 200 PM TO 1100 PM Trace (80%) to 0.25" (50%) to 0.5" (20%) LOW Douglas 200 PM TO 1000 PM Trace (80%) to 0.25" (50%) to 0.5" (20%) LOW Jefferson 200 PM TO 1000 PM Trace (80%) to 0.25" (50%) to 0.5" (20%) 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]