Time: 823 AM Wed September 14, 2022 Forecaster: Justin Brooks ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- COOLER TODAY WITH A GOOD CHANCE FOR SHOWERS/THUNDERSTORMS THIS AFTERNOON AND EVENING - High-pressure begins to break down today, combined with left over moisture from a tropical disturbance from the Pacific will bring a good chance for rain showers/thunderstorms this afternoon and evening. High temperatures today will reach a more seasonable upper 70's to low 80's this afternoon. - A few very weak isolated showers currently along the higher terrain, will continue to increase as the morning progresses with thunderstorm development likely along the Continental Divide by midday. These storm will move SW to NE between 10-15mph through the District, with the best chance for storms between 2-8pm with shower activity tapering off between 8-10pm. These storm motions should help limit point rainfall amounts. However with excess available moisture from the tropical disturbance, a LOW chance for Message issuance today as some storms have the potential for brief heavy rainfall, with the largest threat being a quick 0.5" in 10-30 minutes if stronger storms are able to develop. - As showers taper off into the evening, skies will gradually clear through the overnight with cool and mild conditions expected into Thursday. Overnight lows will drop into the mid to upper 50's on the plains with upper 40's to low 50's along the foothills. STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers/isolated thunderstorms will produce a trace to 0.2" in 10-30minutes. A moderate to strong thunderstorms can produce 0.2-0.5" in 10-30 minutes. WORST CASE SCENARIO: A slower moving thunderstorm or training of thunderstorm cells has the potential to produce up to 1.5" in 45-75 minutes. A LOOK AHEAD: This active weather pattern remains in place tomorrow with another good chance for afternoon and evening rain showers/thunderstorms, with a slight chance for overnight showers into Friday. Temperatures will be slightly cooler tomorrow with highs nearly 80 degrees in the afternoon. Warmer Friday as high temperatures reach the low 80's with a slight chance for another round of afternoon rain showers/isolated thunderstorms. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 200 PM TO 800 PM Trace (75%) to 0.2" (50%) to 0.5" (25%) LOW Arapahoe 200 PM TO 800 PM Trace (75%) to 0.2" (50%) to 0.5" (25%) LOW Boulder 200 PM TO 800 PM Trace (75%) to 0.2" (50%) to 0.5" (25%) LOW Broomfield 200 PM TO 800 PM Trace (75%) to 0.2" (50%) to 0.5" (25%) LOW Denver 200 PM TO 800 PM Trace (75%) to 0.2" (50%) to 0.5" (25%) LOW Douglas 200 PM TO 800 PM Trace (75%) to 0.2" (50%) to 0.5" (25%) LOW Jefferson 200 PM TO 800 PM Trace (75%) to 0.2" (50%) to 0.5" (25%) LOW Foothills above 6500ft       Boulder 200 PM TO 800 PM Trace (80%) to 0.2" (60%) to 0.5" (30%) LOW Douglas 200 PM TO 800 PM Trace (80%) to 0.2" (60%) to 0.5" (30%) LOW Jefferson 200 PM TO 800 PM Trace (80%) to 0.2" (60%) to 0.5" (30%) 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]