Time: 922 AM Sun August 14, 2022 Forecaster: Brad Simmons ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- WIDELY SCATTERED AFTERNOON/EVENING SHOWERS/THUNDERSTORMS WITH TEMPERATURES CONTINUING TO RUN ABOVE SEASONAL AVERAGES - Ridge of high pressure will begin to slowly break down today but temperatures will continue to run above seasonal averages. Highs this afternoon will peak in the lower 90's over the plains with 70's and 80's in the Front Range foothills. Mid and upper level moisture will begin to increase and should lead to better storm coverage than previous days with isolated to widely scattered afternoon thunderstorms plains and scattered storms foothills. - Thunderstorms will develop over the mountains and foothills W of the District between noon-2pm. There is more of a westerly component to the upper level winds today and storms should begin to be pushed over the plains between 2-3pm. There will be a modest chance for showers and thunderstorms until 9 or 10pm then conditions will dry out for the later evening and overnight period. - With a bit more moisture to work with today the typical storms that develop will produce light to briefly moderate rain. Strong thunderstorms are not anticipated but if a strong thunderstorm develops it will be slow moving and capable of producing small areas of heavy rainfall. Best chances for a stronger storm today will be in or near the foothills. Overall, most storms will move from W to E at 10-15mph with stronger storms potentially moving more slowly or anchoring briefly. STORM RAINFALL POTENTIAL AND DURATION: Rain showers and weak thunderstorms will produce a trace to 0.2" of rain. Moderate to briefly strong thunderstorms will have the potential to produce rainfall rates of 0.2-0.6" in 10-30 minutes. WORST CASE SCENARIO: A slower moving or briefly anchored strong thunderstorm may produce rainfall rates of 0.4-1.2" in 10-30 minutes and up to 1.8" in 45-60 minutes. A LOOK AHEAD: An upper level disturbance will move overhead on Monday and result in an active weather day with scattered to numerous afternoon and evening rain showers/thunderstorms. Stronger storms will be very capable of producing heavy rainfall that may lead to excessive runoff and possibly flash flooding. The NWS in Boulder may issue a Flood Watch/Flash Flood Watch later today for Monday due to the threat for heavy rain. Temperatures will be much cooler in the low to mid 80's for highs. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 300 PM TO 1000 PM Trace (75%) to 0.3" (35%) to 0.6" (15%) LOW Arapahoe 300 PM TO 1000 PM Trace (75%) to 0.3" (35%) to 0.6" (15%) LOW Broomfield 300 PM TO 1000 PM Trace (75%) to 0.3" (35%) to 0.6" (15%) LOW Denver 300 PM TO 1000 PM Trace (75%) to 0.3" (35%) to 0.6" (15%) LOW Boulder 200 PM TO 1000 PM Trace (80%) to 0.3" (40%) to 0.6" (20%) LOW Douglas 200 PM TO 1000 PM Trace (80%) to 0.3" (40%) to 0.6" (20%) LOW Jefferson 200 PM TO 1000 PM Trace (80%) to 0.3" (40%) to 0.6" (20%) LOW Foothills above 6500ft       Boulder 100 PM TO 1000 PM Trace (95%) to 0.3" (60%) to 0.6" (30%) MOD Douglas 100 PM TO 1000 PM Trace (95%) to 0.3" (60%) to 0.6" (30%) MOD Jefferson 100 PM TO 1000 PM Trace (95%) to 0.3" (60%) to 0.6" (30%) MOD MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS. MHFD Flood Prediction Center: 303-458-0789    F2P2 Website [http://udfcd.org/Flash+Flood+Prediction+Program]