Flash Flood Prediction Program

Time: 917 AM Sun July 10, 2022 Forecaster: Brad Simmons ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- HOT... ISOLATED AFTERNOON THUNDERSTORMS WILL PROVIDE RELIEF FROM THE HEAT FOR SOME - Temperatures will continue to be hot over the District today with temperatures climbing into the mid 90's to around 100 over the plains. Isolated areas may reach or exceed 100 degrees! Record high for today is 102 and will likely not be reached as there will be more clouds this afternoon. - There is a little more moisture to work with in the mid and upper levels of the atmosphere today and will result in isolated afternoon thunderstorms. The majority of the storms that develop today will be high-based producing gusty winds and minimal rainfall. Surface wind convergence may be able to energize a storm or two over the plains with a moderate to briefly strong thunderstorm possible but chances are quite low and will be the worst case scenario for today resulting in a LOW Message potential. - Thunderstorms will develop between 1-2pm over the higher terrain with best chances on the plains from 2-9pm. Typical storms will move from SW to NE at around 20mph. Stronger storms may move more erratically or remain nearly stationary on surface wind convergence boundaries. Shower and storm activity will be of the hit-or-miss variety and not everyone will experience a storm but the areas that do will receive a little relief from the heat this afternoon. STORM RAINFALL POTENTIAL AND DURATION: Rain showers and weak thunderstorms will produce a trace to 0.1" of rain. Moderate thunderstorms will have the potential to produce rainfall rates of 0.1-0.3" in 10-30 minutes. WORST CASE SCENARIO: Strong thunderstorms will have the potential to produce rainfall rates of 0.3-0.8" in 10-30 minutes and up to 1.0" in 45-60 minutes. A LOOK AHEAD: A cold front will move through ahead of daybreak tomorrow and result in much cooler temperatures with highs only in the 80's over the plains with 70's in the Front Range foothills. Moisture will increase behind the front but the cooler temperatures over the plains may help to retard thunderstorm development over the plains with scattered coverage over the foothills and Palmer Divide. If strong thunderstorms are able to develop Monday afternoon heavy rainfall will likely accompany the storms. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 200 PM TO 900 PM Trace (75%) to 0.1" (50%) to 0.3" (20%) LOW Arapahoe 200 PM TO 900 PM Trace (75%) to 0.1" (50%) to 0.3" (20%) LOW Boulder 200 PM TO 900 PM Trace (80%) to 0.1" (50%) to 0.3" (20%) LOW Broomfield 200 PM TO 900 PM Trace (75%) to 0.1" (50%) to 0.3" (20%) LOW Denver 200 PM TO 900 PM Trace (75%) to 0.1" (50%) to 0.3" (20%) LOW Douglas 200 PM TO 900 PM Trace (80%) to 0.1" (50%) to 0.3" (20%) LOW Jefferson 200 PM TO 900 PM Trace (80%) to 0.1" (50%) to 0.3" (20%) LOW Foothills above 6500ft       Boulder 100 PM TO 900 PM Trace (90%) to 0.1" (60%) to 0.3" (20%) NONE Douglas 100 PM TO 900 PM Trace (90%) to 0.1" (60%) to 0.3" (20%) NONE Jefferson 100 PM TO 900 PM Trace (90%) to 0.1" (60%) to 0.3" (20%) 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]