Time: 1003 AM Tue July 16, 2024 Forecaster: Laura Smith ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- Scattered to Widespread Showers and Thunderstorms this afternoon and evening. Temperatures will begin to normalize today as the heatwave slowly breaks down. Anomalously high atmospheric moisture will advect into the High Plains today by an upper-level disturbance from the Pacific Northwest. Afternoon temperatures will reach the upper 80s to low 90s, dewpoints in the upper 40s to low 50s, and precipitable water (PWAT) values around 0.95”. Coupled with an approaching cold front, these conditions will support scattered to widespread thunderstorms across the District capable of producing more meaningful rainfall (when compared to the last few days). Convection initiation will begin around noon across the foothills, with storms moving east onto the plains between 15-25 mph. Rainfall will favor the Foothills and Palmer Divide, with slightly lower rainfall amounts possible across the Plains. Thunderstorm activity is expected to dissipate by the late evening, with skies gradually clearing overnight. STORM RAINFALL POTENTIAL AND DURATION: Thunderstorms today have the potential to produce 0.25”-0.75” in 10-30 minutes. WORST CASE SCENARIO: A slow-moving, strong thunderstorm may be capable of producing up to 1.25” or more in 30 minutes or less. A LOOK AHEAD: Subtropical moisture continues increasing Wednesday to around 150% of normal, while afternoon high temperatures cool another 4-6 degrees following the cold front overnight. Guidance suggests scattered to widespread storms Wednesday may be capable of producing meaningful rainfall across portions of the District tomorrow afternoon and evening. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 100 PM TO 1100 PM 0.1" (75%) to 0.3" (50%) to 0.6" (25%) LOW Arapahoe 100 PM TO 1100 PM 0.1" (75%) to 0.3" (50%) to 0.6" (25%) LOW Boulder 100 PM TO 1100 PM 0.1" (75%) to 0.3" (50%) to 0.6" (25%) LOW Broomfield 100 PM TO 1100 PM 0.1" (75%) to 0.3" (50%) to 0.6" (25%) LOW Denver 100 PM TO 1100 PM 0.1" (75%) to 0.3" (50%) to 0.6" (25%) LOW Douglas 100 PM TO 1100 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Jefferson 100 PM TO 1100 PM 0.1" (75%) to 0.3" (50%) to 0.6" (25%) LOW Foothills above 6500ft       Boulder 1200 PM TO 1000 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Douglas 1200 PM TO 1000 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Jefferson 1200 PM TO 1000 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) 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]