Time: 924 AM Sun June 9, 2024 Forecaster: Justin Brooks ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- Slightly cooler than seasonable temperatures today with another chance for afternoon and evening showers and isolated thunderstorms. High-pressure starts to build today as temperatures struggle to reach 80 degrees this afternoon. Dew points currently in the 50s and will likely hold during the day today. This will enhance the threat of brief heavy rainfall during the afternoon and early evening before skies gradually clear through the overnight tonight. The best chance for moderate to heavy shower/thunderstorm activity within the District will be between 2-8pm with a few lingering showers possible through midnight. The best chance for heavy rainfall will be during the initial round of storms, with storm intensities decreasing after sunset. Storm motions will be minimal, with most storms behaving in a pulse up manner with little to no actual movement, leading to an increased chance for isolated heavy rainfall within the District. A low chance remains for severe weather today, mainly for gusty winds of 60+ mph and hail up to 1.0” in diameter, favoring areas east of I-25 at this time. Skies will gradually clear overnight and into daybreak Monday as temperatures drop into the mid to upper 50s on the plains with upper 40s to around 50 degrees along the foothills. STORM RAINFALL POTENTIAL AND DURATION: Typical showers and isolated thunderstorms will produce a 0.05-0.30” total in 10-30 minutes. A moderate to strong/severe shower/thunderstorm will produce 0.30-0.60” total in 10-30 minutes. WORST CASE SCENARIO: A strong, stationary thunderstorm, or training of thunderstorm cells will have the potential to produce up to 1.20” total in under 60 minutes. A LOOK AHEAD: Minimal overall change Monday as high temperatures remain in the low to mid 80s. A continued chance for afternoon and early evening showers/thunderstorms, with a slight chance some of those storms produce brief heavy rainfall, likely keeping a LOW chance for Messages. Conditions start to dry out Tuesday with just a typical chance for springtime afternoon showers/isolated thunderstorms. Wednesday is expected to be even drier with minimal, if any, chance for precipitation at this time across the District. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 1200 PM TO 1000 PM 0.1" (80%) to 0.3" (60%) to 0.6" (30%) MOD Arapahoe 1200 PM TO 1000 PM 0.1" (80%) to 0.3" (60%) to 0.6" (30%) MOD Boulder 1200 PM TO 1000 PM 0.1" (75%) to 0.3" (50%) to 0.6" (25%) MOD Broomfield 1200 PM TO 1000 PM 0.1" (75%) to 0.3" (50%) to 0.6" (25%) MOD Denver 1200 PM TO 1000 PM 0.1" (80%) to 0.3" (60%) to 0.6" (30%) MOD Douglas 1200 PM TO 1000 PM 0.1" (75%) to 0.3" (50%) to 0.6" (25%) MOD Jefferson 1200 PM TO 1000 PM 0.1" (75%) to 0.3" (50%) to 0.6" (25%) MOD Foothills above 6500ft       Boulder 1200 PM TO 1000 PM 0.1" (60%) to 0.3" (40%) to 0.6" (20%) LOW Douglas 1200 PM TO 1000 PM 0.1" (60%) to 0.3" (40%) to 0.6" (20%) LOW Jefferson 1200 PM TO 1000 PM 0.1" (60%) to 0.3" (40%) to 0.6" (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]