Time: 937 AM Thu June 27, 2024 Forecaster: Justin Brooks ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- Cool and cloudy this morning with a good chance of afternoon and evening showers and thunderstorms. A few sprinkles to light rain for portions of the District this morning will clear out as the morning progresses. Temperatures today will reach the upper 80s to around 90 degrees this afternoon. There will be a couple of rounds of storms today, the first this afternoon, likely between 1-4pm and another late round sometime between 7-10pm. A few lingering showers will be possible overnight, although the largest threat for moderate to heavy rainfall will be during the initial round and possibly into the later evening. A slight chance storms become severe today, mainly for areas east of the District, with gusty winds up to 60mph and hail up to 1.0” in diameter. Initial storm development will occur by midday along the higher elevations and move into the District during the early afternoon. Storm motions will be from west to east between 10-20mph which should help limit point rainfall amounts. However, stronger storms will produce outflow boundaries, likely creating erratic storm movement leading to a better chance of isolated moderate to heavy rainfall. The largest threat today will most likely be a quick 0.50-0.75” in 10-30 minutes, rather than any long-lasting rainfall. Storms will lose intensity into the evening hours with more widespread showers possible between 7-10pm, although an embedded thunderstorm or two cannot be completely ruled out. A few lingering showers overnight as temperatures decrease into the low to mid 60s on the plains. STORM RAINFALL POTENTIAL AND DURATION: Typical showers and isolated thunderstorms will produce a 0.05-0.25” total in 10-30 minutes. A moderate to strong shower/thunderstorm will produce 0.25-0.75” 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 1.50” total in 30-60 minutes. A LOOK AHEAD: Very little overall change to the pattern tomorrow will lead to similar conditions as there will be another chance for afternoon and evening showers and thunderstorms. Another slight chance storms will become severe, with the potential for moderate to heavy rainfall continuing. Saturday will cool off into the 80s with a continued chance for showers in the afternoon and evening. A decrease in moisture will result in mostly high-based shower activity with a few isolated thunderstorms possible in the afternoon and early evening. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 200 PM TO 1100 PM 0.05" (60%) to 0.25" (30%) to 0.75" (15%) MOD Arapahoe 200 PM TO 1100 PM 0.05" (60%) to 0.25" (30%) to 0.75" (15%) MOD Boulder 200 PM TO 1100 PM 0.05" (60%) to 0.25" (30%) to 0.75" (15%) MOD Broomfield 200 PM TO 1100 PM 0.05" (60%) to 0.25" (30%) to 0.75" (15%) MOD Denver 200 PM TO 1100 PM 0.05" (60%) to 0.25" (30%) to 0.75" (15%) MOD Douglas 200 PM TO 1100 PM 0.05" (60%) to 0.25" (30%) to 0.75" (15%) MOD Jefferson 200 PM TO 1100 PM 0.05" (60%) to 0.25" (30%) to 0.75" (15%) MOD Foothills above 6500ft       Boulder 100 PM TO 1000 PM 0.05" (70%) to 0.25" (35%) to 0.75" (20%) MOD Douglas 100 PM TO 1000 PM 0.05" (70%) to 0.25" (35%) to 0.75" (20%) MOD Jefferson 100 PM TO 1000 PM 0.05" (70%) to 0.25" (35%) to 0.75" (20%) 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]