Time: 929 AM Fri June 28, 2024 Forecaster: Justin Brooks ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- Another hot day today with a chance for afternoon and evening showers/isolated thunderstorms A minimal change to the overall pattern will bring similar conditions as yesterday across the District. Once again, a few sprinkles to light rain for areas north of the District this morning have cleared out at this time. Temperatures will reach the low 90s this afternoon with partly cloudy skies. There will be a chance for a couple of rounds of storms today, the first this afternoon, likely between 1-5pm and another late round sometime between 7pm-midnight. A few lingering showers will be possible during the 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/northeast 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 generally be between 10-15mph which should help limit point rainfall amounts. However, stronger storms could produce outflow boundaries, likely resulting in some erratic storm movement leading to a better chance of isolated moderate to heavy rainfall. The largest threat today will most likely be a quick 0.50-0.60” in 10-30 minutes, rather than any long-lasting rainfall. Storms will lose intensity into the evening hours with more widespread showers possible between 7pm-midnight, although a few embedded thunderstorms cannot be completely ruled out. A few lingering showers overnight as temperatures decrease into the low 60s on the plains with mid to upper 50s 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 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 30-60 minutes. A LOOK AHEAD: Tomorrow will cool off into the 80s behind a cold front, with a continued chance for showers in the afternoon and evening. An overall decrease in moisture will result in mostly high-based shower activity with a few isolated thunderstorms possible in the afternoon and early evening. Conditions start to dry out Sunday with temperatures jumping back into the 90s. A slight chance for a few high-based showers/isolated thunderstorms, favoring the higher terrain at this time, rather than any meaningful rainfall within the District. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 200 PM TO 1159 PM 0.05" (60%) to 0.3" (30%) to 0.6" (15%) LOW Arapahoe 200 PM TO 1159 PM 0.05" (60%) to 0.3" (30%) to 0.6" (15%) LOW Boulder 200 PM TO 1159 PM 0.05" (60%) to 0.3" (30%) to 0.6" (15%) LOW Broomfield 200 PM TO 1159 PM 0.05" (60%) to 0.3" (30%) to 0.6" (15%) LOW Denver 200 PM TO 1159 PM 0.05" (60%) to 0.3" (30%) to 0.6" (15%) LOW Douglas 200 PM TO 1159 PM 0.05" (60%) to 0.3" (30%) to 0.6" (15%) LOW Jefferson 200 PM TO 1159 PM 0.05" (60%) to 0.3" (30%) to 0.6" (15%) LOW Foothills above 6500ft       Boulder 100 PM TO 1100 PM 0.05" (75%) to 0.3" (50%) to 0.6" (25%) LOW Douglas 100 PM TO 1100 PM 0.05" (75%) to 0.3" (50%) to 0.6" (25%) LOW Jefferson 100 PM TO 1100 PM 0.05" (75%) to 0.3" (50%) to 0.6" (25%) 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]