Flash Flood Prediction Program

Time: 1038 AM Thu May 30, 2024 Forecaster: Justin Brooks ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- Another chance for showers/isolated thunderstorms this afternoon and evening. Very little change to the upper-level dynamics today, combined with a slight uptick in the available moisture at the surface this morning will bring another chance for afternoon showers and isolated thunderstorms. There will be a slight chance some of these storms will become severe, mainly for gusty winds and hail up to 1.0” for areas east of I-25 at this time. Storms will initiate along the higher terrain in the early afternoon with the best chance for storms withing the District between 2-8pm today. Storm motions will be from west to east between 15-20mph which will help limit point rainfall amounts, however, some erratic storm motions will be possible due to outflow boundaries. These erratic storms will have the highest potential for heavy rainfall with the largest threat today being a quick 0.6” in 10-15min rather than any long-lasting rainfall. Another slight chance for a few lingering showers into the later evening and possibly overnight, although the threat of heavy rainfall should diminish after sunset. Overnight will be partly cloudy out as temperatures dip into the low to mid 50s for the plains by daybreak tomorrow, with upper 40s to around 50 for the foothills. STORM RAINFALL POTENTIAL AND DURATION: Typical showers and isolated thunderstorms will produce 0.05-0.30” total in 10-30 minutes. A moderate shower/thunderstorm will produce 0.30”-0.60” total in 10-30 minutes. WORST CASE SCENARIO: A strong thunderstorm, or a stationary storm will have the potential to produce up to 1.20” total in 10-30 minutes. A LOOK AHEAD: Slightly drier air overall tomorrow will decrease the chance for showers and thunderstorm threat, however, an abundance of left over moisture at the surface from any rainfall today will likely result in at least a LOW chance for Messages to be issued. Temperatures tomorrow will remain in the mid to upper 70s. Saturday will likely dry out completely as high-pressure starts to creep back into the state. This will bring high temperatures back into the low to mid 80s under mostly sunny skies. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 200 PM TO 800 PM 0.05" (70%) to 0.3" (35%) to 0.6" (20%) LOW Arapahoe 200 PM TO 800 PM 0.05" (70%) to 0.3" (35%) to 0.6" (20%) LOW Boulder 200 PM TO 800 PM 0.05" (60%) to 0.3" (30%) to 0.6" (10%) LOW Broomfield 200 PM TO 800 PM 0.05" (60%) to 0.3" (30%) to 0.6" (10%) LOW Denver 200 PM TO 800 PM 0.05" (70%) to 0.3" (35%) to 0.6" (20%) LOW Douglas 200 PM TO 800 PM 0.05" (60%) to 0.3" (30%) to 0.6" (10%) LOW Jefferson 200 PM TO 800 PM 0.05" (60%) to 0.3" (30%) to 0.6" (10%) LOW Foothills above 6500ft       Boulder 200 PM TO 800 PM 0.05" (50%) to 0.3" (25%) to 0.6" (5%) LOW Douglas 200 PM TO 800 PM 0.05" (50%) to 0.3" (25%) to 0.6" (5%) LOW Jefferson 200 PM TO 800 PM 0.05" (50%) to 0.3" (25%) to 0.6" (5%) 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]