Time: 1215 PM Fri July 26, 2024 Forecaster: Justin Brooks ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1’S HAVE BEEN ISSUED EFFECTIVE UNTIL10:00 PM Storms have already started to impact areas along the foothills just outside of the District where a few moderate showers have already produced rainfall rates between 0.30”-0.50” in 10-15 minutes. The best chance for storm activity today will begin over the next hour with a chance for storms lasting into the evening hours. Storm motions will generally be west to east between 10-20mph, with some erratic storm motions likely from outflow boundaries. This will result in some storms having the potential to anchor in place supporting clustering thunderstorms with a threat for moderate to heavy rainfall. A quick 0.50”-0.80” in 10-20 minutes is expected, along with the possibility for over 1.0” of rain per hour if a stronger storm stalls over the District. Storms today may also contain hail up to 1.0”, gusty winds up to 50mph and frequent cloud-to-ground lightning. A slight chance of showers lingers through midnight, although the threat of heavy rainfall will likely subside by 10pm this evening. A few off and on showers may persist through midnight with skies gradually clearing overnight tonight. Overnight temperatures will drop into the low 60s for the plains with mid to upper 50s along the foothills. STORM RAINFALL POTENTIAL AND DURATION: Typical showers will produce 0.05-0.30" total in 10-30 minutes. A moderate to strong thunderstorm will produce rainfall rates of 0.30”-0.60” total in 10-30 minutes. WORST CASE SCENARIO: A slow-moving thunderstorm, training of thunderstorms cells or a large thunderstorm complex may result in up to 1.25” of rain in 30-60 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Lakewood 1 Current TO 1000 PM Current TO 930 PM Wheat Ridge 1 Current TO 1000 PM Current TO 930 PM Arvada 1 Current TO 1000 PM Current TO 930 PM the City of Aurora 1 Current TO 1000 PM Current TO 930 PM Arapahoe County 1 Current TO 1000 PM Current TO 930 PM DIA 1 Current TO 1000 PM Current TO 930 PM Denver County 1 Current TO 1000 PM Current TO 930 PM Adams County 1 Current TO 1000 PM Current TO 930 PM Douglas County 1 Current TO 1000 PM Current TO 930 PM Broomfield County 1 Current TO 1000 PM Current TO 930 PM Jefferson County 1 Current TO 1000 PM Current TO 930 PM Boulder County 1 Current TO 1000 PM Current TO 930 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 1000 PM FRI 0.05" (60%) to 0.3" (40%) to 0.8" (20%) ISSUED Arapahoe Current TO 1000 PM FRI 0.05" (60%) to 0.3" (40%) to 0.8" (20%) ISSUED Boulder Current TO 1000 PM FRI 0.05" (60%) to 0.3" (40%) to 0.8" (20%) ISSUED Broomfield Current TO 1000 PM FRI 0.05" (60%) to 0.3" (40%) to 0.8" (20%) ISSUED Denver Current TO 1000 PM FRI 0.05" (60%) to 0.3" (40%) to 0.8" (20%) ISSUED Douglas Current TO 1000 PM FRI 0.05" (60%) to 0.3" (40%) to 0.8" (20%) ISSUED Jefferson Current TO 1000 PM FRI 0.05" (60%) to 0.3" (40%) to 0.8" (20%) ISSUED Foothills above 6500ft       Boulder Current TO 1000 PM FRI 0.05" (90%) to 0.3" (60%) to 0.8" (30%) ISSUED Douglas Current TO 1000 PM FRI 0.05" (90%) to 0.3" (60%) to 0.8" (30%) ISSUED Jefferson Current TO 1000 PM FRI 0.05" (90%) to 0.3" (60%) to 0.8" (30%) ISSUED MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS. MHFD Flood Prediction Center: 303-458-0789    F2P2 Website [http://udfcd.org/Flash+Flood+Prediction+Program]