Time: 149 PM Sat July 27, 2024 Forecaster: Justin Brooks ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 1’S HAVE BEEN ISSUED EFFECTIVEUNTIL 9:00 PM Storms have already started to impact portions of the foothills just outside of the District. The best chance for storm activity within the District 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 10-15mph, with some erratic storm motions likely from outflow boundaries. This will result in some storms having the potential to anchor in place with a threat for moderate to heavy rainfall. A quick 0.50”-0.80” in 10-30 minutes is expected rather than any long lasting rainfall. 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 past sundown, although the threat of heavy rainfall will likely subside by 8-9pm this evening. 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”-0.80” 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 1.20” of rain in 30-60 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Boulder County 1 Current TO 900 PM Current TO 830 PM Jefferson County 1 Current TO 900 PM Current TO 830 PM Broomfield County 1 Current TO 900 PM Current TO 830 PM Douglas County 1 Current TO 900 PM Current TO 830 PM Adams County 1 Current TO 900 PM Current TO 830 PM Denver County 1 Current TO 900 PM Current TO 830 PM DIA 1 Current TO 900 PM Current TO 830 PM Arapahoe County 1 Current TO 900 PM Current TO 830 PM the City of Aurora 1 Current TO 900 PM Current TO 830 PM Arvada 1 Current TO 900 PM Current TO 830 PM Wheat Ridge 1 Current TO 900 PM Current TO 830 PM Lakewood 1 Current TO 900 PM Current TO 830 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 900 PM SAT 0.05" (60%) to 0.3" (30%) to 0.8" (15%) ISSUED Arapahoe Current TO 900 PM SAT 0.05" (60%) to 0.3" (30%) to 0.8" (15%) ISSUED Boulder Current TO 900 PM SAT 0.05" (60%) to 0.3" (30%) to 0.8" (15%) ISSUED Broomfield Current TO 900 PM SAT 0.05" (60%) to 0.3" (30%) to 0.8" (15%) ISSUED Denver Current TO 900 PM SAT 0.05" (60%) to 0.3" (30%) to 0.8" (15%) ISSUED Douglas Current TO 900 PM SAT 0.05" (60%) to 0.3" (30%) to 0.8" (15%) ISSUED Jefferson Current TO 900 PM SAT 0.05" (60%) to 0.3" (30%) to 0.8" (15%) ISSUED Foothills above 6500ft       Boulder Current TO 900 PM SAT 0.05" (75%) to 0.3" (50%) to 0.8" (25%) ISSUED Douglas Current TO 900 PM SAT 0.05" (75%) to 0.3" (50%) to 0.8" (25%) ISSUED Jefferson Current TO 900 PM SAT 0.05" (75%) to 0.3" (50%) to 0.8" (25%) 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]