Time: 420 PM Sun July 30, 2023 Forecaster: Justin Brooks ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- A FEW ISOLATED STORMS HAVE INITIATED ALONG EASTERN PORTIONS OF THE DISTRICT AT THIS TIME Message 1’s have been issued for the entire District effective until 9pm. A weak gust front collision east has initiated storms at this time, specifically around the Thornton/Brighton area. This storm has rapidly developed and will have the potential for moderate to heavy rainfall. This storm has the potential to produce additional gust fronts, similar to yesterday which could trigger additional storms, favoring eastern portions of the District through the evening. The largest storm threat will be a quick 0.5” in 10 minutes, however, a stronger storm that stalls out for an extended period should have no issue dumping over 1” per rainfall in 10-30 minutes as dew points remain elevated in some spots. Storms will taper off by sunset with skies gradually clearing through the overnight. Overnight lows will drop into the low 60’s along the plains with mid to upper 50’s along the foothills. STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers, weak thunderstorms will produce a 0.10-0.50” total in 10-30 minute. A moderate to strong thunderstorm will produce 0.50-1.20” total in 10-30 minutes. WORST CASE SCENARIO: A strong, anchored thunderstorm will have the potential to produce 2.00” in 45-60 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Arvada 1 Current TO 900 PM Current TO 830 PM Wheat Ridge 1 Current TO 900 PM Current TO 830 PM the City of Aurora 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 Denver County 1 Current TO 900 PM Current TO 830 PM Adams County 1 Current TO 900 PM Current TO 830 PM Douglas County 1 Current TO 900 PM Current TO 830 PM Broomfield County 1 Current TO 900 PM Current TO 830 PM Jefferson County 1 Current TO 900 PM Current TO 830 PM Boulder County 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 SUN 0.1" (60%) to 0.5" (30%) to 1.2" (15%) ISSUED Arapahoe Current TO 900 PM SUN 0.1" (60%) to 0.5" (30%) to 1.2" (15%) ISSUED Boulder Current TO 900 PM SUN 0.1" (60%) to 0.5" (30%) to 1.2" (15%) ISSUED Broomfield Current TO 900 PM SUN 0.1" (60%) to 0.5" (30%) to 1.2" (15%) ISSUED Denver Current TO 900 PM SUN 0.1" (60%) to 0.5" (30%) to 1.2" (15%) ISSUED Douglas Current TO 900 PM SUN 0.1" (60%) to 0.5" (30%) to 1.2" (15%) ISSUED Jefferson Current TO 900 PM SUN 0.1" (60%) to 0.5" (30%) to 1.2" (15%) ISSUED Foothills above 6500ft       Boulder Current TO 900 PM SUN 0.1" (50%) to 0.5" (25%) to 1.2" (10%) ISSUED Douglas Current TO 900 PM SUN 0.1" (50%) to 0.5" (25%) to 1.2" (10%) ISSUED Jefferson Current TO 900 PM SUN 0.1" (50%) to 0.5" (25%) to 1.2" (10%) 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]