Time: 914 AM Fri August 25, 2023 Forecaster: Justin Brooks ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 2’S HAVE BEEN ISSUED EFFECTIVE UNTIL 12:00 PM SATURDAY AUGUST 26TH Message 2’s have been issued for the entire District effective until 12:00pm, Saturday August, 26th as there will be a threat of heavy rainfall today, through this evening/overnight and through midday tomorrow. Remnants of a tropical system have moved over the region today and will result in a good chance of heavy rainfall across the District. A few isolated storms have already impacted eastern portions of the District and continue to impact the area at this time. Storm coverage will increase through the morning with widespread rainfall possible by midday today. With an abundance of moisture in place, most if not all storms will be efficient rain producers. Stronger storms will have a good chance of heavy rainfall, combined with relatively slow storm motions could result in rainfall rates between 1-2” per hour at times. The best chance for storms today will be between noon and 8pm today, with storms likely decreasing in intensities after sundown. A chance linger showers remain through the overnight and into tomorrow, with an already saturated ground will keep a chance for flooding into tomorrow as off and on showers likely persist through the morning hours Saturday. STORM RAINFALL POTENTIAL AND DURATION: Typical showers/weak thunderstorms will produce a 0.25-0.75” total, in 10-30 minutes. A moderate to strong shower/thunderstorm will produce 0.75-1.25” 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 2.00” total in 60-90 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Boulder County 2 900 AM TO 1200 PM SATURDAY 900 AM TO 1200 PM SATURDAY Jefferson County 2 900 AM TO 1200 PM SATURDAY 900 AM TO 1200 PM SATURDAY Broomfield County 2 900 AM TO 1200 PM SATURDAY 900 AM TO 1200 PM SATURDAY Douglas County 2 900 AM TO 1200 PM SATURDAY 900 AM TO 1200 PM SATURDAY Adams County 2 900 AM TO 1200 PM SATURDAY 900 AM TO 1200 PM SATURDAY Denver County 2 900 AM TO 1200 PM SATURDAY 900 AM TO 1200 PM SATURDAY DIA 2 900 AM TO 1200 PM SATURDAY 900 AM TO 1200 PM SATURDAY Arapahoe County 2 900 AM TO 1200 PM SATURDAY 900 AM TO 1200 PM SATURDAY the City of Aurora 2 900 AM TO 1200 PM SATURDAY 900 AM TO 1200 PM SATURDAY Arvada 2 900 AM TO 1200 PM SATURDAY 900 AM TO 1200 PM SATURDAY Wheat Ridge 2 900 AM TO 1200 PM SATURDAY 900 AM TO 1200 PM SATURDAY Lakewood 2 900 AM TO 1200 PM SATURDAY 900 AM TO 1200 PM SATURDAY County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 900 AM TO 1200 PM SAT 0.25" (90%) to 0.75" (60%) to 1.25" (30%) ISSUED Arapahoe 900 AM TO 1200 PM SAT 0.25" (90%) to 0.75" (60%) to 1.25" (30%) ISSUED Boulder 900 AM TO 1200 PM SAT 0.25" (90%) to 0.75" (60%) to 1.25" (30%) ISSUED Broomfield 900 AM TO 1200 PM SAT 0.25" (90%) to 0.75" (60%) to 1.25" (30%) ISSUED Denver 900 AM TO 1200 PM SAT 0.25" (90%) to 0.75" (60%) to 1.25" (30%) ISSUED Douglas 900 AM TO 1200 PM SAT 0.25" (90%) to 0.75" (60%) to 1.25" (30%) ISSUED Jefferson 900 AM TO 1200 PM SAT 0.25" (90%) to 0.75" (60%) to 1.25" (30%) ISSUED Foothills above 6500ft       Boulder 900 AM TO 1200 PM SAT 0.25" (90%) to 0.75" (60%) to 1.25" (30%) ISSUED Douglas 900 AM TO 1200 PM SAT 0.25" (90%) to 0.75" (60%) to 1.25" (30%) ISSUED Jefferson 900 AM TO 1200 PM SAT 0.25" (90%) to 0.75" (60%) to 1.25" (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]