Flash Flood Prediction Program

Time: 903 AM Mon August 28, 2023 Forecaster: Laura Smith ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- HOT SUMMERTIME CONDITIONS WITH ISOLATED TO SCATTERED THUNDERSTORMS As the remnants of a tropical system continue to shift east into the District, showers and thunderstorms along the Front Range Urban Corridor are expected today and tonight. Isolated to scattered storm activity is expected across the District today as afternoon temperatures reach the upper 70s to low 80s, dew points in the low to mid 50s, and precipitable water (PWAT) values between 0.85” to 1.00”. Storms are expected to move southeast around 25-30 mph. Quick storm motions will help limit point rainfall amounts. Thunderstorms are expected to continue this evening, then move east overnight. STORM RAINFALL POTENTIAL AND DURATION: Typical showers will produce rainfall of TR-0.25” total in 10-30 minutes. Stronger storms have the potential to produce heavy rainfall of 0.25” to 0.75” total in 10-30 minutes. WORST CASE SCENARIO: Training or anchored thunderstorms have the potential to produce 0.75” to 1.25” total in 30-60 minutes. A LOOK AHEAD: Upper-level winds will shift tomorrow, transporting much dryer and warmer conditions into the state. Tomorrow will be sunny with afternoon temperatures warming into the low to mid 80s. Thunderstorm activity will be broadly limited to complex terrain. The remainder of the week is expected to be dry and hot, with afternoon temperatures climbing into the 90s under sunny skies. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 200 PM TO 900 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Arapahoe 200 PM TO 900 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Boulder 200 PM TO 900 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Broomfield 200 PM TO 900 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Denver 200 PM TO 900 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Douglas 200 PM TO 900 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Jefferson 200 PM TO 900 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Foothills above 6500ft       Boulder 200 PM TO 900 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Douglas 200 PM TO 900 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Jefferson 200 PM TO 900 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS. MHFD Flood Prediction Center: 303-458-0789    F2P2 Website [http://udfcd.org/Flash+Flood+Prediction+Program]