Time: 811 AM Sat June 17, 2023 Forecaster: Justin Brooks ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- PARTLY CLOUDY & COOL TO START THE DAY WITH ANOTHER CHANCE FOR AFTERNOON SHOWERS/THUNDERSTORMS Another disturbance is currently moving towards the region and will quickly progress eastward through the day. Cool and cloudy to start the morning, could very well suppress storm intensities again this afternoon. However, a better chance the sun pokes through today resulting in a good chance for rain showers and thunderstorms this afternoon. Elevated surface moisture remains in place across the District, with heavy rainfall expected out of any thunderstorms that do develop. This has resulted in a Flood Watch to be issued for parts of Douglas County, including NE Highlands Ranch and Parker. This Flood Watch is in effect from Noon today until 6pm. A Message 2 Will be issued for this today, likely coinciding with Message 1’s for the remainder of the District during this same timeframe, possibly sooner and extending later, depending on the dynamics as the morning progresses. Storm motions should also help limit point rainfall amounts today, with NW to SE storm movements between 10-15mph, with some erratic storm motions possible if stronger storms are able to develop which will likely produce outflow boundaries. The outflow storms will be the most likely to produce a quick 0.5-1.25” in 10-30 minutes today. Storms look to exit the District by 6 or 7pm this evening with conditions drying out through the overnight tonight. STORM RAINFALL POTENTIAL AND DURATION: Typical showers and weak thunderstorms will produce a 0.10-0.50” total, in 10-30 minutes. A moderate to strong thunderstorm will produce 0.50-1.25” total, in 10-30 minutes. WORST CASE SCENARIO: A stronger thunderstorm, or training of moderate showers/thunderstorms will have the potential to produce 2.0” total in under 60 minutes. A LOOK AHEAD: Tomorrow starts to warm to a more seasonable upper 70’s to around 80 degrees tomorrow with our first dry day in a very long time! A high-pressure ridge will start to build over the next few days bringing warm and dry conditions through most of the week! Tuesday we will even flirt with our first 90 degree day this year as temperatures rapidly increase under mostly sunny skies. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 1200 PM TO 600 PM 0.1" (75%) to 0.5" (50%) to 1.25" (25%) HIGH Arapahoe 1200 PM TO 600 PM 0.1" (75%) to 0.5" (50%) to 1.25" (25%) HIGH Boulder 1200 PM TO 600 PM 0.1" (75%) to 0.5" (50%) to 1.25" (25%) HIGH Broomfield 1200 PM TO 600 PM 0.1" (75%) to 0.5" (50%) to 1.25" (25%) HIGH Denver 1200 PM TO 600 PM 0.1" (75%) to 0.5" (50%) to 1.25" (25%) HIGH Douglas 1200 PM TO 600 PM 0.1" (90%) to 0.5" (60%) to 1.25" (40%) HIGH Jefferson 1200 PM TO 600 PM 0.1" (80%) to 0.5" (50%) to 1.25" (30%) HIGH Foothills above 6500ft       Boulder 1200 PM TO 600 PM 0.1" (75%) to 0.5" (50%) to 1.25" (25%) HIGH Douglas 1200 PM TO 600 PM 0.1" (90%) to 0.5" (60%) to 1.25" (40%) HIGH Jefferson 1200 PM TO 600 PM 0.1" (80%) to 0.5" (50%) to 1.25" (30%) HIGH MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS. MHFD Flood Prediction Center: 303-458-0789    F2P2 Website [http://udfcd.org/Flash+Flood+Prediction+Program]