Flash Flood Prediction Program

Time: 1001 AM Fri June 21, 2024 Forecaster: Laura Smith ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- Showers and Thunderstorms expected this afternoon and evening An upper-level disturbance over the Great Basin will be responsible for another round of thunderstorms today. Morning cloud cover will support slightly cooler temperatures this afternoon. Highs will reach the mid to upper 80s, with a few areas breaking 90°F. Atmospheric moisture remains elevated with steering winds aloft from the southwest. Dewpoints will be in the low to mid 50s with precipitable water (PWAT) values around 0.85”. Convection initiation is expected during the early afternoon, with chances for showers and thunderstorms continuing into the evening. Storms will generally move east-northeast between 25-30 mph. Thunderstorm activity is expected to dissipate by mid-evening. STORM RAINFALL POTENTIAL AND DURATION: Thunderstorms today have the potential to produce up to 0.75” in 10-30 minutes. WORST CASE SCENARIO: Strong thunderstorms may be capable of producing 1.50” to 2.00” in 60 minutes or less. A LOOK AHEAD: High pressure ridging begins building across the four-corners region overnight, supporting hot and mostly dry conditions through the weekend and into early next week. On Saturday, afternoon highs will reach the upper 80s to low 90s under sunny skies. Sunday will be hot, sunny, and dry with highs in the low to mid 90s. Monday will be dry and exceptionally hot as temperatures soar into the upper 90s. Some areas may reach or exceed 100°F. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 200 PM TO 800 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Arapahoe 200 PM TO 800 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Boulder 200 PM TO 800 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Broomfield 200 PM TO 800 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Denver 200 PM TO 800 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Douglas 200 PM TO 800 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Jefferson 200 PM TO 800 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Foothills above 6500ft       Boulder 100 PM TO 700 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Douglas 100 PM TO 700 PM 0.25" (75%) to 0.5" (50%) to 0.75" (25%) MOD Jefferson 100 PM TO 700 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]