Flash Flood Prediction Program

Time: 502 PM Mon May 29, 2023 Forecaster: Justin Brooks ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- GUST FRONT FROM THE SOUTHEAST HAS INCREASED STORM CHANCES THIS AFTERNOON A gust front from the southeast has moved into the District triggering a line of storms along north/northeastern portions of the District at this time. These storms will likely be pulse-like, with some moderate to brief heavy rain. The largest threat from these storms will be a quick 0.5” in 10-30 minutes, rather than any long-lasting rainfall. This will result in an increase to a LOW chance for Message 1’s to be issued this afternoon and into the early evening. The best chance for storms will be now through 8pm with skies gradually clearing as the sun sets. Overnight lows will dip into the upper 40’s to low 50’s on the plains with mid 40’s along the foothills. STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers and isolated weak thunderstorms will produce TR-0.25” in 10-30 minutes. A moderate to strong thunderstorm could produce 0.25-0.50” in 10-30 minutes. WORST CASE SCENARIO: A stationary thunderstorm formed along an outflow boundary, or training of moderate to heavy rain showers has the potential to produce up to 1.0” in 60 minutes. A LOOK AHEAD: Afternoon and evening storm chances will continue throughout the week, with likely a low threat for heavy rainfall in the upcoming days. Similar conditions remain in place tomorrow with high temperatures around 80 degrees. Best chance for storms will be the typical 2-8pm with chances decreasing into the later evening. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 800 PM MON Trace (50%) to 0.25" (25%) to 0.5" (10%) LOW Arapahoe Current TO 800 PM MON Trace (50%) to 0.25" (25%) to 0.5" (10%) LOW Boulder Current TO 800 PM MON Trace (50%) to 0.25" (25%) to 0.5" (10%) LOW Broomfield Current TO 800 PM MON Trace (50%) to 0.25" (25%) to 0.5" (10%) LOW Denver Current TO 800 PM MON Trace (50%) to 0.25" (25%) to 0.5" (10%) LOW Douglas Current TO 800 PM MON Trace (50%) to 0.25" (25%) to 0.5" (10%) LOW Jefferson Current TO 800 PM MON Trace (50%) to 0.25" (25%) to 0.5" (10%) LOW Foothills above 6500ft       Boulder Current TO 800 PM MON Trace (50%) to 0.25" (25%) to 0.5" (10%) LOW Douglas Current TO 800 PM MON Trace (50%) to 0.25" (25%) to 0.5" (10%) LOW Jefferson Current TO 800 PM MON Trace (50%) to 0.25" (25%) to 0.5" (10%) LOW MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS. MHFD Flood Prediction Center: 303-458-0789    F2P2 Website [http://udfcd.org/Flash+Flood+Prediction+Program]