Flash Flood Prediction Program

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.