Flash Flood Prediction Program

Message 1’s will continue to be valid as the threat of heavy rain remains until 10:00pm.

A few strong thunderstorms impacted eastern portions of the District earlier this afternoon and evening and have since moved eastward and onto the plains.

A slight chance remains for additional storm development through 10pm, as upper-level support will hold over the area over the next couple of days. However, cooler temperatures and losing daytime heating will result in a lower chance for additional thunderstorms.

Another chance for late evening showers, and off and on overnight showers into daybreak Friday. Quick storm motions, between 20-30mph will limit point rainfall amounts. Similar conditions remain in place Friday with another good chance for afternoon thunderstorms, with a slight chance for severe storms with large hail, winds 60+mph and even an isolated land spout/weak tornado or two.

STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers will produce TR-0.25” total in 10-30 minutes. A weak to moderate thunderstorm will produce 0.25-0.75” total in 10-30 minutes.

WORST CASE SCENARIO: A strong thunderstorm, or training of moderate thunderstorm cells has the potential to produce 1.50” in up to 60 minutes.

County	Message	Valid Times	Prime Time
the City of Aurora	1	Current TO 1000 PM	Current TO 900 PM
Arapahoe County	1	Current TO 1000 PM	Current TO 900 PM
DIA	1	Current TO 1000 PM	Current TO 900 PM
Denver County	1	Current TO 1000 PM	Current TO 900 PM
Adams County	1	Current TO 1000 PM	Current TO 900 PM
Douglas County	1	Current TO 1000 PM	Current TO 900 PM
Broomfield County	1	Current TO 1000 PM	Current TO 900 PM
Jefferson County	1	Current TO 1000 PM	Current TO 900 PM
Boulder County	1	Current TO 1000 PM	Current TO 900 PM
Arvada	1	Current TO 1000 PM	Current TO 900 PM
Wheat Ridge	1	Current TO 1000 PM	Current TO 900 PM
Lakewood	1	Current TO 1000 PM	Current TO 900 PM

County-specific Quantitative Precipitation Outlook	Precipitation Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	Current TO 1000 PM THU	Trace (50%) to 0.25" (25%) to 0.75" (10%)	ISSUED
Arapahoe	Current TO 1000 PM THU	Trace (50%) to 0.25" (25%) to 0.75" (10%)	ISSUED
Boulder	Current TO 1000 PM THU	Trace (50%) to 0.25" (25%) to 0.75" (10%)	ISSUED
Broomfield	Current TO 1000 PM THU	Trace (50%) to 0.25" (25%) to 0.75" (10%)	ISSUED
Denver	Current TO 1000 PM THU	Trace (50%) to 0.25" (25%) to 0.75" (10%)	ISSUED
Douglas	Current TO 1000 PM THU	Trace (50%) to 0.25" (25%) to 0.75" (10%)	ISSUED
Jefferson	Current TO 1000 PM THU	Trace (50%) to 0.25" (25%) to 0.75" (10%)	ISSUED
Foothills above 6500ft
Boulder	Current TO 1000 PM THU	Trace (50%) to 0.25" (25%) to 0.75" (10%)	ISSUED
Douglas	Current TO 1000 PM THU	Trace (50%) to 0.25" (25%) to 0.75" (10%)	ISSUED
Jefferson	Current TO 1000 PM THU	Trace (50%) to 0.25" (25%) to 0.75" (10%)	ISSUED

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.