Flash Flood Prediction Program

-	Message 1's have transitioned to Message 2's (NWS Flood/Flash Flood Watch) at 3:00 PM for Boulder and Douglas Counties and will be valid until 10:00 PM. Message 1's remain in effect for the remainder of the District and will also be valid until 10:00 PM. Message 1's and 2's may be extended until midnight if a flooding threat remains.
-	Thunderstorms are beginning to fill in over the area at this time with a SW to NE oriented line grazing SE portions of the District over Arapahoe and Douglas Counties. Additional storms lurk west. Scattered to numerous thunderstorms are expected through the remainder of the afternoon and into the early evening. Prime time for moderate to strong thunderstorms will until 9:00 PM.
-	Thunderstorms will be efficient rainfall producers very capable of producing heavy downpours that may lead to excessive runoff and possibly flash flooding.

STORM RAINFALL POTENTIAL AND DURATION: Weak thunderstorms will produce 0.3-0.8" in 10-30 minutes. Moderate to strong thunderstorms will have the potential to produce rainfall rates of 0.8-2.0 in 10-30 minutes.

WORST CASE SCENARIO: A large thunderstorm complex or a slower moving large thunderstorm may result in rainfall rates of 1.0-2.5" in 10-30 minutes and up to 3.5" in 45-75 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	2	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	2	Current TO 1000 PM	Current TO 900 PM
Lakewood	1	Current TO 1000 PM	Current TO 900 PM
Wheat Ridge	1	Current TO 1000 PM	Current TO 900 PM
Arvada	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 SUN	0.2" (95%) to 0.8" (70%) to 2.0" (20%)	ISSUED
Arapahoe	Current TO 1000 PM SUN	0.2" (100%) to 0.8" (75%) to 2.0" (30%)	ISSUED
Boulder	Current TO 1000 PM SUN	0.2" (95%) to 0.8" (70%) to 2.0" (20%)	ISSUED
Broomfield	Current TO 1000 PM SUN	0.2" (95%) to 0.8" (70%) to 2.0" (25%)	ISSUED
Denver	Current TO 1000 PM SUN	0.2" (95%) to 0.8" (70%) to 2.0" (20%)	ISSUED
Douglas	Current TO 1000 PM SUN	0.2" (100%) to 0.8" (75%) to 2.0" (30%)	ISSUED
Jefferson	Current TO 1000 PM SUN	0.2" (95%) to 0.8" (70%) to 2.0" (20%)	ISSUED
Foothills above 6500ft
Boulder	Current TO 1000 PM SUN	0.2" (100%) to 0.8" (75%) to 2.0" (25%)	ISSUED
Douglas	Current TO 1000 PM SUN	0.2" (100%) to 0.8" (75%) to 2.0" (30%)	ISSUED
Jefferson	Current TO 1000 PM SUN	0.2" (100%) to 0.8" (75%) to 2.0" (25%)	ISSUED

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.