Flash Flood Prediction Program

-	Message 1's have been issued for the entire District and will be valid until 8pm this evening.
-	Thunderstorms are developing to the S and W of the District currently and are expected to fill in over the District over the next 1-2hours. A round of scattered moderate to strong thunderstorms is then expected to impact portions of the District through the early evening.
-	Thunderstorms will be slow moving from SW to NE at around 10mph and will have the potential to produce extended periods of heavy rainfall that may lead to excessive runoff and possibly flash flooding. Strong thunderstorms may move more erratically along gust fronts/outflow boundaries or remain nearly stationary. Strong thunderstorms may also contain large hail, frequent cloud-to-ground lightning and damaging winds.

STORM RAINFALL POTENTIAL AND DURATION: Typical weak to moderate thunderstorms will produce 0.1-0.4" in 10-30 minutes. Strong thunderstorms will have the potential to produce 0.5-1.3" in 10-30 minutes.

WORST CASE SCENARIO: A large thunderstorm complex or a nearly stationary strong thunderstorm may produce up to 2.5" in 60 minutes or less.

County	Message	Valid Times	Prime Time
Arapahoe County	1	Current TO 800 PM	300 PM TO 700 PM
DIA	1	Current TO 800 PM	300 PM TO 700 PM
Denver County	1	Current TO 800 PM	300 PM TO 700 PM
Adams County	1	Current TO 800 PM	300 PM TO 700 PM
Douglas County	1	Current TO 800 PM	300 PM TO 700 PM
Broomfield County	1	Current TO 800 PM	300 PM TO 700 PM
Jefferson County	1	Current TO 800 PM	300 PM TO 700 PM
Boulder County	1	Current TO 800 PM	300 PM TO 700 PM
Lakewood	1	Current TO 800 PM	300 PM TO 700 PM
Wheat Ridge	1	Current TO 800 PM	300 PM TO 700 PM
the City of Aurora	1	Current TO 800 PM	300 PM TO 700 PM
Arvada	1	Current TO 800 PM	300 PM TO 700 PM

County-specific Quantitative Precipitation Outlook	Precipitation Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	300 PM TO 800 PM	0.1" (75%) to 0.4" (40%) to 1.3" (15%)	ISSUED
Arapahoe	300 PM TO 800 PM	0.1" (90%) to 0.4" (60%) to 1.3" (20%)	ISSUED
Boulder	300 PM TO 800 PM	0.1" (75%) to 0.4" (40%) to 1.3" (15%)	ISSUED
Broomfield	300 PM TO 800 PM	0.1" (75%) to 0.4" (40%) to 1.3" (15%)	ISSUED
Denver	300 PM TO 800 PM	0.1" (80%) to 0.4" (50%) to 1.3" (20%)	ISSUED
Jefferson	230 PM TO 800 PM	0.1" (80%) to 0.4" (50%) to 1.3" (20%)	ISSUED
Douglas	Current TO 800 PM FRI	0.1" (90%) to 0.4" (60%) to 1.3" (20%)	ISSUED
Foothills above 6500ft
Boulder	230 PM TO 800 PM	0.1" (80%) to 0.4" (50%) to 1.3" (15%)	ISSUED
Douglas	Current TO 800 PM FRI	0.1" (95%) to 0.4" (65%) to 1.3" (20%)	ISSUED
Jefferson	Current TO 800 PM FRI	0.1" (90%) to 0.4" (60%) to 1.3" (20%)	ISSUED

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.