Flash Flood Prediction Program

-	Message 1's have been issued for the entire District and will remain valid until 9:00 pm this evening.
-	Thunderstorms are beginning to develop over the higher terrain to the W of the District at this time. These initial storms will move into a relatively stable air mass keeping the threat for heavy rainfall over the higher terrain initially and a lesser chance plains but as the afternoon wears on and temperatures continue to warm and outflow from initial storms move onto the plains additional thunderstorms are expected to develop.
-	Relatively fast storm motions from W to E at 20-25mph will help to lower point rainfall amounts from a single weak to moderate storm. Stronger thunderstorms may develop along outflow boundaries/gust fronts and may move more slowly or anchor briefly potentially producing an extended period of heavy rainfall.

STORM RAINFALL POTENTIAL AND DURATION: Weak to moderate thunderstorms will produce 0.4-1.0" in 10-30 minutes.

WORST CASE SCENARIO: A slow moving, briefly stationary strong thunderstorm may produce up to 2.0" in 45-75 minutes.

County	Message	Valid Times	Prime Time
Boulder County	1	Current TO 900 PM	130 PM TO 800 PM
Jefferson County	1	Current TO 900 PM	100 PM TO 800 PM
Broomfield County	1	Current TO 900 PM	200 PM TO 800 PM
Douglas County	1	Current TO 900 PM	130 PM TO 800 PM
Adams County	1	Current TO 900 PM	200 PM TO 800 PM
Denver County	1	Current TO 900 PM	200 PM TO 800 PM
DIA	1	Current TO 900 PM	200 PM TO 800 PM
Arapahoe County	1	Current TO 900 PM	200 PM TO 800 PM
the City of Aurora	1	Current TO 900 PM	200 PM TO 800 PM
Arvada	1	Current TO 900 PM	200 PM TO 800 PM
Wheat Ridge	1	Current TO 900 PM	200 PM TO 800 PM
Lakewood	1	Current TO 900 PM	200 PM TO 800 PM

County-specific Quantitative Precipitation Outlook	Precipitation Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	100 PM TO 900 PM	0.1" (75%) to 0.4" (40%) to 1.0" (15%)	ISSUED
Arapahoe	100 PM TO 900 PM	0.1" (80%) to 0.4" (50%) to 1.0" (20%)	ISSUED
Boulder	100 PM TO 900 PM	0.1" (75%) to 0.4" (40%) to 1.0" (15%)	ISSUED
Broomfield	100 PM TO 900 PM	0.1" (75%) to 0.4" (40%) to 1.0" (15%)	ISSUED
Denver	100 PM TO 900 PM	0.1" (75%) to 0.4" (40%) to 1.0" (15%)	ISSUED
Douglas	100 PM TO 900 PM	0.1" (85%) to 0.4" (50%) to 1.0" (20%)	ISSUED
Jefferson	100 PM TO 900 PM	0.1" (75%) to 0.4" (40%) to 1.0" (15%)	ISSUED
Foothills above 6500ft
Boulder	Current TO 900 PM TUE	0.1" (90%) to 0.4" (50%) to 1.0" (15%)	ISSUED
Douglas	Current TO 900 PM TUE	0.1" (90%) to 0.4" (50%) to 1.0" (15%)	ISSUED
Jefferson	Current TO 900 PM TUE	0.1" (90%) to 0.4" (50%) to 1.0" (15%)	ISSUED

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.