Flash Flood Prediction Program

-	Message 2's (NWS Flash Flood/Flood Watch) have been issued for Boulder, Broomfield and Jefferson Counties valid 11:00 AM until 10:00 PM. Message 1's have been issued for the remainder of the District to coincide with Message 2's effective 11:00 AM until 10:00 PM this evening.
-	Cooler and cloudy today after another overnight heavy rainfall threat. An excess of available moisture at the surface and upper-levels combined with a disturbance that will move through this afternoon has brought an increased threat for widespread heavy rainfall. Rain showers and thunderstorms will fist develop along the higher terrain between now till noon with storms likely moving into the District between noon and 1pm. Prime time for moderate to strong thunderstorms will be until 9 or 10pm before skies gradually clear into the overnight with minimal rainfall expected past midnight tonight.
-	Thunderstorms will be efficient rainfall producers very capable of producing heavy downpours that may lead to excessive runoff and possibly flash flooding. Storms will be relatively slow moving from W to E between 5-10mph, with a chance some storms may anchor in place leading to an increase chance for isolated long lasting moderate to heavy rainfall.

STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers/thunderstorms will produce 0.3-1.0" in 10-30 minutes. Moderate to strong thunderstorms will have the potential to produce rainfall rates of 1.0-2.0 in 10-30 minutes.

WORST CASE SCENARIO: A strong anchored thunderstorm or training of moderate to strong thunderstorms may result in rainfall rates up to 3.0" in 45-75 minutes.

County	Message	Valid Times	Prime Time
Douglas County	1	1100 AM TO 1000 PM	1100 AM TO 1000 PM
Broomfield County	2	1100 AM TO 1000 PM	1100 AM TO 1000 PM
Jefferson County	2	1100 AM TO 1000 PM	1100 AM TO 1000 PM
Boulder County	2	1100 AM TO 1000 PM	1100 AM TO 1000 PM
Lakewood	2	1100 AM TO 1000 PM	1100 AM TO 1000 PM
Wheat Ridge	2	1100 AM TO 1000 PM	1100 AM TO 1000 PM
Arvada	2	1100 AM TO 1000 PM	1100 AM TO 1000 PM
the City of Aurora	1	1100 AM TO 1000 PM	1100 AM TO 1000 PM
Arapahoe County	1	1100 AM TO 1000 PM	1100 AM TO 1000 PM
DIA	1	1100 AM TO 1000 PM	1100 AM TO 1000 PM
Denver County	1	1100 AM TO 1000 PM	1100 AM TO 1000 PM
Adams County	1	1100 AM TO 1000 PM	1100 AM TO 1000 PM

County-specific Quantitative Precipitation Outlook	Precipitation Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	1100 AM TO 1159 PM	0.3" (90%) to 1.0" (45%) to 2.0" (20%)	ISSUED
Arapahoe	1100 AM TO 1159 PM	0.3" (90%) to 1.0" (45%) to 2.0" (20%)	ISSUED
Boulder	1100 AM TO 1159 PM	0.3" (90%) to 1.0" (45%) to 2.0" (20%)	ISSUED
Broomfield	1100 AM TO 1159 PM	0.3" (90%) to 1.0" (45%) to 2.0" (20%)	ISSUED
Denver	1100 AM TO 1159 PM	0.3" (90%) to 1.0" (45%) to 2.0" (20%)	ISSUED
Douglas	1100 AM TO 1159 PM	0.3" (90%) to 1.0" (45%) to 2.0" (20%)	ISSUED
Jefferson	1100 AM TO 1159 PM	0.3" (90%) to 1.0" (45%) to 2.0" (20%)	ISSUED
Foothills above 6500ft
Boulder	1100 AM TO 1159 PM	0.3" (95%) to 1.0" (50%) to 2.0" (25%)	ISSUED
Douglas	1100 AM TO 1159 PM	0.3" (95%) to 1.0" (50%) to 2.0" (25%)	ISSUED
Jefferson	1100 AM TO 1159 PM	0.3" (95%) to 1.0" (50%) to 2.0" (25%)	ISSUED

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.