Flash Flood Prediction Program

-	Message 1's have been issued for the entire District and will be valid from 1:00pm until 9:00pm this evening.
-	An approaching upper level disturbance is expected to result in a round or two of thunderstorms this afternoon and early evening. Storms that develop today will be very capable of producing heavy rainfall that may lead to excessive runoff and flash flooding. Storms will be slow moving as upper level steering winds are light from NW to SE at 5-10mph. Outflow boundaries and gust fronts may act to briefly anchor storms and may result in erratic storm motions at times.
-	After 9pm the threat for thunderstorm activity decreases but another round of showers is expected to move through and be in the area until around midnight. If the late evening round of showers also contains thunderstorm activity then Message 1's may need to be extended until midnight.

STORM RAINFALL POTENTIAL AND DURATION: Weak to moderate thunderstorms will produce 0.1-0.4" of rainfall. Strong thunderstorms will have the potential to produce 0.4-1.2" in 10-30 minutes.

WORST CASE SCENARIO: A nearly stationary strong thunderstorm may result in up to 2.5" of heavy rain in 45-60 minutes.

County	Message	Valid Times	Prime Time
Boulder County	1	100 PM TO 900 PM	200 PM TO 800 PM
Jefferson County	1	100 PM TO 900 PM	200 PM TO 800 PM
Broomfield County	1	100 PM TO 900 PM	300 PM TO 800 PM
Douglas County	1	100 PM TO 900 PM	200 PM TO 800 PM
Adams County	1	100 PM TO 900 PM	300 PM TO 800 PM
Denver County	1	100 PM TO 900 PM	300 PM TO 800 PM
DIA	1	100 PM TO 900 PM	300 PM TO 800 PM
Arapahoe County	1	100 PM TO 900 PM	300 PM TO 800 PM
the City of Aurora	1	100 PM TO 900 PM	300 PM TO 800 PM
Arvada	1	100 PM TO 900 PM	300 PM TO 800 PM
Wheat Ridge	1	100 PM TO 900 PM	300 PM TO 800 PM
Lakewood	1	100 PM TO 900 PM	300 PM TO 800 PM

County-specific Quantitative Precipitation Outlook	Precipitation Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	300 PM TO 900 PM	0.1" (90%) to 0.4" (60%) to 1.2" (30%)	ISSUED
Arapahoe	300 PM TO 900 PM	0.1" (90%) to 0.4" (60%) to 1.2" (30%)	ISSUED
Broomfield	300 PM TO 900 PM	0.1" (90%) to 0.4" (60%) to 1.2" (30%)	ISSUED
Denver	300 PM TO 900 PM	0.1" (90%) to 0.4" (60%) to 1.2" (30%)	ISSUED
Boulder	200 PM TO 900 PM	0.1" (90%) to 0.4" (60%) to 1.2" (30%)	ISSUED
Douglas	200 PM TO 900 PM	0.1" (90%) to 0.4" (60%) to 1.2" (30%)	ISSUED
Jefferson	200 PM TO 900 PM	0.1" (90%) to 0.4" (60%) to 1.2" (30%)	ISSUED
Foothills above 6500ft
Boulder	100 PM TO 900 PM	0.1" (95%) to 0.4" (65%) to 1.2" (30%)	ISSUED
Douglas	100 PM TO 900 PM	0.1" (95%) to 0.4" (65%) to 1.2" (30%)	ISSUED
Jefferson	100 PM TO 900 PM	0.1" (95%) to 0.4" (65%) to 1.2" (30%)	ISSUED

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.