Flash Flood Prediction Program

-	Message 1's have been issued for all of the District and will be valid until 10:00pm this evening. With a moist atmosphere in place in tandem with slow storm motions thunderstorms that develop later today will be very capable of producing heavy rainfall that may lead to excessive runoff and possibly flash flooding.
-	Showers and weak thunderstorms are currently developing over portions of southern Jefferson and western Douglas Counties. Shower and thunderstorm coverage is expected to expand northward and eventually eastward as the afternoon progresses. Storm motions will be slow, at 10mph or less and thunderstorms may have a tendency to anchor or move very slowly potentially producing moderate to heavy rainfall for an extended period of time.
-	Best chances for thunderstorm activity looks to be from 2-8pm over the foothills and from 4-9pm over the plains. There still remains uncertainty on the potential strength of thunderstorms this afternoon as daytime heating or lack there of over the next few hours will play a major role.

STORM RAINFALL POTENTIAL AND DURATION: Rain showers and weak thunderstorms will produce 0.1-0.4" in 10-30 minutes. Moderate to strong thunderstorms. Moderate to strong thunderstorms will have the potential to produce 0.4-1.0" in 10-30 minutes.

WORST CASE SCENARIO: A strong thunderstorm becomes stationary producing an extended period of heavy rainfall with up to 2.0" in 60 minutes or less.

County	Message	Valid Times	Prime Time
Boulder County	1	Current TO 1000 PM	400 PM TO 900 PM
Jefferson County	1	Current TO 1000 PM	200 PM TO 900 PM
Broomfield County	1	Current TO 1000 PM	300 PM TO 900 PM
Douglas County	1	Current TO 1000 PM	200 PM TO 900 PM
Adams County	1	Current TO 1000 PM	400 PM TO 900 PM
Denver County	1	Current TO 1000 PM	400 PM TO 900 PM
DIA	1	Current TO 1000 PM	400 PM TO 900 PM
Arapahoe County	1	Current TO 1000 PM	400 PM TO 900 PM
the City of Aurora	1	Current TO 1000 PM	400 PM TO 900 PM
Arvada	1	Current TO 1000 PM	200 PM TO 900 PM
Wheat Ridge	1	Current TO 1000 PM	200 PM TO 900 PM
Lakewood	1	Current TO 1000 PM	200 PM TO 900 PM

County-specific Quantitative Precipitation Outlook	Precipitation Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	200 PM TO 1000 PM	0.1" (90%) to 0.4" (60%) to 1.0" (20%)	ISSUED
Arapahoe	200 PM TO 1000 PM	0.1" (90%) to 0.4" (60%) to 1.0" (20%)	ISSUED
Boulder	200 PM TO 1000 PM	0.1" (90%) to 0.4" (60%) to 1.0" (20%)	ISSUED
Broomfield	200 PM TO 1000 PM	0.1" (90%) to 0.4" (60%) to 1.0" (20%)	ISSUED
Denver	200 PM TO 1000 PM	0.1" (90%) to 0.4" (60%) to 1.0" (20%)	ISSUED
Douglas	200 PM TO 1000 PM	0.1" (90%) to 0.4" (65%) to 1.0" (20%)	ISSUED
Jefferson	200 PM TO 1000 PM	0.1" (90%) to 0.4" (65%) to 1.0" (20%)	ISSUED
Foothills above 6500ft
Boulder	100 PM TO 1000 PM	0.1" (100%) to 0.4" (75%) to 1.0" (25%)	ISSUED
Douglas	Current TO 1000 PM MON	0.1" (100%) to 0.4" (75%) to 1.0" (25%)	ISSUED
Jefferson	Current TO 1000 PM MON	0.1" (100%) to 0.4" (75%) to 1.0" (25%)	ISSUED

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.