Flash Flood Prediction Program

-	Message 1's have been issued for the entire District and will be valid through 9pm this evening.
-	A vigorous upper level disturbance will move through the region this afternoon through early evening likely resulting in 1-2 rounds of moderate to strong thunderstorms with the potential for heavy rainfall. Strong thunderstorms may also produce severe weather in the form of gusty straight-line winds in excess of 50mph and large hail.
-	Best chances for thunderstorms will be from 3-9pm. Storms will be relatively fast moving from SW to NE at around 20mph which will help to lower point rainfall amounts from a single storm. A surface wind convergence line is currently trying to develop over the District and may result in storms anchoring briefly along the line or moving more slowly which could result in extended periods of heavy rain.

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

WORST CASE SCENARIO: A slower moving thunderstorm or a briefly anchored thunderstorm may result in up to 2.2" of rainfall in 60 minutes or less.

County	Message	Valid Times	Prime Time
Boulder County	1	Current TO 900 PM	300 PM TO 800 PM
Jefferson County	1	Current TO 900 PM	300 PM TO 800 PM
Broomfield County	1	Current TO 900 PM	300 PM TO 800 PM
Douglas County	1	Current TO 900 PM	300 PM TO 800 PM
Adams County	1	Current TO 900 PM	300 PM TO 800 PM
Denver County	1	Current TO 900 PM	300 PM TO 800 PM
DIA	1	Current TO 900 PM	300 PM TO 800 PM
Arapahoe County	1	Current TO 900 PM	300 PM TO 800 PM
the City of Aurora	1	Current TO 900 PM	300 PM TO 800 PM
Arvada	1	Current TO 900 PM	300 PM TO 800 PM
Wheat Ridge	1	Current TO 900 PM	300 PM TO 800 PM
Lakewood	1	Current 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" (95%) to 0.4" (65%) to 1.2" (30%)	ISSUED
Arapahoe	300 PM TO 900 PM	0.1" (95%) to 0.4" (65%) to 1.2" (30%)	ISSUED
Broomfield	300 PM TO 900 PM	0.1" (95%) to 0.4" (65%) to 1.2" (30%)	ISSUED
Denver	300 PM TO 900 PM	0.1" (95%) to 0.4" (65%) to 1.2" (30%)	ISSUED
Boulder	230 PM TO 900 PM	0.1" (95%) to 0.4" (65%) to 1.2" (25%)	ISSUED
Douglas	230 PM TO 900 PM	0.1" (95%) to 0.4" (65%) to 1.2" (25%)	ISSUED
Jefferson	230 PM TO 900 PM	0.1" (95%) to 0.4" (65%) to 1.2" (25%)	ISSUED
Foothills above 6500ft
Boulder	Current TO 800 PM SUN	0.1" (95%) to 0.4" (60%) to 1.2" (20%)	ISSUED
Douglas	Current TO 800 PM SUN	0.1" (95%) to 0.4" (60%) to 1.2" (20%)	ISSUED
Jefferson	Current TO 800 PM SUN	0.1" (95%) to 0.4" (60%) to 1.2" (20%)	ISSUED

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.