Flash Flood Prediction Program

Message 1’s have been issued for the entire District and will be valid until 8:00pm this evening.

Once again storms have initiated along the higher terrain and are slowly moving onto the plains at this time. Temperatures have remained in the mid to upper 60’s which should help suppress stronger storm development this afternoon. Dew points are currently in the mid to upper 40’s resulting in even moderate thunderstorms to produce heavy rainfall. The best chance for showers and thunderstorms will be from NOW until 8pm with lingering rain showers possible through midnight.

Storm motions today will continue from the S/SE to N/NE for the most part, with additional storms likely forming along outflow boundaries. These outflow storms will likely have the highest chance of bringing localized heavy rainfall as the storm movements will be non-existent at times. There could be multiple rounds of storms today, however the initial round should have highest chance for impactful rain showers, with additional rounds likely becoming much weaker into the evening hours.

STORM RAINFALL POTENTIAL AND DURATION: Weak to moderate thunderstorms will produce 0.1-0.3” of rain in 10-30 minutes. Strong thunderstorms will have the potential to produce rainfall rates of 0.3-0.7” in 10-30 minutes.

WORST CASE SCENARIO: A nearly stationary strong thunderstorm may result in up to 1.4” of rain in 45-75 minutes.

County	Message	Valid Times	Prime Time
Boulder County	1	Current TO 800 PM	Current TO 700 PM
Jefferson County	1	Current TO 800 PM	Current TO 700 PM
Broomfield County	1	Current TO 800 PM	Current TO 700 PM
Douglas County	1	Current TO 800 PM	Current TO 700 PM
Adams County	1	Current TO 800 PM	Current TO 700 PM
Denver County	1	Current TO 800 PM	Current TO 700 PM
DIA	1	Current TO 800 PM	Current TO 700 PM
Arapahoe County	1	Current TO 800 PM	Current TO 700 PM
the City of Aurora	1	Current TO 800 PM	Current TO 700 PM
Arvada	1	Current TO 800 PM	Current TO 700 PM
Wheat Ridge	1	Current TO 800 PM	Current TO 700 PM
Lakewood	1	Current TO 800 PM	Current TO 700 PM

County-specific Quantitative Precipitation Outlook	Precipitation Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	Current TO 800 PM FRI	0.1" (80%) to 0.3" (40%) to 0.7" (20%)	ISSUED
Arapahoe	Current TO 800 PM FRI	0.1" (80%) to 0.3" (40%) to 0.7" (20%)	ISSUED
Boulder	Current TO 800 PM FRI	0.1" (80%) to 0.3" (40%) to 0.7" (20%)	ISSUED
Broomfield	Current TO 800 PM FRI	0.1" (80%) to 0.3" (40%) to 0.7" (20%)	ISSUED
Denver	Current TO 800 PM FRI	0.1" (80%) to 0.3" (40%) to 0.7" (20%)	ISSUED
Douglas	Current TO 800 PM FRI	0.1" (80%) to 0.3" (40%) to 0.7" (20%)	ISSUED
Jefferson	Current TO 800 PM FRI	0.1" (80%) to 0.3" (40%) to 0.7" (20%)	ISSUED
Foothills above 6500ft
Boulder	Current TO 800 PM FRI	0.1" (80%) to 0.3" (40%) to 0.7" (20%)	ISSUED
Douglas	Current TO 800 PM FRI	0.1" (80%) to 0.3" (40%) to 0.7" (20%)	ISSUED
Jefferson	Current TO 800 PM FRI	0.1" (80%) to 0.3" (40%) to 0.7" (20%)	ISSUED

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.