Flash Flood Prediction Program

Message 1’s have been extended as the threat of heavy rainfall remains over the District.

A line of storms is currently moving into the District from the southwest. A gust front from the northeast is also moving into the District and these will converge over the District over the next few hours. Behind this gust front, dew points are very elevated, around 60 degrees, resulting in a good chance for efficient rainfall producing storms.

Currently storm motions are fairly brisk out of the southwest between 15-25mph, although storm movements may become erratic once the gust front from the northeast moves in. The strongest storms are currently in Douglas County and are expected to move northeastward and into Denver and Arapahoe Counties. Additional storms could initiate in north and northwestern portions of the District, however the best chance for heavy rainfall will likely be for south and southeastern portions of the District through the rest of the evening. Stronger storms should diminish by 10pm with light to moderate storms through 11pm.

STORM RAINFALL POTENTIAL AND DURATION: Typical showers/thunderstorms will produce a 0.05-0.25” total in 10 to 30 minutes. A moderate thunderstorm will produce 0.25” to 0.75” total in 10 to 30 minutes. A strong thunderstorm will produce 0.75” to 1.25” total in 10 to 30 minutes.

WORST CASE SCENARIO: An anchored strong thunderstorm or training of thunderstorm cells has the potential to produce up to 2.5” in under 60 minutes.

County	Message	Valid Times	Prime Time
Lakewood	1	Current TO 1100 PM	Current TO 1030 PM
Wheat Ridge	1	Current TO 1100 PM	Current TO 1030 PM
Arvada	1	Current TO 1100 PM	Current TO 1030 PM
the City of Aurora	1	Current TO 1100 PM	Current TO 1030 PM
Arapahoe County	1	Current TO 1100 PM	Current TO 1030 PM
DIA	1	Current TO 1100 PM	Current TO 1030 PM
Denver County	1	Current TO 1100 PM	Current TO 1030 PM
Adams County	1	Current TO 1100 PM	Current TO 1030 PM
Douglas County	1	Current TO 1100 PM	Current TO 1030 PM
Broomfield County	1	Current TO 1100 PM	Current TO 1030 PM
Jefferson County	1	Current TO 1100 PM	Current TO 1030 PM
Boulder County	1	Current TO 1100 PM	Current TO 1030 PM

County-specific Quantitative Precipitation Outlook	Precipitation Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	Current TO 1100 PM WED	0.25" (75%) to 0.75" (35%) to 1.25" (15%)	ISSUED
Arapahoe	Current TO 1100 PM WED	0.25" (80%) to 0.75" (40%) to 1.25" (20%)	ISSUED
Boulder	Current TO 1100 PM WED	0.25" (60%) to 0.75" (30%) to 1.25" (15%)	ISSUED
Broomfield	Current TO 1100 PM WED	0.25" (60%) to 0.75" (30%) to 1.25" (15%)	ISSUED
Denver	Current TO 1100 PM WED	0.25" (80%) to 0.75" (40%) to 1.25" (20%)	ISSUED
Douglas	Current TO 1100 PM WED	0.25" (80%) to 0.75" (40%) to 1.25" (20%)	ISSUED
Jefferson	Current TO 1100 PM WED	0.25" (60%) to 0.75" (30%) to 1.25" (15%)	ISSUED
Foothills above 6500ft
Boulder	Current TO 1100 PM WED	0.25" (50%) to 0.75" (25%) to 1.25" (10%)	ISSUED
Douglas	Current TO 1100 PM WED	0.25" (50%) to 0.75" (25%) to 1.25" (10%)	ISSUED
Jefferson	Current TO 1100 PM WED	0.25" (50%) to 0.75" (25%) to 1.25" (10%)	ISSUED

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.