Flash Flood Prediction Program

A gust front is currently approaching the District from the northeast and pulsing up thunderstorms in its wake. This gust front will move all the way through the District and push into the foothills allowing the chance of thunderstorms within the District during the evening hours. Storms that do develop will contain moderate to brief heavy rainfall.

Storm motions will be moving NNW to SSE at 20-25 mph, which should limit point rainfall amounts. Stronger storms will produce outflow boundaries and could cause erratic movement, lower speeds, increasing point rainfall amounts for the District. The biggest threat will be this evening will be a quick 0.50-1.00” total in 10-30 minutes rather than any long lasting rainfall.

Additional showers could impact the region overnight, keeping lows around 60 for the plains and around 50 for the foothills be daybreak tomorrow.

STORM RAINFALL POTENTIAL AND DURATION: Typical showers thunderstorms today will produce 0.25"-0.50” in 10-30 minutes. Stronger/slower moving storms will produce up to 1.00" in 10-30 minutes.

WORST CASE SCENARIO: A strong/stationary thunderstorm, or training of thunderstorms, may be capable of producing up to 1.50” or more in 30 minutes or less.

County	Message	Valid Times	Prime Time
Arvada	1	Current TO 1100 PM	700 PM TO 1000 PM
the City of Aurora	1	Current TO 1100 PM	700 PM TO 1000 PM
Arapahoe County	1	Current TO 1100 PM	700 PM TO 1000 PM
DIA	1	Current TO 1100 PM	700 PM TO 1000 PM
Denver County	1	Current TO 1100 PM	700 PM TO 1000 PM
Douglas County	1	Current TO 1100 PM	700 PM TO 1000 PM
Adams County	1	Current TO 1100 PM	700 PM TO 1000 PM
Broomfield County	1	Current TO 1100 PM	700 PM TO 1000 PM
Jefferson County	1	Current TO 1100 PM	700 PM TO 1000 PM
Boulder County	1	Current TO 1100 PM	700 PM TO 1000 PM
Wheat Ridge	1	Current TO 1100 PM	700 PM TO 1000 PM
Lakewood	1	Current TO 1100 PM	700 PM TO 1000 PM

County-specific Quantitative Precipitation Outlook	Precipitation Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	Current TO 1100 PM SAT	0.3" (60%) to 0.5" (40%) to 1" (20%)	ISSUED
Arapahoe	Current TO 1100 PM SAT	0.3" (60%) to 0.5" (40%) to 1" (20%)	ISSUED
Boulder	Current TO 1100 PM SAT	0.3" (60%) to 0.5" (40%) to 1" (20%)	ISSUED
Broomfield	Current TO 1100 PM SAT	0.3" (60%) to 0.5" (40%) to 1" (20%)	ISSUED
Denver	Current TO 1100 PM SAT	0.3" (60%) to 0.5" (40%) to 1" (20%)	ISSUED
Douglas	Current TO 1100 PM SAT	0.3" (60%) to 0.5" (40%) to 1" (20%)	ISSUED
Jefferson	Current TO 1100 PM SAT	0.3" (60%) to 0.5" (40%) to 1" (20%)	ISSUED
Foothills above 6500ft
Boulder	Current TO 1100 PM SAT	0.3" (60%) to 0.5" (40%) to 1" (20%)	ISSUED
Douglas	Current TO 1100 PM SAT	0.3" (60%) to 0.5" (40%) to 1" (20%)	ISSUED
Jefferson	Current TO 1100 PM SAT	0.3" (60%) to 0.5" (40%) to 1" (20%)	ISSUED

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.