Flash Flood Prediction Program

Storms have currently developed over the higher elevations, around the Continental Divide, and will move into the District within the next hour or two.

Storm motions will be moving WNW to ESE at 10-20 mph, which could either limit or increase point rainfall amounts, depending on their speeds when they move off of the Foothills. Erratic outflows from storms could increase coverage and lower speeds, increasing point rainfall amounts for the District. The biggest threat will be this afternoon and very early evening will be a quick 0.50-0.80” in 10-30 minutes rather than any long lasting rainfall.

Storms will continue to impact the region over the next several hours with a few lingering showers in the early evening. Skies will gradually clear by sunset with temperatures dropping into the low 60s in the plains and mid to upper 50s in the foothills.

STORM RAINFALL POTENTIAL AND DURATION: Typical showers and thunderstorms today will produce 0.25”-0.50” total in 10-30 minutes. A moderate to strong thunderstorm will produce 0.50"-0.80" total in 10-30 minutes.

WORST CASE SCENARIO: A slow-moving, strong thunderstorm may be capable of producing up to 1.25” or more in 30 minutes or less.

County	Message	Valid Times	Prime Time
the City of Aurora	1	100 PM TO 800 PM	200 PM TO 700 PM
Arapahoe County	1	100 PM TO 800 PM	200 PM TO 700 PM
DIA	1	100 PM TO 800 PM	200 PM TO 700 PM
Denver County	1	100 PM TO 800 PM	200 PM TO 700 PM
Adams County	1	100 PM TO 800 PM	200 PM TO 700 PM
Douglas County	1	100 PM TO 800 PM	200 PM TO 700 PM
Broomfield County	1	100 PM TO 800 PM	200 PM TO 700 PM
Jefferson County	1	100 PM TO 800 PM	200 PM TO 700 PM
Boulder County	1	100 PM TO 800 PM	200 PM TO 700 PM
Arvada	1	100 PM TO 800 PM	200 PM TO 700 PM
Wheat Ridge	1	100 PM TO 800 PM	200 PM TO 700 PM
Lakewood	1	100 PM TO 800 PM	200 PM TO 700 PM

County-specific Quantitative Precipitation Outlook	Precipitation Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	100 PM TO 800 PM	0.25" (60%) to 0.5" (30%) to 0.8" (15%)	ISSUED
Arapahoe	100 PM TO 800 PM	0.25" (60%) to 0.5" (30%) to 0.8" (15%)	ISSUED
Boulder	100 PM TO 800 PM	0.25" (60%) to 0.5" (30%) to 0.8" (15%)	ISSUED
Broomfield	100 PM TO 800 PM	0.25" (60%) to 0.5" (30%) to 0.8" (15%)	ISSUED
Denver	100 PM TO 800 PM	0.25" (60%) to 0.5" (30%) to 0.8" (15%)	ISSUED
Douglas	100 PM TO 800 PM	0.25" (60%) to 0.5" (30%) to 0.8" (15%)	ISSUED
Jefferson	100 PM TO 800 PM	0.25" (60%) to 0.5" (30%) to 0.8" (15%)	ISSUED
Foothills above 6500ft
Boulder	100 PM TO 800 PM	0.25" (75%) to 0.5" (45%) to 0.8" (25%)	ISSUED
Douglas	100 PM TO 800 PM	0.25" (75%) to 0.5" (45%) to 0.8" (25%)	ISSUED
Jefferson	100 PM TO 800 PM	0.25" (75%) to 0.5" (45%) to 0.8" (25%)	ISSUED

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.