Flash Flood Prediction Program

Message 1’s have been issued for the entire District effective until 9pm.

A weak gust front collision east has initiated storms at this time, specifically around the Thornton/Brighton area. This storm has rapidly developed and will have the potential for moderate to heavy rainfall. This storm has the potential to produce additional gust fronts, similar to yesterday which could trigger additional storms, favoring eastern portions of the District through the evening.

The largest storm threat will be a quick 0.5” in 10 minutes, however, a stronger storm that stalls out for an extended period should have no issue dumping over 1” per rainfall in 10-30 minutes as dew points remain elevated in some spots. Storms will taper off by sunset with skies gradually clearing through the overnight.

Overnight lows will drop into the low 60’s along the plains with mid to upper 50’s along the foothills.

STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers, weak thunderstorms will produce a 0.10-0.50” total in 10-30 minute. A moderate to strong thunderstorm will produce 0.50-1.20” total in 10-30 minutes.

WORST CASE SCENARIO: A strong, anchored thunderstorm will have the potential to produce 2.00” in 45-60 minutes.

County	Message	Valid Times	Prime Time
Arvada	1	Current TO 900 PM	Current TO 830 PM
Wheat Ridge	1	Current TO 900 PM	Current TO 830 PM
the City of Aurora	1	Current TO 900 PM	Current TO 830 PM
DIA	1	Current TO 900 PM	Current TO 830 PM
Arapahoe County	1	Current TO 900 PM	Current TO 830 PM
Denver County	1	Current TO 900 PM	Current TO 830 PM
Adams County	1	Current TO 900 PM	Current TO 830 PM
Douglas County	1	Current TO 900 PM	Current TO 830 PM
Broomfield County	1	Current TO 900 PM	Current TO 830 PM
Jefferson County	1	Current TO 900 PM	Current TO 830 PM
Boulder County	1	Current TO 900 PM	Current TO 830 PM
Lakewood	1	Current TO 900 PM	Current TO 830 PM

County-specific Quantitative Precipitation Outlook	Precipitation Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	Current TO 900 PM SUN	0.1" (60%) to 0.5" (30%) to 1.2" (15%)	ISSUED
Arapahoe	Current TO 900 PM SUN	0.1" (60%) to 0.5" (30%) to 1.2" (15%)	ISSUED
Boulder	Current TO 900 PM SUN	0.1" (60%) to 0.5" (30%) to 1.2" (15%)	ISSUED
Broomfield	Current TO 900 PM SUN	0.1" (60%) to 0.5" (30%) to 1.2" (15%)	ISSUED
Denver	Current TO 900 PM SUN	0.1" (60%) to 0.5" (30%) to 1.2" (15%)	ISSUED
Douglas	Current TO 900 PM SUN	0.1" (60%) to 0.5" (30%) to 1.2" (15%)	ISSUED
Jefferson	Current TO 900 PM SUN	0.1" (60%) to 0.5" (30%) to 1.2" (15%)	ISSUED
Foothills above 6500ft
Boulder	Current TO 900 PM SUN	0.1" (50%) to 0.5" (25%) to 1.2" (10%)	ISSUED
Douglas	Current TO 900 PM SUN	0.1" (50%) to 0.5" (25%) to 1.2" (10%)	ISSUED
Jefferson	Current TO 900 PM SUN	0.1" (50%) to 0.5" (25%) to 1.2" (10%)	ISSUED

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.