Flash Flood Prediction Program

Message 2’s will continue valid as the threat of heavy rainfall remains at this time.

Widespread heavy, long-lasting rainfall impacted the District today with storms moving well onto the eastern plains at this time. The brunt of the storm action has tapered off, however, a few light lingering showers persist over the District currently and will continue over the next couple of hours. Another surge of showers/thunderstorms will be possible this evening, with an abundance of available moisture, and good upper-level support still in play, even moderate showers will bring heavy rainfall resulting in a chance for heavy rainfall into this evening. The best chance for additional storm activity will be from 6-10pm this evening.

Currently temperatures are in the low to mid 50’s across the District, which will help limit the storm strength through midnight. After midnight, a few lingering light showers will be possible, with a slight chance for a few isolated showers through tomorrow morning. Overnight lows will drop to around 50 degrees on the plains with mid 40’s along the foothills.

STORM RAINFALL POTENTIAL AND DURATION: Typical thunderstorms have the potential to produce rainfall between a 0.1-0.4” total, in 10-30 minutes. Moderate to strong thunderstorms have the potential to produce moderate to heavy rainfall of 0.4” to 1.0" total, in 10-30 minutes.

WORST CASE SCENARIO: Trainign or slow-moving thunderstorms have the potential to produce
up to 1.8” total in 45-60 minutes.

County	Message	Valid Times	Prime Time
Boulder County	2	Current TO 1159 PM	Current TO 800 PM
Jefferson County	2	Current TO 1159 PM	Current TO 800 PM
Broomfield County	2	Current TO 1159 PM	Current TO 800 PM
Douglas County	2	Current TO 1159 PM	Current TO 800 PM
Adams County	2	Current TO 1159 PM	Current TO 800 PM
Denver County	2	Current TO 1159 PM	Current TO 800 PM
DIA	2	Current TO 1159 PM	Current TO 800 PM
Arapahoe County	2	Current TO 1159 PM	Current TO 800 PM
the City of Aurora	2	Current TO 1159 PM	Current TO 800 PM
Arvada	2	Current TO 1159 PM	Current TO 800 PM
Wheat Ridge	2	Current TO 1159 PM	Current TO 800 PM
Lakewood	2	Current TO 1159 PM	Current TO 800 PM

County-specific Quantitative Precipitation Outlook	Precipitation Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	Current TO 1159 PM MON	0.1" (50%) to 0.4" (25%) to 1" (15%)	ISSUED
Arapahoe	Current TO 1159 PM MON	0.1" (50%) to 0.4" (25%) to 1" (15%)	ISSUED
Boulder	Current TO 1159 PM MON	0.1" (50%) to 0.4" (25%) to 1" (15%)	ISSUED
Broomfield	Current TO 1159 PM MON	0.1" (50%) to 0.4" (25%) to 1" (15%)	ISSUED
Denver	Current TO 1159 PM MON	0.1" (50%) to 0.4" (25%) to 1" (15%)	ISSUED
Douglas	Current TO 1159 PM MON	0.1" (60%) to 0.4" (30%) to 1" (20%)	ISSUED
Jefferson	Current TO 1159 PM MON	0.1" (60%) to 0.4" (30%) to 1" (20%)	ISSUED
Foothills above 6500ft
Boulder	Current TO 1159 PM MON	0.1" (75%) to 0.4" (50%) to 1" (25%)	ISSUED
Douglas	Current TO 1159 PM MON	0.1" (75%) to 0.4" (50%) to 1" (25%)	ISSUED
Jefferson	Current TO 1159 PM MON	0.1" (75%) to 0.4" (50%) to 1" (25%)	ISSUED

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.