Flash Flood Prediction Program

Message 1’s have been issued effective until 10pm as there is a threat of heavy rainfall this afternoon and evening. A few storms have formed along the foothills and will begin moving onto the plains over the next hour or so. A few rounds of showers/thunderstorms will be possible with the last round likely tapering off by 10pm. The largest threat for storms today will be a quick 0.5” in 10-15 minutes, with a low threat for any rainfall over an inch and hour as most storms move rather quickly between 15-25mph. These quick NW to SE storm motions should help limit point rainfall amounts, however, a stronger storm has the potential to produce a gust front resulting in additional, erratic storm development throughout the District. Skies will clear relatively fast behind the final round of showers with mild and dry conditions expected through the overnight.

STORM RAINFALL POTENTIAL AND DURATION: Typical showers will produce rainfall of 0.05" to 0.25” total in 10-30 minutes. Moderate to strong showers have the potential to produce rainfall of 0.25 to 0.75” total in 10-30 minutes.

WORST CASE SCENARIO: Strong stationery, or training of thunderstorms has the potential to produce 0.75” to 1.50” in under 60 minutes.

County	Message	Valid Times	Prime Time
Denver County	1	Current TO 1000 PM	Current TO 930 PM
Adams County	1	Current TO 1000 PM	Current TO 930 PM
Douglas County	1	Current TO 1000 PM	Current TO 930 PM
Lakewood	1	Current TO 1000 PM	Current TO 930 PM
Wheat Ridge	1	Current TO 1000 PM	Current TO 930 PM
Arvada	1	Current TO 1000 PM	Current TO 930 PM
the City of Aurora	1	Current TO 1000 PM	Current TO 930 PM
DIA	1	Current TO 1000 PM	Current TO 930 PM
Arapahoe County	1	Current TO 1000 PM	Current TO 930 PM
Broomfield County	1	Current TO 1000 PM	Current TO 930 PM
Jefferson County	1	Current TO 1000 PM	Current TO 930 PM
Boulder County	1	Current TO 1000 PM	Current TO 930 PM

County-specific Quantitative Precipitation Outlook	Precipitation Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	Current TO 1000 PM MON	0.05" (75%) to 0.25" (50%) to 0.75" (25%)	ISSUED
Arapahoe	Current TO 1000 PM MON	0.05" (75%) to 0.25" (50%) to 0.75" (25%)	ISSUED
Boulder	Current TO 1000 PM MON	0.05" (75%) to 0.25" (50%) to 0.75" (25%)	ISSUED
Broomfield	Current TO 1000 PM MON	0.05" (75%) to 0.25" (50%) to 0.75" (25%)	ISSUED
Denver	Current TO 1000 PM MON	0.05" (75%) to 0.25" (50%) to 0.75" (25%)	ISSUED
Douglas	Current TO 1000 PM MON	0.05" (75%) to 0.25" (50%) to 0.75" (25%)	ISSUED
Jefferson	Current TO 1000 PM MON	0.05" (75%) to 0.25" (50%) to 0.75" (25%)	ISSUED
Foothills above 6500ft
Boulder	Current TO 1000 PM MON	0.05" (80%) to 0.25" (60%) to 0.75" (30%)	ISSUED
Douglas	Current TO 1000 PM MON	0.05" (80%) to 0.25" (60%) to 0.75" (30%)	ISSUED
Jefferson	Current TO 1000 PM MON	0.05" (80%) to 0.25" (60%) to 0.75" (30%)	ISSUED

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.