Flash Flood Prediction Program

Message 1’s will be allowed to expire at 11:59 pm as the threat of heavy rainfall has come to an end.

A few showers/isolated thunderstorms continue to impact portions of the District behind a gust front from the north. Storm motions have increased to 15-25mph from the W/SW to E/NE which will limit point rainfall amounts for any additional showers/isolated thunderstorms through the overnight. A chance for off and on showers will be possible through daybreak tomorrow, however these showers will likely be hit or miss with many areas ending up dry through tomorrow morning.

Overnight lows will drop into the low to mid 50’s on the plains with upper 40’s to around 50 along the foothills. Upper-level flow aloft shift more westerly tomorrow with breezy northerly winds with gusts up to 25mph in the afternoon. Another good chance for storms tomorrow afternoon, although the intensity of these storms will hinge on whether there is sufficient daytime heating.

STORM RAINFALL POTENTIAL AND DURATION: Typical showers or a weak thunderstorm will produce a trace to 0.25” total, in 10-30 minutes. A moderate to strong thunderstorm could produce 0.25-0.50” total, in 10-30 minutes.

WORST CASE SCENARIO: A slower moving strong thunderstorm or training of thunderstorm cells has the potential to produce 0.50-1.25” total, in under 60 minutes.

County	Message	Valid Times	Prime Time
the City of Aurora	1	Current TO 1159 PM	Current TO 1159 PM
Arapahoe County	1	Current TO 1159 PM	Current TO 1159 PM
DIA	1	Current TO 1159 PM	Current TO 1159 PM
Denver County	1	Current TO 1159 PM	Current TO 1159 PM
Adams County	1	Current TO 1159 PM	Current TO 1159 PM
Douglas County	1	Current TO 1159 PM	Current TO 1159 PM
Broomfield County	1	Current TO 1159 PM	Current TO 1159 PM
Jefferson County	1	Current TO 1159 PM	Current TO 1159 PM
Boulder County	1	Current TO 1159 PM	Current TO 1159 PM
Arvada	1	Current TO 1159 PM	Current TO 1159 PM
Wheat Ridge	1	Current TO 1159 PM	Current TO 1159 PM
Lakewood	1	Current TO 1159 PM	Current TO 1159 PM

County-specific Quantitative Precipitation Outlook	Precipitation Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	Current TO 600 AM FRI	Trace (60%) to 0.3" (30%) to 0.5" (15%)	ISSUED
Arapahoe	Current TO 600 AM FRI	Trace (60%) to 0.3" (30%) to 0.5" (15%)	ISSUED
Boulder	Current TO 600 AM FRI	Trace (50%) to 0.3" (25%) to 0.5" (10%)	ISSUED
Broomfield	Current TO 600 AM FRI	Trace (50%) to 0.3" (25%) to 0.5" (10%)	ISSUED
Denver	Current TO 600 AM FRI	Trace (50%) to 0.3" (25%) to 0.5" (10%)	ISSUED
Douglas	Current TO 600 AM FRI	Trace (50%) to 0.3" (25%) to 0.5" (10%)	ISSUED
Jefferson	Current TO 600 AM FRI	Trace (50%) to 0.3" (25%) to 0.5" (10%)	ISSUED
Foothills above 6500ft
Boulder	Current TO 600 AM FRI	Trace (50%) to 0.3" (25%) to 0.5" (10%)	ISSUED
Douglas	Current TO 600 AM FRI	Trace (60%) to 0.3" (30%) to 0.5" (15%)	ISSUED
Jefferson	Current TO 600 AM FRI	Trace (60%) to 0.3" (30%) to 0.5" (15%)	ISSUED

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.