Flash Flood Prediction Program

Message 1’s have been issued for the entire District effective until 10pm.

Storms have initiated along the higher terrain this morning and are slowly moving eastward as the follow the upper-level disturbance. As these storms progress eastward, some erratic storm motions could develop resulting in pockets of heavy rainfall leading to localized flooding. The biggest threat today will be a quick 0.5” in 10 minutes, rather than any long-lasting rainfall, however, some training of rain showers cannot be completely ruled out, also increasing the threat for localized flooding.

The best chance for showers and thunderstorms will be from now through 10pm this evening with a couple of rounds of storms possible. Models suggest the possibility of a late eve/overnight round of showers/isolated thunderstorms, however the threat for heavy rainfall is minimal at this time due to the timing of the storms. If these storms look to increase through the late evening/overnight, an extension of Message 1’s may be needed.

STORM RAINFALL POTENTIAL AND DURATION: Typical thunderstorms have the potential to produce moderate to heavy rainfall of 0.1-0.3" total, in 10-30 minutes. Strong thunderstorms have the potential to produce moderate to heavy rainfall of 0.3-0.8" total, in 10-30 minutes.

WORST CASE SCENARIO: Stationary or training of slow-moving thunderstorms have the potential to produce
up to 1.6” total, in 45-60 minutes.

County	Message	Valid Times	Prime Time
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
Arapahoe County	1	Current TO 1000 PM	Current TO 930 PM
DIA	1	Current TO 1000 PM	Current TO 930 PM
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
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 THU	0.1" (75%) to 0.3" (50%) to 0.8" (20%)	ISSUED
Arapahoe	Current TO 1000 PM THU	0.1" (75%) to 0.3" (50%) to 0.8" (20%)	ISSUED
Boulder	Current TO 1000 PM THU	0.1" (75%) to 0.3" (50%) to 0.8" (20%)	ISSUED
Broomfield	Current TO 1000 PM THU	0.1" (75%) to 0.3" (50%) to 0.8" (20%)	ISSUED
Denver	Current TO 1000 PM THU	0.1" (75%) to 0.3" (50%) to 0.8" (20%)	ISSUED
Douglas	Current TO 1000 PM THU	0.1" (75%) to 0.3" (50%) to 0.8" (20%)	ISSUED
Jefferson	Current TO 1000 PM THU	0.1" (75%) to 0.3" (50%) to 0.8" (20%)	ISSUED
Foothills above 6500ft
Boulder	Current TO 1000 PM THU	0.1" (90%) to 0.3" (60%) to 0.8" (30%)	ISSUED
Douglas	Current TO 1000 PM THU	0.1" (90%) to 0.3" (60%) to 0.8" (30%)	ISSUED
Jefferson	Current TO 1000 PM THU	0.1" (90%) to 0.3" (60%) to 0.8" (30%)	ISSUED

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.