Flash Flood Prediction Program

Message 2’s (NWS Flood/Flash Flood Watch) currently remains valid until midnight tonight but there is a good chance that the Watch will be rescinded early as the threat for heavy rainfall is lowering as we move into the evening and temperatures have cooled into the 60's to around 70.

There will still be a good chance for showers and weak to moderate thunderstorms but nothing like the intense thunderstorms that impacted portions of the District earlier today with heavy rainfall, large damaging hail and even isolated tornadoes over Douglas County. New storms are staging to the W over the foothills and will progress eastward but with a cooler air mass in place the strength of the storms will be weaker than earlier today, and it will not take as much rain to produce runoff as the ground is saturated and creeks and streams are still running high.

Best chances for additional rain showers and weak to moderate thunderstorms will be through about 9pm. If NWS cancels the Flood/Flash Flood Watch, Message 4’s (All Clear) will be issued.

STORM RAINFALL POTENTIAL AND DURATION: Rain showers and weak thunderstorms will produce a trace to 0.3” of rain. Moderate thunderstorms will have the potential to produce rainfall rates of 0.3-0.7” in 10-30 minutes.

WORST CASE SCENARIO: Should a strong thunderstorm be able to develop heavy rainfall of 0.5-1.5” in 10-30 minutes continues possible.

County	Message	Valid Times	Prime Time
Boulder County	2	1200 PM TO 1159 PM	1200 PM TO 1100 PM
Jefferson County	2	1200 PM TO 1159 PM	1200 PM TO 1100 PM
Broomfield County	2	1200 PM TO 1159 PM	1200 PM TO 1100 PM
Douglas County	2	1200 PM TO 1159 PM	1200 PM TO 1100 PM
Adams County	2	1200 PM TO 1159 PM	1200 PM TO 1100 PM
Denver County	2	1200 PM TO 1159 PM	1200 PM TO 1100 PM
DIA	2	1200 PM TO 1159 PM	1200 PM TO 1100 PM
Arapahoe County	2	1200 PM TO 1159 PM	1200 PM TO 1100 PM
the City of Aurora	2	1200 PM TO 1159 PM	1200 PM TO 1100 PM
Arvada	2	1200 PM TO 1159 PM	1200 PM TO 1100 PM
Wheat Ridge	2	1200 PM TO 1159 PM	1200 PM TO 1100 PM
Lakewood	2	1200 PM TO 1159 PM	1200 PM TO 1100 PM

County-specific Quantitative Precipitation Outlook	Precipitation Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	Current TO 1159 PM THU	0.1" (60%) to 0.3" (30%) to 0.7" (10%)	ISSUED
Arapahoe	Current TO 1159 PM THU	0.1" (60%) to 0.3" (30%) to 0.7" (10%)	ISSUED
Boulder	Current TO 1159 PM THU	0.1" (60%) to 0.3" (30%) to 0.7" (10%)	ISSUED
Broomfield	Current TO 1159 PM THU	0.1" (60%) to 0.3" (30%) to 0.7" (10%)	ISSUED
Denver	Current TO 1159 PM THU	0.1" (60%) to 0.3" (30%) to 0.7" (10%)	ISSUED
Douglas	Current TO 1159 PM THU	0.1" (60%) to 0.3" (30%) to 0.7" (10%)	ISSUED
Jefferson	Current TO 1159 PM THU	0.1" (60%) to 0.3" (30%) to 0.7" (10%)	ISSUED
Foothills above 6500ft
Boulder	Current TO 1159 PM THU	0.1" (80%) to 0.3" (50%) to 0.7" (20%)	ISSUED
Douglas	Current TO 1159 PM THU	0.1" (80%) to 0.3" (50%) to 0.7" (20%)	ISSUED
Jefferson	Current TO 1159 PM THU	0.1" (80%) to 0.3" (50%) to 0.7" (20%)	ISSUED

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.