Flash Flood Prediction Program

-	High-pressure has finally broken down over the region as a cold front moves through resulting in more seasonable, cooler temperatures today in the low 80's for the plains with low 70's along the foothills. An increase in moisture at the surface today with dew points projected in the mid to upper 40's will bring a good chance for widespread rain showers/thunderstorms across the District this afternoon and evening.
-	Thunderstorms will first develop over the mountains and foothills by 12-2pm, moving onto the I-25 corridor between 2-4pm. Storms will be relatively fast moving from W/NW to E/SE at 10-20mph helping to limit point rainfall amounts from a single storm but brief heavy rainfall will be possible from stronger storms. Large thunderstorms formed along an outflow boundary or training of thunderstorm cells will have the greatest threat for heavy rainfall favoring areas south of I-70 at this time.
-	Storm activity will begin to decrease after sunset, although a few lingering showers or a weak thunderstorm will be possible through 10pm before tapering off completely through the overnight.

STORM RAINFALL POTENTIAL AND DURATION: Rain showers and weak to moderate thunderstorms will produce a trace to 0.3". Moderate to strong thunderstorms will have the potential to produce 0.3-0.8" in 10-30 mintues. Supplemental QPF is available at https://qpf.udfcd.org

WORST CASE SCENARIO: A large, slower moving thunderstorm or training of thunderstorm cells may produce rainfall amounts of up to 1.6" in 45-60 minutes.

A LOOK AHEAD: Similar conditions in place for Saturday with high temperatures remaining in the low to mid 80's across the District. Another good chance for afternoon and evening rain showers/thunderstorms with the potential for heavy rainfall. Seasonable temperatures continue into Sunday as moisture starts to decrease over the region resulting in only a slight chance for rain showers/thunderstorms Sunday afternoon and early evening.

Location	Prime Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	200 PM TO 900 PM	Trace (60%) to 0.3" (30%) to 0.8" (10%)	LOW
Arapahoe	200 PM TO 900 PM	Trace (60%) to 0.3" (40%) to 0.8" (20%)	MOD
Boulder	200 PM TO 900 PM	Trace (60%) to 0.3" (30%) to 0.8" (10%)	LOW
Broomfield	200 PM TO 900 PM	Trace (60%) to 0.3" (30%) to 0.8" (10%)	LOW
Denver	200 PM TO 900 PM	Trace (60%) to 0.3" (30%) to 0.8" (10%)	LOW
Douglas	200 PM TO 900 PM	Trace (60%) to 0.3" (40%) to 0.8" (20%)	MOD
Jefferson	200 PM TO 900 PM	Trace (60%) to 0.3" (30%) to 0.8" (10%)	LOW
Foothills above 6500ft
Boulder	200 PM TO 900 PM	Trace (60%) to 0.3" (30%) to 0.8" (10%)	LOW
Douglas	200 PM TO 900 PM	Trace (60%) to 0.3" (40%) to 0.8" (20%)	MOD
Jefferson	200 PM TO 900 PM	Trace (60%) to 0.3" (30%) to 0.8" (10%)	LOW

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.