Flash Flood Prediction Program

-	NW flow aloft and a passing upper level jet streak is helping to support stronger storms over portions of Weld County currently. As these storms track SSE into relatively drier air they are expected to weaken but if they maintain their strength brief moderate to heavy rainfall is possible.
-	Best chances for stronger thunderstorms today will be E of I-25 where moisture is a bit deeper. Thunderstorms will be fat moving from NNW to SSE at around 25mph. The fast storm motions will help to limit point rainfall amounts from a single storm. Strong thunderstorms may also produce large hail and gusty straight-line winds.
-	Shower and thunderstorm activity is expected to decrease by sunset but additional isolated showers and possibly a thunderstorm will remain possible 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 1.5" in 45-60 minutes.

A LOOK AHEAD: Temperatures will back off into the 80's for highs on Sunday as a cool front moves through. Thunderstorm activity is expected to increase and stronger storms will be capable of producing heavy rainfall, gusty winds and large hail.

Location	Prime Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	330 PM TO 830 PM	Trace (85%) to 0.3" (40%) to 0.8" (10%)	MOD
Arapahoe	330 PM TO 830 PM	Trace (85%) to 0.3" (40%) to 0.8" (10%)	MOD
Boulder	330 PM TO 830 PM	Trace (75%) to 0.3" (35%) to 0.8" (10%)	LOW
Broomfield	330 PM TO 830 PM	Trace (75%) to 0.3" (35%) to 0.8" (10%)	LOW
Denver	330 PM TO 830 PM	Trace (80%) to 0.3" (40%) to 0.8" (10%)	MOD
Douglas	330 PM TO 830 PM	Trace (65%) to 0.3" (30%) to 0.8" (10%)	LOW
Jefferson	330 PM TO 830 PM	Trace (65%) to 0.3" (30%) to 0.8" (10%)	LOW
Foothills above 6500ft
Boulder	Current TO 830 PM SAT	Trace (85%) to 0.3" (30%) to 0.8" (5%)	LOW
Douglas	Current TO 830 PM SAT	Trace (85%) to 0.3" (30%) to 0.8" (5%)	LOW
Jefferson	Current TO 830 PM SAT	Trace (85%) to 0.3" (30%) to 0.8" (5%)	LOW

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.