Time: 816 AM Sat September 19, 2020 Forecaster: Brad Simmons

Heavy Precipitation Outlook
Flash Flood Prediction Program

CONTINUED UNSEASONABLY WARM WITH POSSIBLY A HIGH-BASED SHOWER OR WEAK THUNDERSTORM LATE
-An upper level trough of low pressure is on the approach today resulting in a slight chance for a high-based shower or weak thunderstorm late this afternoon and evening. Surface moisture is lacking which will keep most areas on the dry side with any showers and weak thunderstorms mainly producing virga and gusty winds with possibly a few sprinkles. Best chances for storm activity today will be between 4pm and midnight.
-Temperatures will continue to run above normal with highs in the 80's over the plains with 70's in the Front Range foothills. Some improvement in the smoke/haze is expected today but visibility will still be reduced with skies being partly cloudy for the majority of the day and mostly cloudy late.
-After midnight completely dry conditions are expected for the remainder of the overnight period with temperatures bottoming out in the 50's over the plains and 40's in the foothills.
STORM RAINFALL POTENTIAL AND DURATION: Isolated high-based rain showers and possibly a weak thunderstorm will have the potential to produce a trace to 0.1". Supplemental QPF is available at https://qpf.udfcd.org

A LOOK AHEAD: A few degrees cooler on Sunday with continued improvement in air quality as the smoke/haze is expected to decrease. Dry conditions are expected over the plains with possibly a very isolated shower or weak thunderstorm in the foothills.

Location Prime Time 30-Minute Rainfall
and % Probability
Message
Potential
Plains      
Adams 400 PM TO 1159 PM
Trace (10%) to 0.1" (5%) NONE
Arapahoe 400 PM TO 1159 PM
Trace (10%) to 0.1" (5%) NONE
Boulder 400 PM TO 1159 PM
Trace (10%) to 0.1" (5%) NONE
Broomfield 400 PM TO 1159 PM
Trace (10%) to 0.1" (5%) NONE
Denver 400 PM TO 1159 PM
Trace (10%) to 0.1" (5%) NONE
Douglas 400 PM TO 1159 PM
Trace (10%) to 0.1" (5%) NONE
Jefferson 400 PM TO 1159 PM
Trace (10%) to 0.1" (5%) NONE
Foothills above 6500ft      
Boulder 300 PM TO 1159 PM
Trace (20%) to 0.1" (10%) NONE
Douglas 300 PM TO 1159 PM
Trace (20%) to 0.1" (10%) NONE
Jefferson 300 PM TO 1159 PM
Trace (20%) to 0.1" (10%) NONE
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.