Time: 738 AM Tue August 18, 2020 Forecaster: Justin Brooks

Heavy Precipitation Outlook
Flash Flood Prediction Program

HOT, HAZY AND GENERALLY DRY WITH A VERY SLIGHT CHANCE FOR A LATE AFTERNOON/EARLY EVENING HIGH-BASED ISOLATED RAIN SHOWER/THUNDERSTORM
-High-pressure continues to churn towards our SW resulting in continued N/NW upper-level flow today which will keep temperatures above average in the mid to upper 90's across the plains with mid to upper 80's along the foothills.
-A very weak disturbance will move in from the NW late this afternoon which could trigger some weak storm development over the District, however, isolated thunderstorms today will be high-based with minimal, if any precipitation reaching the ground. Best chance for storm development today will be from 3-8pm. 90 degree temperatures with upper 30's to low 40's dew points suggest that any storms that do develop can produce very gusty winds with gusts up to 60mph along with dry lightning.
-Skies will gradually clear after sunset as low temperatures drop into the 60's overnight.
STORM RAINFALL POTENTIAL AND DURATION: Very isolated rain showers and weak thunderstorms will have the potential to produce a trace to 0.1" of rain. Supplemental QPF is available at https://qpf.udfcd.org

WORST CASE SCENARIO: A moderate thunderstorm, if able to develop, will have the potential to produce 0.1-0.2" of rain in 10-30 minutes.

A LOOK AHEAD: Slightly cooler Wednesday as high temperatures drop into the upper 80's to low 90's across the plains. Hazy skies will continue as fires still burn up in the high country. A very slight chance for high-based storms during the afternoon and early evening. An uptick in moisture Thursday which will provide a better chance for rain showers and isolated thunderstorms. Conditions once again start to dry out heading into the weekend with a slight chance for scattered rain showers/isolated thunderstorms Friday and Saturday.

Location Prime Time 30-Minute Rainfall
and % Probability
Message
Potential
Plains      
Adams 300 PM TO 800 PM
Trace (20%) to 0.1" (10%) to 0.2" (5%) NONE
Arapahoe 300 PM TO 800 PM
Trace (20%) to 0.1" (10%) to 0.2" (5%) NONE
Boulder 300 PM TO 800 PM
Trace (20%) to 0.1" (10%) to 0.2" (5%) NONE
Broomfield 300 PM TO 800 PM
Trace (20%) to 0.1" (10%) to 0.2" (5%) NONE
Denver 300 PM TO 800 PM
Trace (20%) to 0.1" (10%) to 0.2" (5%) NONE
Douglas 300 PM TO 800 PM
Trace (20%) to 0.1" (10%) to 0.2" (5%) NONE
Jefferson 300 PM TO 800 PM
Trace (20%) to 0.1" (10%) to 0.2" (5%) NONE
Foothills above 6500ft      
Boulder 300 PM TO 800 PM
Trace (20%) to 0.1" (10%) to 0.2" (5%) NONE
Douglas 300 PM TO 800 PM
Trace (20%) to 0.1" (10%) to 0.2" (5%) NONE
Jefferson 300 PM TO 800 PM
Trace (20%) to 0.1" (10%) to 0.2" (5%) NONE
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.