Time: 1001 AM Thu June 20, 2019 Forecaster: Justin Brooks

Heavy Precipitation Outlook
Flash Flood Prediction Program

WARM TODAY WITH A CHANCE OF AN ISOLATED HIGH BASED SHOWER/THUNDERSTORM
-Warm temperatures continue today before high-pressure starts to break down this afternoon as a short wave moves over the region this afternoon resulting in a chance for showers/isolated thunderstorms this afternoon and early evening. Mostly sunny skies today will bring temperatures into the upper 80's over the plains, with upper 70's for the foothills.
-Relatively wide temperature/dew point spreads this afternoon suggests high based storms this afternoon, bringing gusty winds and light showers off the foothills with storm intensities increasing east of I-25 where better surface moisture will be present allowing for moderate showers favoring the eastern portion of the District with the threat for heavy rain remaining low.
-Today's showers and storms will track from west to east at around 15-20mph, with the best chance for a storm over the District occurring between 2pm-6pm.
STORM RAINFALL POTENTIAL AND DURATION: Typical showers and thunderstorms will produce rainfall amounts between Trace-0.20" in 10-30 minutes. A slower moving, or moderate storm will produce 0.20-0.50" in 10-30 minutes.

WORST CASE SCENARIO: Surface moisture remains higher than expected, allowing a strong thunderstorm to produce rainfall up to 0.80" in 10-30 minutes.

A LOOK AHEAD: A low-pressure system will move into the region Friday bringing a better chance for rain showers/isolated thunderstorms as well as a drop in temperatures this weekend into the upper 60's to low 70's with a very good chance for rain through Sunday.

Location Prime Time 30-Minute Rainfall
and % Probability
Message
Potential
Plains      
Adams 200 PM TO 600 PM
Trace (80%) to 0.2" (40%) to 0.5" (10%) LOW
Arapahoe 200 PM TO 600 PM
Trace (80%) to 0.2" (40%) to 0.5" (10%) LOW
Boulder 200 PM TO 600 PM
Trace (70%) to 0.2" (30%) to 0.5" (10%) LOW
Broomfield 200 PM TO 600 PM
Trace (70%) to 0.2" (30%) to 0.5" (10%) LOW
Denver 200 PM TO 600 PM
Trace (70%) to 0.2" (30%) to 0.5" (10%) LOW
Douglas 200 PM TO 600 PM
Trace (70%) to 0.2" (30%) to 0.5" (10%) LOW
Jefferson 200 PM TO 600 PM
Trace (70%) to 0.2" (30%) to 0.5" (10%) LOW
Foothills above 6500ft      
Boulder 200 PM TO 600 PM
Trace (70%) to 0.2" (30%) to 0.5" (10%) LOW
Douglas 200 PM TO 600 PM
Trace (70%) to 0.2" (30%) to 0.5" (10%) LOW
Jefferson 200 PM TO 600 PM
Trace (70%) to 0.2" (30%) to 0.5" (10%) LOW
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.