Time: 943 AM Sun July 7, 2019 Forecaster: Justin Brooks

Heavy Precipitation Outlook
Flash Flood Prediction Program

WARM TODAY WITH A CHANCE OF AN ISOLATED HIGH BASED SHOWER/THUNDERSTORM
-Drier air is moving into the District from the west/southwest today as high pressure remains over Eastern Colorado. This will result in warmer temperatures today with highs getting into the mid to upper 80's on the plains.
-Enough lingering moisture remains for isolated high based thunderstorms to develop across the District this afternoon. Storms will initially develop over the foothills in the early afternoon, before spreading onto the plains during the mid to late afternoon hours. Storm activity should quickly taper off this evening with the loss of daytime heating.
-Moisture will be on the decrease today with dew points projected to fall into the upper 30's to low 40's this afternoon. Storm movement will be from west to east with typical storm motions at 10-15mph, but some storms could stall over an area for a short period of time due to outflow boundary development. If a stronger thunderstorm manages to develop, then the potential will exist for localized moderate to heavy rainfall.
STORM RAINFALL POTENTIAL AND DURATION: Typical weak to moderate thunderstorms will produce rainfall amounts of Trace-0.3" in 10-30 minutes. A strong thunderstorm will be capable of producing heavy rainfall of 0.3-0.6" in 10-30 minutes.

WORST CASE SCENARIO: A strong thunderstorm stalls over an area, resulting in heavy rainfall of up to 1.0" in 45-75 minutes.

A LOOK AHEAD: A short-wave trough will move over the region Monday bringing a better chance for storm development across the District in the afternoon and evening. With adequate upper level support, and an uptick in available moisture, some storms will have the potential for heavy rainfall, hail and strong winds. Tuesday will begin to dry out slightly, although a chance for a brief high based afternoon rain shower/isolated thunderstorm will be present, but the risk for heavy rainfall will be very low. Wednesday, SW flow returns resulting in a more active pattern once again through the rest of the week along with warmer temperatures with the 90's returning by Thursday.

Location Prime Time 30-Minute Rainfall
and % Probability
Message
Potential
Plains      
Adams 200 PM TO 800 PM
Trace (70%) to 0.3" (40%) to 0.6" (10%) LOW
Arapahoe 200 PM TO 800 PM
Trace (70%) to 0.3" (40%) to 0.6" (10%) LOW
Boulder 200 PM TO 800 PM
Trace (70%) to 0.3" (30%) to 0.6" (10%) LOW
Broomfield 200 PM TO 800 PM
Trace (70%) to 0.3" (30%) to 0.6" (10%) LOW
Denver 200 PM TO 800 PM
Trace (70%) to 0.3" (40%) to 0.6" (10%) LOW
Douglas 200 PM TO 800 PM
Trace (70%) to 0.3" (40%) to 0.6" (10%) LOW
Jefferson 200 PM TO 800 PM
Trace (70%) to 0.3" (30%) to 0.6" (10%) LOW
Foothills above 6500ft      
Boulder 200 PM TO 800 PM
Trace (70%) to 0.3" (30%) to 0.6" (10%) LOW
Douglas 200 PM TO 800 PM
Trace (70%) to 0.3" (30%) to 0.6" (10%) LOW
Jefferson 200 PM TO 800 PM
Trace (70%) to 0.3" (30%) to 0.6" (10%) LOW
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.