Time: 828 AM Mon July 20, 2020 Forecaster: Justin Brooks

Heavy Precipitation Outlook
Flash Flood Prediction Program

WARM TODAY WITH A SLIGHT CHANCE FOR AFTERNOON AND EVENING RAIN/ISOLATED THUNDERSTORMS
-Another warm day today as high temperatures reach the upper 80's to low 90's across the plains with upper 70's to low 80's along the foothills. W/NW flow aloft has brought in a bit drier air from the west with drier surface conditions as well as dew points remain in the low 40's today.
-A slight chance for scattered afternoon rain showers/isolated thunderstorms between 2-7pm, with a slightly better chance for a later round of rain showers/isolated thunderstorms between 7-10pm. Storm motions today will be on the quicker side between 10-20mph from the W/NW to E/SE, which will help limit point rainfall amounts this afternoon and evening, although brief localized heavy rainfall cannot be completely ruled out at this time . Skies will gradually begin to clear after 10pm.
-Overnight lows will drop into the upper 50's to low 60's. An increased chance Tuesday for rain showers/thunderstorms, with a decent chance of storms becoming severe, with heavy rainfall, along the I-25 corridor and eastward onto the plains.
STORM RAINFALL POTENTIAL AND DURATION: Rain showers and weak thunderstorms will produce a trace to 0.1" of rain in 10-30 minutes. A moderate thunderstorm could produce 0.1-0.3" in 10-30 minutes. Supplemental QPF is available at https://qpf.udfcd.org

WORST CASE SCENARIO: A strong, slow moving thunderstorm formed off an outflow boundary has the potential produce up to 1.2" in 30-60 minutes.

A LOOK AHEAD: This active weather pattern will hold through the week with an increased chance for heavy rain Tuesday. Wednesday, Thursday and Friday all have a chance for afternoon/early evening rain showers/isolated thunderstorms with storm chances increasing into the weekend as a monsoon type pattern begins across the region.

Location Prime Time 30-Minute Rainfall
and % Probability
Message
Potential
Plains      
Adams 200 PM TO 1000 PM
Trace (40%) to 0.1" (30%) to 0.3" (15%) NONE
Arapahoe 200 PM TO 1000 PM
Trace (40%) to 0.1" (30%) to 0.3" (15%) NONE
Boulder 200 PM TO 1000 PM
Trace (40%) to 0.1" (30%) to 0.3" (15%) NONE
Broomfield 200 PM TO 1000 PM
Trace (40%) to 0.1" (30%) to 0.3" (15%) NONE
Denver 200 PM TO 1000 PM
Trace (40%) to 0.1" (30%) to 0.3" (15%) NONE
Douglas 200 PM TO 1000 PM
Trace (40%) to 0.1" (30%) to 0.3" (15%) NONE
Jefferson 200 PM TO 1000 PM
Trace (40%) to 0.1" (30%) to 0.3" (15%) NONE
Foothills above 6500ft      
Boulder 200 PM TO 1000 PM
Trace (40%) to 0.1" (30%) to 0.3" (15%) NONE
Douglas 200 PM TO 1000 PM
Trace (40%) to 0.1" (30%) to 0.3" (15%) NONE
Jefferson 200 PM TO 1000 PM
Trace (40%) to 0.1" (30%) to 0.3" (15%) NONE
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.