Time: 958 AM Thu May 28, 2020 Forecaster: Brad Simmons

Heavy Precipitation Outlook
Flash Flood Prediction Program

ISOLATED LATE AFTERNOON AND EVENING THUNDERSTORMS
-Temperatures will be a few degrees cooler today behind a weak surge that moved through early this morning with highs in the mid 70's to around 80 over the plains. Moisture has also increased from yesterday with dew points currently in the lower 50's.
-Thunderstorm activity looks to be capped through the early afternoon over the plains as a warm layer of air aloft slowly erodes. Isolated thunderstorms will become possible by 1-2pm over the higher terrain but should hold off until sometime between 2-4pm over the plains. There will then be a modest chance for thunderstorm activity through about 10pm this evening.
-Best chances for storm coverage today looks to be the southern half of the District and in particular Douglas County. Storms will move from NW to SE at around 15-20mph. Although storms are expected to be isolated, moderate to strong thunderstorms will be capable of producing brief heavy rainfall.
STORM RAINFALL POTENTIAL AND DURATION: Rain showers and weak thunderstorms will have the potential to produce a trace to 0.2" in 10-30 minutes. Moderate to strong thunderstorms will have the potential to produce 0.2-0.6" in 10-30 minutes.

WORST CASE SCENARIO: A large or slower moving strong thunderstorm will have the potential to produce 0.4-1.2" in 10-30 minutes as well as up to 2.0" in 60 minutes or less.

A LOOK AHEAD: Temperatures will warm well into the 80's over the plains on Friday with a continued chance for isolated afternoon and evening thunderstorms, some of which may produce brief heavy rain. The weekend will feature scattered afternoon thunderstorms with a higher threat for heavy rainfall along with temperatures in the 80's.

Location Prime Time 30-Minute Rainfall
and % Probability
Message
Potential
Plains      
Adams 300 PM TO 1000 PM
Trace (65%) to 0.3" (30%) to 0.6" (15%) LOW
Arapahoe 300 PM TO 1000 PM
Trace (75%) to 0.3" (40%) to 0.6" (15%) LOW
Boulder 300 PM TO 1000 PM
Trace (65%) to 0.3" (35%) to 0.6" (15%) LOW
Broomfield 300 PM TO 1000 PM
Trace (65%) to 0.3" (30%) to 0.6" (15%) LOW
Denver 300 PM TO 1000 PM
Trace (70%) to 0.3" (35%) to 0.6" (15%) LOW
Douglas 300 PM TO 1000 PM
Trace (85%) to 0.3" (45%) to 0.6" (20%) LOW
Jefferson 300 PM TO 1000 PM
Trace (75%) to 0.3" (40%) to 0.6" (15%) LOW
Foothills above 6500ft      
Boulder 200 PM TO 1000 PM
Trace (85%) to 0.3" (40%) to 0.6" (15%) LOW
Douglas 200 PM TO 1000 PM
Trace (95%) to 0.3" (45%) to 0.6" (20%) LOW
Jefferson 200 PM TO 1000 PM
Trace (85%) to 0.3" (40%) to 0.6" (15%) LOW
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.