Time: 1109 AM Sat July 25, 2020 Forecaster: Brad Simmons

Internal Message Status
Flash Flood Prediction Program

MESSAGE 1'S ISSUED FOR THE ENTIRE DISTRICT VALID FROM NOON TO 10PM
-Message 1's have been issued for the entire District and will be valid from Noon until 10pm this evening. Thunderstorms are expected to begin to develop over the coming hours and will be very capable of producing heavy rainfall that may lead to excessive runoff and possibly flash flooding.
-Once again, 2-3 rounds of showers and thunderstorms are expected into the evening. Prime time for thunderstorms looks to be from 1-9pm. After 9 or 10pm lingering rain showers will remain possible overnight.
-Showers and thunderstorms will be relatively fast moving from SW to NE at around 25mph which will help to reduce point rainfall amounts from a single storm. Training of thunderstorm cells or a larger thunderstorm will have the potential to produce extended periods of heavy rainfall.
STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers and weak to moderate thunderstorms will produce 0.1-0.5" in 10-30 minutes. Strong thunderstorms will have the potential to produce 0.5-1.5" in 10-30 minutes. Supplemental QPF is available at https://qpf.udfcd.org

WORST CASE SCENARIO: Training of thunderstorm cells or a very large slower moving thunderstorm may produce up to 2.6" of rain in 45-60 minutes.

County Message Valid Times Prime Time
Lakewood 1 1200 PM TO 1000 PM 100 PM TO 900 PM
Wheat Ridge 1 1200 PM TO 1000 PM 100 PM TO 900 PM
Arvada 1 1200 PM TO 1000 PM 100 PM TO 900 PM
the City of Aurora 1 1200 PM TO 1000 PM 100 PM TO 900 PM
Arapahoe County 1 1200 PM TO 1000 PM 100 PM TO 900 PM
DIA 1 1200 PM TO 1000 PM 100 PM TO 900 PM
Denver County 1 1200 PM TO 1000 PM 100 PM TO 900 PM
Adams County 1 1200 PM TO 1000 PM 100 PM TO 900 PM
Douglas County 1 1200 PM TO 1000 PM 100 PM TO 900 PM
Broomfield County 1 1200 PM TO 1000 PM 100 PM TO 900 PM
Jefferson County 1 1200 PM TO 1000 PM 100 PM TO 900 PM
Boulder County 1 1200 PM TO 1000 PM 100 PM TO 900 PM

County-specific Quantitative
Precipitation Outlook
Precipitation Time 30-Minute Rainfall
and % Probability
Message
Potential
Plains      
Adams 100 PM TO 1000 PM
0.1" (100%) to 0.5" (65%) to 1.5" (20%) ISSUED
Arapahoe 100 PM TO 1000 PM
0.1" (100%) to 0.5" (65%) to 1.5" (20%) ISSUED
Boulder 100 PM TO 1000 PM
0.1" (100%) to 0.5" (65%) to 1.5" (20%) ISSUED
Broomfield 100 PM TO 1000 PM
0.1" (100%) to 0.5" (65%) to 1.5" (20%) ISSUED
Denver 100 PM TO 1000 PM
0.1" (100%) to 0.5" (65%) to 1.5" (20%) ISSUED
Douglas 100 PM TO 1000 PM
0.1" (100%) to 0.5" (65%) to 1.5" (20%) ISSUED
Jefferson 100 PM TO 1000 PM
0.1" (100%) to 0.5" (65%) to 1.5" (20%) ISSUED
Foothills above 6500ft      
Boulder 1200 PM TO 1000 PM
0.1" (100%) to 0.5" (65%) to 1.5" (20%) ISSUED
Douglas 1200 PM TO 1000 PM
0.1" (100%) to 0.5" (65%) to 1.5" (20%) ISSUED
Jefferson 1200 PM TO 1000 PM
0.1" (100%) to 0.5" (65%) to 1.5" (20%) ISSUED
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.