Time: 421 PM Tue August 4, 2020 Forecaster: Brad Simmons

Internal Message Status
Flash Flood Prediction Program

MESSAGE 1'S ISSUED FOR THE ENTIRE DISTRICT
-Message 1's have been issued for the entire District and will be valid until 9:30pm this evening.
-Strong to severe thunderstorms are expected to develop over the next few hours with the potential to produce brief heavy rainfall as well as severe weather in the form of gusty straight-line winds and large hail. Strongest storms will likely favor areas E of I-25. Storms will move fairly quickly from NE to SE at around 25mph.
-Shower and thunderstorm activity is expected to decrease between 8-9pm.
STORM RAINFALL POTENTIAL AND DURATION: Moderate to strong thunderstorms will have the potential to produce 0.3-0.9" in 10-30 mintues. Supplemental QPF is available at https://qpf.udfcd.org

WORST CASE SCENARIO: A large slower moving thunderstorm or training of thunderstorm cells may produce rainfall amounts of up to 1.8" in 45-60 minutes.

County Message Valid Times Prime Time
Boulder County 1 Current TO 930 PM 500 PM TO 830 PM
Jefferson County 1 Current TO 930 PM 500 PM TO 830 PM
Broomfield County 1 Current TO 930 PM 500 PM TO 830 PM
Douglas County 1 Current TO 930 PM 500 PM TO 830 PM
Adams County 1 Current TO 930 PM 500 PM TO 830 PM
Denver County 1 Current TO 930 PM 500 PM TO 830 PM
DIA 1 Current TO 930 PM 500 PM TO 830 PM
Arapahoe County 1 Current TO 930 PM 500 PM TO 830 PM
the City of Aurora 1 Current TO 930 PM 500 PM TO 830 PM
Arvada 1 Current TO 930 PM 500 PM TO 830 PM
Wheat Ridge 1 Current TO 930 PM 500 PM TO 830 PM
Lakewood 1 Current TO 930 PM 500 PM TO 830 PM

County-specific Quantitative
Precipitation Outlook
Precipitation Time 30-Minute Rainfall
and % Probability
Message
Potential
Plains      
Adams Current TO 930 PM TUE
0.1" (80%) to 0.4" (60%) to 0.9" (20%) ISSUED
Arapahoe Current TO 930 PM TUE
0.1" (80%) to 0.4" (60%) to 0.9" (20%) ISSUED
Boulder Current TO 930 PM TUE
0.1" (80%) to 0.4" (50%) to 0.9" (15%) ISSUED
Broomfield Current TO 930 PM TUE
0.1" (80%) to 0.4" (50%) to 0.9" (15%) ISSUED
Denver Current TO 930 PM TUE
0.1" (80%) to 0.4" (60%) to 0.9" (20%) ISSUED
Douglas Current TO 930 PM TUE
0.1" (80%) to 0.4" (60%) to 0.9" (20%) ISSUED
Jefferson Current TO 930 PM TUE
0.1" (80%) to 0.4" (50%) to 0.9" (15%) ISSUED
Foothills above 6500ft      
Boulder Current TO 930 PM TUE
0.1" (85%) to 0.4" (50%) to 0.9" (15%) ISSUED
Douglas Current TO 930 PM TUE
0.1" (85%) to 0.4" (50%) to 0.9" (15%) ISSUED
Jefferson Current TO 930 PM TUE
0.1" (85%) to 0.4" (50%) to 0.9" (15%) ISSUED
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.