Time: 832 PM Thu July 29, 2021 Forecaster: Brad Simmons

Internal Message Status
Flash Flood Prediction Program

MESSAGE 1'S CONITINUE VALID UNTIL 10PM FOR PORTIONS OF THE DISTRICT
-Message 1's will continue valid over NW portions of the District until 10pm although the threat for heavy rainfall is diminishing.
-A warm layer of air aloft has kept any moderate to strong storm development at bay despite moisture levels rising significantly from this morning as the 6pm sounding in Denver yielded 1.09" of precipitable water. A surface wind convergence line still exists over NW portions of the District but is is now washing out and reducing storm chances.
-There is still a slight chance for a stronger, slow moving thunderstorm to develop but now that temperatures are backing off as the sun sets this threat is much lower than just a couple hours ago. As time passes this evening the threat for heavy rainfall also diminishes likely allowing Messages to expire at 10pm.
STORM RAINFALL POTENTIAL AND DURATION: Rain showers and weak thunderstorms will produce a trace to 0.2" of rain. Moderate to strong thunderstorms will have the potential to produce 0.2-0.6" of heavy rain in 10-30 minutes.

WORST CASE SCENARIO: A stationary strong thunderstorm will have the potential to produce up to 1.2" in 30-60 minutes.

County Message Valid Times Prime Time
Adams County 1 Current TO 1000 PM Current TO 900 PM
Broomfield County 1 Current TO 1000 PM Current TO 900 PM
Jefferson County 1 Current TO 1000 PM Current TO 900 PM
Boulder County 1 Current TO 1000 PM Current TO 900 PM

County-specific Quantitative
Precipitation Outlook
Precipitation Time 30-Minute Rainfall
and % Probability
Message
Potential
Plains      
Adams Current TO 1000 PM THU
Trace (50%) to 0.2" (20%) to 0.6" (10%) ISSUED
Arapahoe Current TO 1000 PM THU
Trace (25%) to 0.2" (10%) to 0.6" (5%) LOW
Boulder Current TO 1000 PM THU
Trace (60%) to 0.2" (30%) to 0.6" (10%) ISSUED
Broomfield Current TO 1000 PM THU
Trace (50%) to 0.2" (20%) to 0.6" (10%) ISSUED
Denver Current TO 1000 PM THU
Trace (25%) to 0.2" (10%) to 0.6" (5%) LOW
Douglas Current TO 1000 PM THU
Trace (25%) to 0.2" (10%) to 0.6" (5%) LOW
Jefferson Current TO 1000 PM THU
Trace (50%) to 0.2" (20%) to 0.6" (10%) ISSUED
Foothills above 6500ft      
Boulder Current TO 1000 PM THU
Trace (90%) to 0.2" (60%) to 0.6" (15%) ISSUED
Douglas Current TO 1000 PM THU
Trace (25%) to 0.2" (10%) to 0.6" (5%) LOW
Jefferson Current TO 1000 PM THU
Trace (50%) to 0.2" (20%) to 0.6" (10%) ISSUED
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.
https://f2p2.udfcd.org/generator/