Time: 854 AM Wed August 25, 2021 Forecaster: Justin Brooks

Heavy Precipitation Outlook
Flash Flood Prediction Program

HOT AND A LITTLE HAZY TODAY WITH A CHANCE FOR AN ISOLATED EVENING RAIN SHOWER/THUNDERSTORMS
-High-pressure continues to hold over the region today resulting in another hot and slightly hazy day today as high temperatures reach the upper 80's to low 90's across the plains with low to mid 80's along the foothills.
-Dry conditions are likely throughout most of the day for the District, however a slight chance for an evening round or rain showers/isolated thunderstorms. At this time, storms chances favor areas just north of the District and towards the eastern plains. Best chance for storms this evening will be from 6-10pm with skies gradually clearing through the overnight and into Thursday. Currently models suggest decent development to the north of the District which could result in a gust front which could potentially trigger additional, slow moving storms southward and into the northern portion of the District resulting in a low chance for a heavy rainfall threat at this time. If these storms are able to develop, it will increase the threat for heavy rainfall this evening.
-Overnight should be mild as lows drop into the upper 50's to low 60's on the plains with upper 40's to low 50's for the foothills.
STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers/isolated thunderstorms will produce a TR-0.2" of rainfall in 10-30 minutes. A moderate to strong thunderstorm will be able to produce 0.2-0.4" in 10-30 minutes.

WORST CASE SCENARIO: A slower moving or stationary moderate to strong thunderstorm has the potential to produce 1.2" of rainfall in 60-90 minutes.

A LOOK AHEAD: A disturbance will move through the region Thursday bringing slightly cooler high temperatures along with a better chance for widespread afternoon and early evening rain showers/thunderstorms. There will also be a slight chance for severe weather including gusty winds, large hail and heavy rain. Warmer Friday as high temperatures jump back into the low to mid 90's. A slight chance Friday afternoon and early evening for scattered rain showers/isolated thunderstorms. Similar conditions Saturday as high temperatures remain in the low 90's along with dry conditions at this time.

Location Prime Time 30-Minute Rainfall
and % Probability
Message
Potential
Plains      
Adams 500 PM TO 1000 PM
Trace (50%) to 0.2" (40%) to 0.5" (10%) LOW
Arapahoe 500 PM TO 1000 PM
Trace (40%) to 0.2" (20%) to 0.5" (10%) LOW
Boulder 500 PM TO 1000 PM
Trace (60%) to 0.2" (40%) to 0.5" (15%) LOW
Broomfield 500 PM TO 1000 PM
Trace (50%) to 0.2" (40%) to 0.5" (15%) LOW
Denver 500 PM TO 1000 PM
Trace (40%) to 0.2" (20%) to 0.5" (10%) LOW
Douglas 500 PM TO 1000 PM
Trace (40%) to 0.2" (20%) to 0.5" (5%) NONE
Jefferson 500 PM TO 1000 PM
Trace (40%) to 0.2" (20%) to 0.5" (10%) LOW
Foothills above 6500ft      
Boulder 500 PM TO 1000 PM
Trace (60%) to 0.2" (40%) to 0.5" (20%) LOW
Douglas 500 PM TO 1000 PM
Trace (40%) to 0.2" (20%) to 0.5" (5%) NONE
Jefferson 500 PM TO 1000 PM
Trace (40%) to 0.2" (20%) to 0.5" (5%) NONE
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.
https://f2p2.udfcd.org/generator/