Weather Alert in Colorado
Air Quality Alert issued July 11 at 4:10PM MDT by NWS Denver CO
AREAS AFFECTED: Boulder, CO; Weld, CO; Broomfield, CO; Denver, CO; Adams, CO; Jefferson, CO; Arapahoe, CO; Douglas, CO; Larimer, CO
DESCRIPTION: The Colorado Department of Public Health and Environment has issued the following... WHAT...Ozone Action Day Alert. WHERE...Douglas, Jefferson, Denver, western Arapahoe, western Adams, Broomfield, Boulder, Larimer, and Weld Counties WHEN...400 PM Friday July 11 to 400 PM Saturday July 12 IMPACTS...Ozone Action Day Alert is now in effect for the Front Range Urban Corridor. Unsettled weather will keep ozone in the Good to Moderate range on Friday. However, hot, stagnant weather on Saturday will allow ozone to reach the Unhealthy for Sensitive Groups level. For Colorado air quality conditions, forecasts, and advisories, visit: https://www.colorado.gov/airquality/colorado_summary.aspx If possible, please help us reduce ozone pollution by limiting driving gas and diesel-powered vehicles until at least 4 p.m. Saturday, July 12, 2025. Colorado is also addressing ozone pollution through state policies. For more information about health impacts and how ozone pollution forms in Colorado, visit: https://cdphe.colorado.gov/ozone- pollution-and-your-health HEALTH INFORMATION...Increasing likelihood of respiratory symptoms and breathing discomfort in active children and adults and people with lung disease, such as asthma. Active children and adults, and people with lung disease, such as asthma, should reduce prolonged or heavy outdoor exertion.
INSTRUCTION: N/A
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Weather Topic: What are Hole Punch Clouds?
Home - Education - Cloud Types - Hole Punch Clouds
Next Topic: Mammatus Clouds
A hole punch cloud is an unusual occurrence when a disk-shaped
hole appears in a cirrostratus, cirrocumulus, or altocumulus cloud.
When part of the cloud forms ice crystals, water droplets in the surrounding area
of the cloud evaporate. The effect of this process produces a large elliptical
gap in the cloud. The hole punch cloud formation is rare, but it is not specific
to any geographic area.
Other names which have been used to describe this phenomena include fallstreak hole,
skypunch, and cloud hole.
Next Topic: Mammatus Clouds
Weather Topic: What are Nimbostratus Clouds?
Home - Education - Cloud Types - Nimbostratus Clouds
Next Topic: Precipitation
A nimbostratus cloud is similar to a stratus cloud in its formless,
smooth appearance. However, a nimbostratus cloud is darker than a stratus cloud,
because it is thicker.
Unlike a stratus cloud, a nimbostratus cloud typically brings with it the threat
of moderate to heavy precipitation. In some cases, the precipitation may evaporate
before reaching the ground, a phenomenon known as virga.
Next Topic: Precipitation
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