Weather Alert in Colorado
Air Quality Alert issued June 19 at 4:10PM MDT by NWS Denver CO
AREAS AFFECTED: Jefferson, CO; Weld, CO; Adams, CO; Larimer, CO; Arapahoe, CO; Douglas, CO; Boulder, CO; Broomfield, CO; Denver, 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 Thursday June 19 to 1200 AM Friday June 20 IMPACTS...Ozone Action Day Alert is now in effect for the Front Range Urban Corridor. Hot, stagnant weather on Thursday will allow ozone to reach the Unhealthy for Sensitive Groups category. The highest ozone concentrations are expected in southern and western portions of the Denver Metro area, along the I-25 corridor towards Fort Collins, and Greeley. Ozone levels will improve to the Good to Moderate range by Friday. 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 midnight, Thursday night, June 19, 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 is Rain?
Home - Education - Precipitation - Rain
Next Topic: Shelf Clouds
Precipitation in the form of water droplets is called rain.
Rain generally has a tendency to fall with less intensity over a greater period
of time, and when rainfall is more severe it is usually less sustained.
Rain is the most common form of precipitation and happens with greater frequency
depending on the season and regional influences. Cities have been shown to have
an observable effect on rainfall, due to an effect called the urban heat island.
Compared to upwind, monthly rainfall between twenty and forty miles downwind of
cities is 30% greater.
Next Topic: Shelf Clouds
Weather Topic: What is Sleet?
Home - Education - Precipitation - Sleet
Next Topic: Snow
Sleet is a form of precipitation in which small ice pellets are the primary
components. These ice pellets are smaller and more translucent than hailstones,
and harder than graupel. Sleet is caused by specific atmospheric conditions and
therefore typically doesn't last for extended periods of time.
The condition which leads to sleet formation requires a warmer body of air to be
wedged in between two sub-freezing bodies of air. When snow falls through a warmer
layer of air it melts, and as it falls through the next sub-freezing body of air
it freezes again, forming ice pellets known as sleet. In some cases, water
droplets don't have time to freeze before reaching the surface and the result is
freezing rain.
Next Topic: Snow
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