Air Quality Alert
COC035-031-013-069-005-123-059-001-014-212200-
Douglas-Denver-Boulder-Larimer-Arapahoe-Weld-Jefferson-
Adams-Broomfield-
410 PM MDT Thu Aug 20 2026
...OZONE ACTION DAY ALERT FROM 400 PM THURSDAY UNTIL 400 PM
FRIDAY...
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 August 20 to 400 PM Friday August 21
IMPACTS...Ozone Action Day Alert is now in effect for the Front
Range Urban Corridor. Hot, sunny, and stagnant weather will allow
ozone to reach the Unhealthy for Sensitive Groups concentration on
Thursday and Friday. The highest concentrations are expected in
southern and western portions of the Denver Metro Area. 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.
Friday, August 21, 2026. 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.
$$
Hazardous Weather Outlook
Hazardous Weather Outlook
National Weather Service North Platte NE
307 PM CDT Thu Aug 20 2026
NEZ004>010-022>029-035>038-056>059-069>071-094-212015-
Sheridan-Eastern Cherry-Keya Paha-Boyd-Brown-Rock-Holt-Garden-Grant-
Hooker-Thomas-Blaine-Loup-Garfield-Wheeler-Arthur-McPherson-Logan-
Custer-Deuel-Keith-Perkins-Lincoln-Chase-Hayes-Frontier-
Western Cherry-
307 PM CDT Thu Aug 20 2026 /207 PM MDT Thu Aug 20 2026/
This Hazardous Weather Outlook is for portions of western and north
central Nebraska.
.DAY ONE...This afternoon and tonight.
Isolated to widely scattered thunderstorms remain possible through
this evening, mainly for areas along and east of Highway 83 and north
of Highway 2. Any storms that form will pose a risk for large to
very large hail, damaging winds, and locally heavy rainfall.
Renewed thunderstorm development is possible in the predawn hours
Friday, mainly for portions of central Nebraska. Should activity
develop, a few could be strong to severe with large hail, damaging
winds, and locally heavy rainfall the main concerns.
.DAYS TWO THROUGH SEVEN...Friday through Wednesday.
Isolated to scattered thunderstorms chances return Friday
afternoon/evening across western and north central Nebraska.
Confidence in precise evolution of the thunderstorm threat is limited
as morning activity may hamper the afternoon environment. Should
the environment recover and storms develop, strong to severe storms
will again be possible with large to very large hail and damaging
winds the primary threats. The main area of concern is generally
east of Highway 61. Continue to monitor later forecasts for up to
date thinking on the concern.
Thunderstorms will continue to be possible daily from Saturday
through Wednesday. At this time, the severe threat is uncertain.
.SPOTTER INFORMATION STATEMENT...
Spotter activation may be needed.
$$
