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Winter weather – What does that weather warning mean?

Tuesday, October 20th, 2020 4:49am MDT
You have seen and heard the warnings but do you know what they really mean?

You have seen and heard the warnings but do you know what they really mean?

We all are familiar with the crawls on the TV screen or the announcements on the radio for winter weather advisories such as Winter Storm Watch, Blizzard Warning, Freeze Warning and more. But, how many of us really know what those mean? There is very specific criteria the National Weather Service follows in issuing these watches and warnings and there are important differences between all of them.

In this second in a series on Winter Weather Preparedness from the National Weather Service, ThorntonWeather.com helps you understand what all of these mean so you can be better prepared.

600 AM TUE OCT 20 2020

From the National Weather Service:

What does that warning mean?

When a warning is issued during the winter season, will you know what it means, and will you know how to respond? During this Colorado Winter Weather Preparedness Week, please become familiar with our list of potentially life-saving winter weather products.

This statement contains warning and advisory criteria for Colorado east of the continental divide. Criteria west of the divide will be provided today in a separate issuance by the Grand Junction forecast office.


A Hazardous Weather Outlook is issued daily by each National Weather Service office serving Colorado. The outlook provides information on potentially hazardous weather out to 7 days into the future. Also, the Weather Story, a graphic of expected hazardous weather, is posted daily on National Weather Service web sites serving Colorado.

Watches and Warnings

A Winter Storm Watch is issued when hazardous winter storm conditions are possible within the next 3 to 4 days, but the timing, intensity, or occurrence may still be uncertain.

In contrast, a Winter Storm Warning is issued for potentially life-threatening winter storm conditions, such as heavy snowfall or a combination of snowfall and blowing snow, which are likely to occur within the next 1 to 2 days.

Warning criteria for heavy snow is defined by the following amounts.

  • For the mountains – 8 inches of snow accumulation in 12 hours or 12 or more inches in 24 hours.
  • For the lower elevations – 6 inches of snow accumulation in 12 hours or 8 or more inches in 24 hours.

A Blizzard Warning is issued when the following conditions are expected to occur for at least 3 hours:

  • Sustained winds of 35 mph or greater.
  • Considerable falling and/or drifting snow lowering
  • Visibilities to less than a quarter mile.

A high wind warning is issued:

  • Mountains…sustained winds 50 mph or more, or gusts of at least 75 mph.
  • Lower Elevations…sustained winds of 40 mph or more, or gusts of at least 58 mph

A Wind Chill Warning will be issued for the following wind chill temperatures:

  • Mountains…minus 35 degrees Fahrenheit or colder.
  • Lower Elevations…minus 25 degrees Fahrenheit or colder.

A Dust Storm Warning will be issued for the following conditions:

  • Visibility reduced to 1/4 mile or less in blowing dust and sustained winds of 25 mph or greater for at least one hour.


Advisories for winter weather are issued for potentially hazardous conditions which are considered more of a nuisance than a life-threatening situation. However, if caution is not taken the advisory events could become life-threatening

This week is Winter Weather Preparedness Week in Colorado. Public information statements will be issued throughout the week to give safety information and help you know how to respond when winter weather threatens.

Winter weather watches and advisories.

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