October 20, 2015 8:30 AM
Winter Weather Preparedness: Outlooks, Watches & Warnings – What do they mean?
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 west of the continental divide. Criteria east of the divide will be provided today in a separate issuance by the Boulder 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.
Mountains...12 inches or more per storm event.
Lower Elevations...6 inches or more per storm event.
Or an early season or late season snowfall event having a significant impact but not meeting the above criteria
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,
and considerable falling and/or drifting snow
with visibilities frequently less than 1/4 mile.
A High Wind Warning is issued for the following conditions:
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.