Winter & Snow Advisories and Warnings Explanations

It's been at least a couple of years, maybe 3 or 4, that I last posted this, and I like to repost it every few years to remind everybody what each advisory covers. I really should have posted this in late October, as we can see these conditions anytime starting in September/October and have already had them issued here this season.

All of the following are issued when hazardous winter weather is occurring, imminent or likely. I'm only noting the warnings we see here and will skip the other winter advisories (like a freezing rain or drizzle advisory) that the National Weather Service (NWS) issues elsewhere, since that kind of weather never really ever occurs in our neck of the woods:

- A Winter Weather Advisory is issued for less serious winter weather conditions than warnings - but will still cause significant inconvenience.
- A Winter Storm Watch is issued when conditions are favorable for significant winter weather and/or blizzard conditions within the next three days, but the timing, intensity, or occurrence may still be uncertain.
- A Winter Storm Warning is issued when a combination of heavy snow, blowing snow, and possibly ice mixed with snow is expected to impact the area. Time to act! If caution is not exercised, such storms could lead to situations that may threaten life or property
- A Blizzard Warning is issued when the combination of strong wind, low visibility, and heavy snow will significantly impact daily life. Plus once again, if caution is not exercised, such storms could lead to situations that may threaten life or property. Blizzard conditions are also met when visibility in falling and blowing snow reaches ¼ mile or less.

- A Snow Squall Warning is an alert from the NWS that indicates a short, intense burst of heavy snowfall that can create dangerous driving conditions
- A Wind Chill Watch is issued when Wind Chill Warning criteria are possible in the next 12 to 36 hours.
- A Wind Chill Warning is issued for wind chills of at least minus 25 degrees on the plains, and minus 35 degrees in the mountains.

Some more on this:

A Blizzard Warning has different criterias for different areas. For one to be issued in the Rocky Mountains, the conditions noted above apply, but winds must be in excess of 50 mph. This criteria also applies to our Foothills and all higher elevations. For our Mountain Valleys and the Colorado Great Plains, the conditions noted above again apply, but winds don't have to be as high, as speeds of 35 mph or higher at lower elevations is all it takes for a Blizzard Warning to be issued. Plus, while large amounts of snow are usually expected, little or no snow at all can be expected when such a warning is issued, since blowing snow from past storms also can meet criteria for a Blizzard Warning to be issued.

Heavy snow criteria for Colorado also representative values applied by area: Mountains: 8 inches of snow in 12 hours and/or 12 or more inches in 24 hours. Lower elevations: 6 inches of snow in 12 hours and/or 8 or more inches in 24 hours.

For a Wind Chill Watch or Warning: As the wind increases, the body is cooled at a faster rate. The “wind chill” is a way for meteorologists to communicate what the combination of wind and temperature “feels like” to exposed skin. While wind chills negatively affect our bodies - and our pets bodies, they have no effects on other things like your car. While a vehicle's battery and other engine parts are effected negatively by the cold, they aren't effected by wind chill.

Our area rarely sees Snow Squall Warnigs issued here in the winter, as snow squalls are more likely to occuar in the spring here, plus they usually don't last all day long around here like they do in the U.S. Great Lakes. But yes, we can still see them in the winter months here, too.

A Freeze Watch and a Freeze Warning are issued when freezing conditions are possible in the next 12 to 36 hours. They are only issued during the growing season when widespread temperatures are expected to drop to below 32 degrees. Since these last two watches and warnings have already been issued and already reached this fall on more than two days, they will no longer be issued for the rest of this season.