Knoxville — Let's begin with wind chill.
It represents the effect of cold temperatures and wind on the human body…. But there is more to it than just how cold it FEELS outside.
The National Weather Service uses a chart to determine how dangerous the combination of temperature and wind are to exposed skin.
One of the side effects of being outside in extreme conditions is frostbite.
This happens when skin is exposed to extreme cold and typically affects the nose, fingers or toes.
The tissue can be damaged or may die and amputation is sometimes necessary…. Always be sure to dress properly for weather conditions.
A word you may sometimes hear in addition to the typical winter precipitation types like snow and freezing rain is graupel.
It’s basically soft hail or snow grains or pellets. It forms when supercooled water droplets collect and freeze on falling snowflakes, forming tiny balls of ice.
And not every snow storm is a “blizzard”.
To be defined as a blizzard, you must have:
- Sustained winds or frequent gusts of 35 mph or greater.
- Falling and/or blowing snow that reduces visibility to less than a quarter of a mile.
- And these conditions must persist for at least 3 consecutive hours.
Something you will commonly see during the cold months is rime ice.
It can sometimes look like snow on trees in higher elevations but it is actually created from freezing fog.
It can create some beautiful scenery in the mountains of East Tennessee.
Something that looks a lot like rime ice but forms from a different process is hoarfrost (yes, you read that correctly).
You’ll see white crystals that form on vegetation or other objects such as spider webs or trees on some of the coldest winter nights.
Last but not least, you should know the difference between a winter storm watch vs. warning.
A WATCH is issued when there is the POTENTIAL for hazardous winter weather in the next 48 hours.
A WARNING means hazardous winter weather IMMINENT OR OCCURRING.
Those are just a few of the words you’ll hear as we move into the winter season!