SKYWARN ONLINE - Winter Weather

This year's winter weather season has been particularly active in several regions of the United States with record snowfalls, dangerous blizzards, and paralyzing temperatures plaguing many states. One of the most effective ways to remain safe during major winter storms is to be informed of changing weather conditions and knowing the terminology the National Weather Service uses for various forms of winter weather.

Watches
A Winter Storm Watch is usually issued 12 to 48 hours in advance when severe winter weather may affect a certain area including heavy snow, accumulating amounts of freezing rain or sleet, reduced visibilities due to blowing snow, or a combination of any of these weather events. Heavy snow is generally defined as 4 or more inches of snow during a 12-hour period, or 6 or more inches within 24 hours.

Warnings
A Winter Storm Warning will be issued when severe or significant winter weather conditions are occurring or forecasted to occur within 24 hours an may be potentially life-threatening. The criteria for issuing a Winter Storm Warning varies from region to region.

When a Blizzard Warning is issued by the NWS, this indicates that brutal winter weather conditions of large amounts of falling or blowing snow and sustained winds of at least 35 mph are expected to occur over a prolonged period of time. These winds can create white-out or near white-out conditions with reduced visibilities to less than a quarter of a mile for three hours or more with blowing and drifting snow making traveling or being outdoors especially hazardous. The strong winds often times will also create bitterly cold wind chills that will last for several hours as well.

An Ice Storm Warning is issued when significant amounts of accumulating ice are forecasted due to freezing rain. Typically, the criteria for an Ice Storm Warning is when more than 1/4 ice is expected to occur over a 24 hour period. Ice storms may cause a significant amount of damage and power outages that may last for several days or weeks.

Wind Chill Warnings are generally issued when the wind chill is forecasted to be -35F or more below zero and exposure without adequate protection may lead to frost bite, hypothermia, and death.

Advisories
A Winter Weather Advisory will be issued when winter weather conditions may be hazardous or cause a significant inconvenience but not considered to be life-threatening if caution is exercised. Winter Weather Advisories can be included for snow, freezing drizzle, and blowing snow.

A Snow/Blowing Snow Advisory is issued when wind driven snow reduces visibility and makes traveling an inconvenience.

Freezing Rain Advisories are issued when accumulations of freezing rain that cause hazardous driving conditions are on-going or forecasted to occur within 24 hours with ice accumulations less than 1/4 of an inch.

A Wind Chill Advisory is issued when the wind chill temperature is expected to fall between -15°F and -24°F and precautions should be implemented while being outdoors.

Winter Weather Preparation Tips
Major winter storms can be dangerous and lethal. Preparing and protecting yourself from the harsh elements associated with winter weather can reduce the dangers caused by winter storms. Here are some winter weather preparedness tips:

Items for home:

At least a three day supply of bottled water and non-perishable food items
A flashlight with extra batteries
Battery powered radio
Candles/lantern and matches
Portable heater or firewood for the fireplace (if there is no power.)
Smoke and Carbon Monoxide Detector

While being outdoors, wear:

Multiple layers of loose fitting clothing
Gloves
Hat
Scarf

For your vehicle, make sure it’s been weatherized for winter including tires with good traction. Be sure to keep in your vehicle:

Jumper cables
Sand or kitty litter
Shovel
Ice scrapper
Blankets
Non-perishable food and water
Flashlight and batteries
Candles and matches

Also, before traveling:

Check for weather updates on the radio, the NWS, or media source
Check the latest road conditions
Let people know where and when you are traveling