National Weather Service - Green Bay
Winter Driving Information from Wisconsin Department of Transportation
Regional Map of Winter Road Conditions for the Midwest
More winter weather awareness information
The University of Wisconsin, Space Science and Engineering Center has a regional map that shows winter road conditions for the Midwest. It is updated every 30 minutes.
Watches & Warnings
Winter weather related Warnings, Watches and Advisories are issued by your local National Weather Service office. Each office knows the local area and will issue Warnings, Watches or Advisories based on local criteria. For example, the amount of snow that triggers a “Winter Storm Warning” in the Northern Plains is typically much higher than the amount needed to trigger a “Winter Storm Warning” in the Southeast.
Warnings: Take Action!
Blizzard Warnings are issued for frequent gusts greater than or equal to 35 mph accompanied by falling and/or blowing snow, frequently reducing visibility to less than 1/4 mile for three hours or more. A Blizzard Warning means severe winter weather conditions are expected or occurring. Falling and blowing snow with strong winds and poor visibilities are likely, leading to whiteout conditions making travel extremely difficult. Do not travel. If you must travel, have a winter survival kit with you. If you get stranded, stay with your vehicle and wait for help to arrive.
Winter Storm Warnings are issued for a significant winter weather event including snow, ice, sleet or blowing snow or a combination of these hazards. Travel will become difficult or impossible in some situations. Delay your travel plans until conditions improve.
Ice Storm Warnings are usually issued for ice accumulation of around 1/4 inch or more. This amount of ice accumulation will make travel dangerous or impossible and likely lead to snapped power lines and falling tree branches. Travel is strongly discouraged.
Wind Chill Warning are issued for a combination of very cold air and strong winds that will create dangerously low wind chill values. This level of wind chill will result in frostbite and lead to hypothermia if precautions are not taken. Avoid going outdoors and wear warm protective clothing if you must venture outside. See the NWS Wind Chill Chart.
Lake Effect Snow Warnings are issued when widespread or localized lake induced snow squalls or heavy showers are expected to produce significant snowfall accumulation. Lake effect snow usually develops in narrow bands and impacts a limited area. These bands can produce very heavy snow with sudden restrictions in visibility. Driving conditions may become hazardous at times.
Watches: Be Prepared
Blizzard Watches are issued when there is a potential for falling and/or blowing snow with strong winds and extremely poor visibilities. This can lead to whiteout conditions and make travel very dangerous.
Winter Storm Watches are issued when conditions are favorable for a significant winter storm event (heavy sleet, heavy snow, ice storm, heavy snow and blowing snow or a combination of events.)
Wind Chill Watches are issued when there is the potential for a combination of extremely cold air and strong winds to create dangerously low wind chill values. See the NWS Wind Chill Chart.
Lake Effect Snow Watches are issued when conditions are favorable for a lake effect snow event. A potential exists for heavy accumulation of lake effect snow. Travel and commerce may be significantly affected.
Advisories: Be Aware
Winter Weather Advisories are issued when snow, blowing snow, ice, sleet, or a combination of these wintry elements is expected but conditions should not be hazardous enough to meet warning criteria. Be prepared for winter driving conditions and possible travel difficulties. Use caution when driving.
Freezing Rain Advisories are issued when light ice accumulation (freezing rain and/or freezing drizzle) is expected but will not reach warning criteria. Expect a glaze on roads resulting in hazardous travel. Slow down and use caution while driving because even trace amounts of ice on roads can be dangerous.
Wind Chill Advisories are issued when low wind chill temperatures are expected but will not reach local warning criteria. Extremely cold air and strong winds will combine to generate low wind chill readings. If you must venture outdoors, take precautions against frostbite and hypothermia. See the NWS Wind Chill Chart.
Lake Effect Snow Advisory are issued for widespread or localized lake effect snowfall accumulation (and blowing snow) remaining below warning criteria. Expects lake effect snow showers and assume travel will be difficult in some areas. Some localized snow bands will be intense enough to produce several inches in a few areas with sudden restrictions in visibility.
Here are some more key terms to understand:
Freezing Rain: Rain that freezes when it hits the ground; creating a coating of ice on roads, walkways, trees and power lines.
Sleet: Rain that turns to ice pellets before reaching the ground. Sleet also causes moisture on roads to freeze and become slippery.
Wind Chill: A measure of how cold people feel due to the combined effect of wind and cold temperatures; the Wind Chill Index is based on the rate of heat loss from exposed skin. Both cold temperatures and wind remove heat from the body; as the wind speed increases during cold conditions, a body loses heat more quickly. Eventually, the internal body temperature also falls and hypothermia can develop. Animals also feel the effects of wind chill; but inanimate objects, such as vehicles and buildings, do not. They will only cool to the actual air temperature, although much faster during windy conditions.
Find the current forecast at weather.gov.
Exposure to winter weather can become life-threatening.
Here are some conditions to be aware of:
Frostbite: Frostbite is damage to body tissue caused by freezing of the tissue. Frostbite causes a loss of feeling and a white or pale appearance in extremities, such as fingers, toes, earlobes or the tip of the nose. If symptoms are detected, get medical help immediately. If you must wait for help, slowly re-warm affected areas.
Hypothermia: Hypothermia occurs when the body temperature drops too low. Warning signs of hypothermia include uncontrollable shivering, memory loss, disorientation, slurred speech, drowsiness and apparent exhaustion. If a person's temperature is below 95 degrees Fahrenheit (35 C), seek medical care immediately. If medical care is not available, begin warming the person slowly. Get them into dry clothing and wrap them in a warm blanket, covering the head and neck. Do not give them hot beverages or food; warm broth is better. Do not warm extremities (arms and legs) first. This drives the cold blood toward the heart and can lead to heart failure.
Overexertion: Cold weather puts an added strain on the heart. Unaccustomed exercise such as shoveling snow or pushing a car can bring on a heart attack or make other medical conditions worse.
Pet Care: When temperatures fall, pets need extra care. Bring pets inside when temperatures reach 30 degrees with wind chill. Dogs and cats can get frostbitten ears, nose and feet if left outside. Outdoor dogs need a dry, elevated house, with clean, dry bedding and a flap over the opening to keep drafts out. Make sure water bowls are not frozen. Chemicals used to melt snow can irritate pets' paws. Be sure to keep antifreeze, salt and other household poisons away from pets.
Winter Storms & Extreme Cold