The potential for heavy snow at higher elevations in the western U.S. will continue for many spots through the weekend. In the meantime, the eastern half of the continental U.S. will transition to above normal temperatures ahead of a pair of cold fronts next week that will bring readings back to closer to normal as we approach Thanksgiving Day. Read More >
The greatest danger is from flying debris (airborne missiles) and the collapse of a building's roof and/or wall structure. The following actions are designed for protection from these dangers. Take action if a tornado approaches or a Tornado Warning is issued.
In a building (home, school, etc.) move to the basement. If no basement, move to a small, interior room or hallway on the lowest level. Stay away from windows and exterior doors. If at all possible, get under something sturdy (such as a table) and place something over your head (such as a pillow, mattress, blanket, or coat) for added protection.
DO NOT STAY IN A MOBILE HOME OR ANY TYPE OF TEMPORARY SHELTER. If in a mobile home or temporary shelter, get out! Move away from the shelter so that the debris does not fall on you. Look for a low area, preferably a ditch or ravine if nearby. Take the protective position on your elbows and knees with your hands over your head.
DO NOT TRY TO OUTRUN A TORNADO IN A CAR, BUS, OR TRUCK. If in a car, bus, or truck, STOP. Get out. Move away from the vehicle so it does not topple on you. Find a low area, preferably a ditch or ravine if nearby. Take the protective position on your elbows and knees with your hands over your head.
If on foot with no well constructed shelter nearby, find a low area preferably a ditch or ravine if near by. Take the protective position on your elbows and knees with your hands over your head.
After the storm, if a tornado has struck your neighborhood, turn off gas at the main switch to your building. If live electrical wires are down, turn off power at the main switch. Instruct people not to touch loose electrical wires or broken utility lines. Do not touch electrical equipment in wet areas until it has been dried and tested. Food, clothing, shelter, and first aid will be available at Red Cross shelters.
The greatest danger comes from the high velocities with which large hail can impact a surface (speeds greater than 100 mph). To avoid getting hit with hail, one needs only to move inside. However, there are other considerations such as staying away from skylights. Hailstones can go through a vehicle's windshield. Hailstones driven by a storm's high winds may shatter a building's side windows.
A last consideration is that large hail is a sign that this is a powerful and potentially dangerous storm. Hail falls from the same area of a thunderstorm where the tornado is found. Large hail does not always imply a tornado, but if a tornado is associated with that storm and you are currently experiencing hail, then you may be very close to the tornado.
All thunderstorms produce lightning, by definition. If you can hear thunder, you are close enough to the storm to be struck. Take protective actions. Move inside. It need not be raining! Lightning can strike 10 to 15 miles away from the rain portion of the storm! These lightning strokes come out of the upper portions of the thunderstorm cloud which extends 5 to 10 miles into the atmosphere.
In general, lightning will travel the easiest route from the cloud to ground which means that it often strikes the highest object. Therefore, a simple rule is do not make yourself the tallest object or stand near the tallest object in your immediate surrounding. For instance, do not stand in an open field, on a beach, or on a hilltop. Do not stand under an isolated or large tree or near a pole. Do not stay out on a boat.
When lightning strikes, the current will travel through the object, along the ground, along wire, metal, and water. Most lightning related injuries occur in this matter. The electrical current will travel the easiest route. Stay away from metal objects such as fences, poles, equipment, pipes, etc. Get rid of metal objects on your body such as coins, money clips, hair pins, jewelry, etc. Stay away from water. If inside, stay away from electrical appliances, televisions, and telephones. Only use the phone in an emergency.
If caught outside and a thunderstorm approaches:
If a person is struck by lightning, check to see if the person is breathing. If not, begin mouth-to-mouth resuscitation. If no pulse is present, begin CPR (Cardiopulmonary resuscitation). Lightning often has a paralyzing effect that is temporary. Even though a person appears dead, they may be resuscitated. Victims may experience temporary paralysis of legs, be stunned and disoriented, or have burns on their body. Give first aid for shock and stay with the victim until help arrives. The victim is safe to touch.
After the storm, instruct people not to touch loose electrical wires or broken utility lines. Do not touch electrical equipment in wet areas until it has been dried and tested.
Flash floods are the most dangerous. A flash flood is rapid rise of flood waters allowing little time for action. Flash floods can move at tremendous speeds tearing out trees and moving boulders. The debris moves with the flood wave and sometimes destroys buildings and bridges in its path. Debris may cause a temporary dam and when broken a wall of water moves downstream. Walls of water can reach 10 to 20 feet. Floods and flash floods are the number one weather-related killer in the United States.
When a flood warning is issued or the moment you first realize that a flash flood is coming, act quickly to save yourself. You may only have seconds.
Get out of areas subject to flooding. This includes dips, low spots, canyons, washes, areas along streams and creeks. This also includes urban areas where storm drains become clogged with debris and rain, unable to be soaked up by the paved ground, rapidly building the flow of runoff. Some underpasses can be extremely dangerous, rapidly filling with water.
DO NOT ENTER FLOOD WATERS. DO NOT ATTEMPT TO CROSS FLOWING WATER IN A CAR OR TRUCK. Almost half of all flood deaths occur in automobiles. Water depths can be very deceptive; the road beneath may even be undermined. The force of flowing water on a vehicle is very powerful and a foot of water may be all it takes to drag a car into deeper waters or flip it over. Many cars stall once entering the water. Electrical systems in the car may fail causing electrical window and doors to not operate, trapping the victim inside as the water continues to rise.
If the vehicle stalls, abandon it immediately and seek higher ground. Rapidly rising water may engulf the vehicle and sweep it away.
After the storm, if a flood has struck your neighborhood, turn off gas at the main switch to your building. If live electrical wires are down, turn off power at the main switch. Instruct people not to touch loose electrical wires or broken utility lines. Do not touch electrical equipment in wet areas until it has been dried and tested. Do not touch fresh food that has come in contact with flood waters. Boil drinking water before using until water has been tested for purity. Food, clothing, shelter, and first aid will be available at Red Cross shelters.
The most severe winter storm is generally considered to be a blizzard (strong winds and blinding snow), but any heavy snow storms or ice storms can become life threatening. Most winter storm related deaths (about 60%) occur in automobiles. Some occur from exposure to cold (see extreme cold section), heart attacks from overexertion, fires from improper use of heaters, and other types of accidents.
Be prepared for the storm before it strikes. Listen to NOAA Weather Radio. If a Winter Storm Warning is issued, stay at home or, if need be, at work or school. Do not venture out into the storm. Winter storms (ice and snow) can close roads and knock out phones and electrical power for hours or a couple days in a bad storm. Have extra batteries, flashlights and a battery- powered, portable radio on hand. Have plenty of food (nonperishable, ready to eat) and water. Have a first-aid kit and extra medicines. Winterize your vehicles at the start of the season and keep your gas tank near full so ice doesn't form in the fuel lines. Have extra supplies in the vehicle in case you become stranded.
If caught in the storm, try to stay dry and warm. If in a car, bus, or truck, stay there, unless shelter can be seen just yards away. Disorientation in cold and snow occurs rapidly. Run the motor sparingly for heat. Open windows slightly to prevent carbon monoxide poisoning. If trapped at home, school, or work, and without heat, close off unneeded rooms. Stuff towels, rags or extra clothes in cracks under doors. Cover windows at night. If using an alternate heat source, such as a fireplace, wood stove, space heater, etc., follow directions, use fire safeguards, and ventilate properly.
If caught outside without shelter, make one. Dig a snow cave. Find an area protected from wind. Build a lean-to or wind break out of sticks and branches. Build a fire and place stones around the fire to absorb and reflect back heat. Do not eat snow for water -- it will drop your body temperature. You must melt it first. Exercise periodically, by rapidly moving arms, legs, fingers, and toes to keep blood circulating and to keep warm. If there is more than one person, sleep in shifts and help keep each other warm.
The people most often affected by cold are elderly and babies. However, if proper precautions are not taken, anyone can find him/herself suffering from hypothermia or frostbite.
Wind chill combines the rate of heat loss (from exposed skin) caused by wind and cold temperatures. As the wind increases, heat is carried away from a person's body at an accelerated rate driving down the body temperature. A 20 F temperature combined with a 20 mph wind produces a wind chill of -10 F.
Hypothermia occurs when the body temperature drops. Warning signs are uncontrollable shivering; loss of memory; disorientation; incoherence; vague, slow, slurred speech; frequent stumbling; drowsiness; apparent exhaustion or inability to get up from rest. If a person's body temperature drops below 95 F, seek medical help immediately.
If unable to get medical help, wrap the person in a warm blanket covering the head and neck. Do not give the person alcohol, drugs, hot liquid or hot food (warm is better). The person needs to be warmed slowly. Do not warm extremities (arms, legs, hands, etc.) first! This drives the cold blood toward the heart and can lead to heart failure. Warm the body core first. If needed, use your own body heat to help.
Frostbite is when the body tissue freezes, damaging the tissue. Frostbite causes a loss of feeling and a white or pale appearance in extremities, such as fingers, toes, ear lobes, 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.
To prevent hypothermia and frostbite, stay inside during extreme cold spells or heavy snow storms. If you must go out, dress appropriately. Wear loose-fitting, lightweight, warm clothing in several layers. Trapped cold air insulates. Avoid overexertion. The strain from the cold and hard labor (such as shoveling wet snow, walking through drifts, etc.) may lead to a heart attack. Sweating can lead to a chill and hypothermia. By wearing layers of clothes, if perspiration occurs, layers can be removed and then added back when needed. Outer garments should be tightly woven, water repellent, and hooded. Wear a hat. Half of your body's heat loss can be from your head. Cover your mouth (using a scarf, etc.) to protect your lungs from extreme cold. Mittens, snug at the wrist, are better than gloves for protecting the hands. Try to stay dry.
The human body dissipates heat by varying the rate and depth of blood circulation, by losing water through the skin and sweat glands, and (as the last extremity is reached) by panting when blood is heated above 98.6 F. The skin handles about 90% of the body's heat dissipating function. However, sweating does not cool the body unless the water is evaporated. Evaporation is a cooling process.
On hot days (temperature above 90 F) when the relative humidity is high, evaporation is retarded. The body attempts to do everything it can to maintain 98.6 F inside. The heart is pumping a torrent of blood through dilated circulatory vessels; the sweat glands are pouring liquid, including essential dissolved chemicals like sodium and chloride, onto the surface of the skin.
Heat disorders generally have to do with a reduction or collapse of the body's ability to shed heat by circulatory changes and sweating, or a chemical (salt) imbalance caused by too much sweating. When heat gain exceeds the level the body can remove, or when the body cannot compensate for fluids and salt lost through perspiration, the temperature of the body's inner core begins to rise and heat-related illness may develop.
Other factors : Cities can add to the hazard. Stagnant air conditions trap pollutants in urban areas and add the stresses of severe pollution to the already dangerous stresses of hot weather. Sunburn can significantly retard the skin's ability to shed excess heat. People on certain medication or drugs (such as tranquilizers and anticholinergics) and people overweight or with an alcohol problem are particularly susceptible.
What one should do to prevent heat disorders:
The Heat Index combines the effects of high temperature and relative humidity. Using the current temperature and relative humidity, calculate the heat index using the chart provided. Exposure to full sun can increase these values by up to 15 degrees. When the NWS is expecting the heat index to exceed 105 F, this will be headlined in the forecast. At Heat Indices above 105 F, possible heat disorders include heat cramps or heat exhaustion. Heat stroke is possible with prolonged exposure and/or physical activity.
Heat cramps are painful spasms usually in muscles of legs and abdomen. Use firm pressure on cramping muscles, or gentle massage to relieve spasm. Give sips of water unless nausea occurs.
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