There are several atmospheric warning signs that precipitate a tornado's arrival:
- A dark, often greenish, sky.
- Wall clouds or an approaching cloud of debris.
- Large hail often in the absence of rain.
- Before a tornado strikes, the wind may die down and the air may become very still.
Similarly, you may ask, what is a nocturnal tornado?
During this period, when the days are short, nighttime tornadoes are a big risk. Deadly nocturnal tornadoes. Nighttime tornadoes occur most frequently in the nation's mid-South region, also known as Dixie Alley.
What time of the day do tornadoes form?
Although they are possible any time of the day or night, tornadoes tend to occur in the late afternoon and early evening hours, when the atmospheric conditions are most ripe for supercell thunderstorms. They are most common from 4pm to 9pm.
Safest Places to Be During a Tornado
- If you have a cellar, storm shelter, safe room or basement available, go immediately to that area.
- Get to a windowless interior room, such as a bathroom, closet or inner hallway.
- Stay as far from windows as possible.
- Go to the center of the room – corners tend to attract debris.
Find an interior room, hallway or stairwell – the more walls between you and the tornado, the better. Stay under a sturdy piece of furniture and protect your head. Move away from windows, and be sure to keep them closed, as high winds and dangerous debris can enter if they're opened.
When blue objects are illuminated with red light, Bachmeier says, they appear green. Green is significant, but not proof that a tornado is on the way. A green cloud “will only occur if the cloud is very deep, which generally only occurs in thunderstorm clouds,” Bachmeier says.
Rain, wind, lightning, and hail characteristics vary from storm to storm, from one hour to the next, and even with the direction the storm is moving with respect to the observer. While large hail can indicate the presence of an unusually dangerous thunderstorm, and can happen before a tornado, don't depend on it.
You can see that the red and green colors are very close together and relatively bright, showing strong rotation within the thunderstorm. Rotation on radar widely varies from storm to storm.
Beware of Hazards
- Keep away from downed power lines and report them to your utility company.
- Stay out of damaged buildings and homes until local emergency management officials have indicated it is safe to go inside them.
- Watch for snakes or other animals that have been forced into your home by rising waters or flooding.
Tornado: Flying debris is the major cause of death. Those in cars or mobile homes are in extreme danger during a tornado. Severe thunderstorms and derechos: Many of these overlap with flooding, lightning, and tornado deaths. Wind blown structures and debris in severe storms and derechos cause many deaths.
In the southern states, peak tornado season is from March through May. Peak times for tornadoes in the northern states are during the summer. A few southern states have a second peak time for tornado outbreaks in the fall. Tornadoes are most likely to occur between 3 p.m. and 9 p.m.
Tornado paths range from 100 yards to 2.6 miles wide and are rarely more than 15 miles long. They can last from several seconds to more than an hour, however, most don't exceed 10 minutes.
Like all natural disasters such as hurricanes, earthquakes, floods and others, they end up with massive destruction to homes, property, infrastructure and cause many deaths as well. Each year, about 60 people are killed by tornadoes, mostly from airborne debris. Source: noaa.gov.
If you are at home during a tornado:
- Go to a windowless interior room on lowest level of your house.
- Get away from the windows.
- Go to the center of the room.
- Get under a piece of sturdy furniture such as a workbench or heavy table or desk and hold on to it.
- Use your arms to protect head and neck.
Most thunderstorms occur in the late afternoon. By this time of day, the sun is beginning to set. The orange hue is caused by the same process that causes the vivid colors at sunsets. Shorter wavelengths of light (blue) are scattered quickly, leaving only the yellow-orange-red end of the spectrum.
What you need to do AFTER a tornado strikes
- Give first aid when appropriate.
- Turn on radio or television to get the latest emergency information.
- Stay out of damaged buildings.
- Use the telephone only for emergency calls.
- Clean up spilled medicines, bleaches, or gasoline or other flammable liquids immediately.
Most tornadoes are found in the Great Plains of the central United States – an ideal environment for the formation of severe thunderstorms. In this area, known as Tornado Alley, storms are caused when dry cold air moving south from Canada meets warm moist air traveling north from the Gulf of Mexico.
Experts don't agree on why the sky changes color before a tornado or severe thunderstorm. At least two theories suggest what might be the reason for the strange greenish-yellow color that (sometimes) precedes a storm. Theory #1. Because air molecules scatter light.
In a house with no basement, a dorm, or an apartment: Avoid windows. Go to the lowest floor, small center room (like a bathroom or closet), under a stairwell, or in an interior hallway with no windows. Crouch as low as possible to the floor, facing down; and cover your head with your hands.
A sequence of images showing the birth of a tornado. First, the rotating cloud base lowers. This lowering becomes a funnel, which continues descending while winds build near the surface, kicking up dust and debris and causing damage. As the pressure continues to drop, the visible funnel extends to the ground.
It is generally believed that tornadic wind speeds can be as high as 300 mph in the most violent tornadoes. Wind speeds that high can cause automobiles to become airborne, rip ordinary homes to shreds, and turn broken glass and other debris into lethal missiles.
About 1,000 tornadoes hit the United States every year. Most of these touch down in America's Plains states, an area known as Tornado Alley, which is generally considered to be Oklahoma, Kansas, the Texas Panhandle, Nebraska, eastern South Dakota, and eastern Colorado.
A tornado is a narrow, violently rotating column of air that extends from the base of a thunderstorm to the ground. Because wind is invisible, it is hard to see a tornado unless it forms a condensation funnel made up of water droplets, dust and debris. Tornadoes are the most violent of all atmospheric storms.