Safety should be first and foremost on the mind of a spotter. Remember, the NWS values your safety more than we do your observations. It is essential that spotters proceed into the field armed not only with knowledge of the storms but also with an understanding of the dangers posed by thunderstorms.

When spotting, travel in pairs if at all possible. When moving, this will allow the driver to remain focused on the chore of driving while the passenger keeps an eye on the sky and handles any communication with the dispatcher. When stopped, two sets of eyes are available for observation.

Keep aware of the local environment at all times. When in the vicinity of a thunderstorm, keep a 2-mile "buffer zone" between you and the storm. Frequently check the sky overhead and behind to ensure no unexpected events (such as a new tornado) are developing. Always have an escape route available, in case threatening weather approaches or if you get within the 2-mile "buffer zone."

Lightning is the number one killer among weather phenomena. During a typical year, lightning kills more people than hurricanes, tornadoes, and winter storms combined. The two main threats posed by lightning are the intense heat of the lightning stroke (about 15,000 degrees Celsius) and the extreme current associated with the stroke, estimated at 30,000 amperes (less than 1 ampere can be fatal).

Lightning is also the biggest weather hazard facing the spotter. When in the field, the spotter will usually be in a preferred lightning strike area (in the open, on a hilltop, etc.). Whenever possible, remain in your spotting vehicle to minimize the chance of being struck by lightning. If you must leave your vehicle, crouch as low as possible to make yourself a less-favorable target.

Hail is usually not a direct threat to life, but hailstorms are the costliest weather element to affect the United States. Each year, hailstorms cause over $1 billion in damage primarily to crops, livestock, and roofs. Giant hailstones (2 inches or more in diameter) can reach speeds of 100 miles an hour as they fall to earth. If such a stone strikes someone, the results can be fatal. There have been only two documented hail-related deaths in the United States, but a hailstorm in China killed over 100 people in 1976. A vehicle will usually offer adequate protection from moderate-sized hailstones. Hail larger than golfball size may damage windshields, so avoid large hailshafts if at all possible.

Downbursts are underrated thunderstorm threats. A downburst is defined as a strong downdraft with an outrush of damaging winds on or near the earth's surface. Downbursts are responsible for the "wind shear" which has caused a number of airliner accidents in the 1970's and early 1980's. When people experience property damage from a downburst, they often do not believe that "just wind" could have caused the damage, and they assume that they were struck by a tornado. In fact, the strongest downbursts have wind gusts to near 130 miles an hour and are capable of the same damage as a medium-sized tornado.

Downbursts are classified based on their size. If the swath of damaging winds is 2.5 miles or greater, it is called a macroburst. If the swath is less than 2.5 miles across, it is called a microburst. In general, macrobursts are long-term, large-scale events, while microbursts are intense, quick-hitting phenomena. Microbursts are subdivided as wet or dry microbursts, depending on how much rain falls with the microburst. If very heavy rain falls with the microburst, it is called a wet microburst, while a dry microburst has little or no rain reaching the ground. Chapter Vlll discusses downbursts in more detail and outlines some spotting tips regarding downbursts.

Flash floods are another example of an underrated thunderstorm threat. Over the past several years, more people have been killed in flash floods than in tornadoes. Two factors are responsible for this. First, we have urbanized. Where rain water used to have open fields in which to run off, it now has highway intersections, basements, streets, etc. Second, the public as a whole is apathetic about flash flooding. We simply do not treat flash flooding with the respect it deserves. Many of the recent deaths associated with flash flooding have occurred because people attempted to drive their vehicles across a flooded low-water crossing and were swept away by the floodwaters. Less than two feet of moving water is needed for a vehicle to be swept away.

When spotting in a flash flood situation, follow these common sense safety tips. Remember that flash flooding is most dangerous at night when the effects of flash flooding are difficult to see. Since most flash floods occur at night, this problem is compounded. Avoid low water crossings and don't drive into areas where water covers the road. If you are caught m a flash flood, abandon your vehicle and quickly get to higher ground.

Last but not least is the tornado. Again, a tornado is defined as a violently rotating column of air in contact with the ground and pendant from a thunderstorm (whether or not a condensation funnel is visible to the ground). If the violently rotating column of air has not touched the ground, it is called a funnel cloud. We will discuss the tornado in more detail in Chapter IX.

If a tornado is approaching your location, drive away from the tornado IF you are in open country, IF the location and motion of the tornado are known, and IF you are familiar with the local road network. If you are in an urban area and escape is not possible for some reason, abandon your vehicle and get into a reinforced building. If a reinforced building is not available, get into a culvert, ditch, or other low spot in the ground (that is not flooded).

Spotting at night is obviously more difficult than spotting during the day. There are only a few allies available to help you when night spotting. If possible, use the light from lightning flashes to illuminate the important parts of the storm. Quite often, though, lightning strokes will be very brief and will illuminate different parts of the storm from different angles. This will make it even more difficult to accurately report what is occurring. If you are in large hail, the most dangerous part of the storm is near you and will probably move overhead within a few minutes. If you hear a loud roaring sound, then a tornado may be very close to your location. Use this tip with caution. Not all tornadoes have a loud roar, and some non-tornadic winds may also possess a loud roar. Finally, if you think there is a tornado not far from your location (i.e., within spotting range), search along the horizon for bright flashes of light as the tornado destroys power lines and transformers.
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