BSA Weather Merit Badge


The following provide information for the weather merit badge requirements as numbered:


1(a). Define meteorology.

Meteorology is the study of atmospheric phenomena or weather.


1(b). How does weather affect:

Farmers - conditions that are too dry, too wet, too cold, or too hot can cause crop failure and poor harvests. Farmers need several days without rain to harvest hay. Farm animals (such as chickens or turkeys raised in North Carolina) can die if it gets too hot. Floods from Hurricane Floyd in 1999 devastated many farms in eastern NC. Hail and wind from thunderstorms can ruin many crops. Farmers need weather information to protect their crops and livestock with irrigation or shelter.

Sailors - people who sail boats depend on the wind. If the wind is too light, it takes a lot longer to travel somewhere. Too strong, and the boat may be overwhelmed by the wind and the waves. The direction of the wind is also critical to the route that the sailor will take to make best use of the wind to propel the boat.

Aviators - airplane pilots are very much affected by weather. If the clouds and visibility are too low, they may not be able to take off or land at an airport. If the winds are very gusty and changing in speed and direction over a short distance (called wind shear), they will have a very bumpy ride and may find it difficult to control the plane. If the wind is blowing against them, it will take longer and they will use more fuel (i.e. it will cost more) to get to their destination. If the wind is blowing with them in the direction of their flight, they will get there faster and use less fuel. Pilots look for the level in the atmosphere where the winds will give them the fastest and smoothest flight.

Construction companies - people who build things outdoors depend on accurate weather information to plan their projects. Rain will cause delays in earth moving projects such as building roads or excavating for a new buildings. Most paving materials cannot be set if precipitation occurs or temperatures fall below freezing. If it becomes too windy, building materials may be blown away and partially constructed buildings may be easily damaged.


2(a). Name five dangerous weather conditions and safety rules for each.

Tornadoes - A tornado is a violently spinning funnel of air that extends down from a cloud and touches the ground. Produced by a thunderstorm, a tornado sounds like a jet plane overhead or can make a noise like a freight train. At night, distant flashes of light from breaking power lines can signal an approaching tornado. In North Carolina, tornadoes are often hard to see, frequently hidden by heavy rain and may be preceded by large hail. Safety rules: seek shelter in a substantial building, in a small room like a bathroom or closet in the middle on the lowest floor or in the basement, if available. Stay away from windows. Get down and cover your head. If caught outdoors, crouch down in a ditch or ravine and cover your head. Get out of a mobile home or vehicle.

Severe thunderstorms - A thunderstorm becomes severe when it produces hail of penny size or greater or causes winds on the ground of 58 mph or more. Wind and hail of this intensity can cause damage and injuries. Also, any thunderstorm is capable of producing cloud to ground lightning that can be equally dangerous.. Lightning is second only to flooding in the number of people killed each year and strikes without warning. Safety rules: Use the 30/30 rule for lightning safety. If thunder is heard within 30 seconds after lightning is seen, it is within 6 miles of your location and you can be struck. Take shelter now, and stay sheltered until 30 minutes after the last thunder is heard because large bolts of lightning can strike outside the thundercloud often times several miles behind the storm. If caught outdoors, find a low spot away from water and away from isolated trees or metal structures. Keep a low profile. Keep feet together and crouch down and put your hands over your ears. If in a group, spread out and let go of metal objects. If in the woods, stay away from the tallest trees, away from the edge of clearings, and away from any dead trees or fallen snags or branches that may crash down in a sudden wind. Inside a car or truck is safe shelter from lightning.

Flash floods - Floods kill more people each year than any other type of weather related phenomena. Inland floods are often caused by very heavy rain from hurricanes or from groups of thunderstorms that cross the same area over and over. Moving water is very powerful and can wash away vehicles and buildings in flood prone areas. The risk of flooding increases with steeper terrain and paved or rocky surfaces. Safety rules: Do not camp near mountain streams or creeks or in deep valleys or urban drainage basins when thunderstorms are heard or expected. Seek higher ground immediately if a flash flood warning is heard or slow moving thunderstorms occur upstream in mountainous terrain. Never drive a vehicle across a flooded roadway. Water 18 inches deep can float your car or truck off the road. Never canoe or kayak on a flooded stream or river. And stay away from the edges of flooded creeks because the creek bank may crumble beneath your feet.

Winter storms - Winter storms can be life threatening when people become trapped in deep snow, thick ice, and/or bitter cold without a means of keeping warm. This can cause hypothermia when the body is unable to produce enough internal heat, or frost bite when parts of the body begin to freeze. Safety rules: Wear adequate clothing including poly-pro thermal underwear and an outer waterproof shell. Cover your head because most heat is lost from your head. Stay dry. Too much clothing and activity can cause sweating which chills the body. If wet, change into dry clothes. Keep informed of weather forecasts.

Excessive heat - prolonged periods of hot weather with temperatures in the 90s or above combined with high humidity can lead to lead to life-threatening conditions if safety rules are not followed. Excessive heat can lead to heat cramps, which are muscular pains and spasms, heat exhaustion, which is a form of mild shock, or heat stroke, in which case the body’s cooling system breaks down. Safety rules: Always drink plenty of water, regularly and often. Wear light weight, light colored clothing. Stay out of the sun and in a well ventilated shady area. Reserve strenuous activities for the coolest times of the day. Eat smaller meals, less protein, and snack more often.


2(b). What is the difference between a severe weather Watch and a Warning?
A Watch is a “maybe.” A Warning is a “yes, it will happen.” For a Watch, make plans for what safety actions you will take if a Warning is issued or if threatening weather approaches. For a Warning, you need to take action immediately to protect yourself and to help others get to safety.


4(a). What causes wind?
Wind is air in motion, or moving air. It takes energy to move things. And that energy is supplied by the sun. The sun heats the earth that heats the air next to the ground. Air that is heated becomes less dense and is pushed up or made buoyant by colder air that is more dense. Compare this to popcorn. Unpopped kernels are like bits of cold air. Popped kernels are like bits of warm air. A bag of partially popped corn kernels will have unpopped kernels that are more dense on the bottom and popped kernels, which are less dense, pushed to the top. The pushing caused by dense unpopped kernels against less dense popped kernels is the same kind of force that causes wind. So density differences between hot and cold air is what causes wind.


4(b). Why does it rain?
Raindrops are a liquid form of precipitation that are created by the collision of many droplets within clouds. Raindrops grow to become heavier than air and are pulled to the ground by earth’s gravity. In general, the bigger the cloud and the greater the amount of humid air moving up into the cloud, the heavier the rain will be.


4(c). How does lightning form?
Lightning is the static electrical discharge between positive and negative charges in and around a thunderstorm. Different kinds of particles within the cloud, ice crystals, hail, and water droplets carry different kinds of electrical charge. The concentration and separation of these different kinds of particles by strong updrafts and downdrafts within a thundercloud leads to large electrical differences from one part of the cloud to another and between the cloud and the ground. The differences become great enough to attract streams of charged particles that are drawn like magnets to the opposing charge. (These streams of charged particles are called leaders and streamers). Once the connection is made between concentrations of positively and negatively charged particles, the electrical discharge causes the bright flash that we call lightning.


4(d). How is hail formed?
Hail is a ball or chunk of ice that forms in the upper reaches of a thunderstorm. Water drops are carried aloft by updrafts within the cloud into air that is much colder than freezing. The drops freeze and begin to fall, but are caught by the updraft over and over again, each time collecting more water and refreezing and growing larger and larger. Eventually, they get thrown out of the updraft and fall toward the ground. In general, the stronger the updraft, the bigger the hail and the more intense the thunderstorm is apt to be.


4(e). What is the difference between high and low pressure systems in the atmosphere and how is this related to good and poor weather?
Pressure is the weight of the air above you. High pressure means that the column of air weighs more, and in low pressure, it weighs less. In areas of high pressure, dense air from above is moving down or sinking toward the earth. The air warms and dries as it sinks resulting in clear skies and fair weather. In areas of low pressure, lighter, less dense air from lower levels near the ground is moving up. The air cools as it rises and water vapor in the air begins to condense into liquid water droplets. The process of condensation leads to widespread cloudiness and precipitation within low pressure systems. The measurement of atmospheric pressure is one of the main ingredients used to predict the weather.


7. Define Acid Rain
Acid rain, more accurately known as acid deposition, begins with the burning of fossil fuels, such as coal, oil, or gas. The resulting air pollution contains sulphur and nitrogen, which combine with water and oxygen to form acidic compounds. These compounds can be carried by winds for hundreds of miles, and are deposited on the earth by settling (dry deposition), or through rain, snow or fog (wet deposition). As you can see, there are several ways for "acid rain" to reach the earth.


         Identify human activities which pollute the atmosphere
By far the most serious cause of acid rain is the burning of fossil fuels for energy, such as coal, oil, or gas. Many older electric utilities still rely on coal to produce electricity, and these produce an estimated 67 percent of the sulphur released into the atmosphere. Transportation (cars, trucks, motorcycles, and buses) produces an estimated 40 percent of the nitrogen released into the atmosphere. Other contributors include manufacturers and mills as well as other machines which use internal combustion engines, such as lawnmowers.


         What effects does this pollution have on people?
The most direct effect acid rain has on people involves respiratory problems in more sensitive people, such as children or people with asthma. Acid deposition also releases toxic metals from the soil, which can then get into drinking water supplies. There are also many indirect effects on humans resulting from environmental damage to plants and wildlife.


8(b). What type of weather is most dangerous or damaging in central North Carolina?
Lightning from thunderstorms is probably most dangerous or damaging because of how frequently it occurs and because of how much time we spend outdoors. On average in central North Carolina thunderstorms occur on about 45 days each year, most of the time in the warm weather season and late in the day when we may be taking part in outdoor recreational activities. About 73 people are killed by lightning each year in the United States and several hundred more people are injured. Lightning often causes fires or electrical damage in buildings that are struck and is responsible for starting most forest fires.


         How do people receive warnings for severe weather and floods?
For people outdoors, away from computers and televisions, battery operated NOAA weather radio is the best and most economical way to receive warnings. NOAA weather radios with the alarm feature can let you know immediately when a warning has been issued for your area.


In your home, on-line computers, commercial and cable TV, commercial radio, and even cell phones can be used to receive warnings.