Answers to Weather Questions

• Why is the sky blue? Air molecules preferentially scatter blue and violet light, allowing the other colors of light from the Sun to pass through the atmosphere to the surface.
• What makes the wind? Pressure differences between areas of high and low pressure, ultimately driven by the uneven heating of the Earth's surface by the Sun.
• What are clouds made out of? Clouds are made of tiny drops of water. High in the sky, the air is very cool. This coolness changes the water vapor in the air into very small drops of water -or even into crystals of ice! These water drops or ice crystals float together as clouds.
• Do all clouds make rain? No, they don't. Some clouds show that nice weather is here. Others bring storms. You can learn to tell them apart. High, white, wispy clouds often come with good weather. Some clouds are puffy, like giant balls of cotton. They are usually a sign of nice weather-but not always. Low clouds that look like flat gray sheets bring rain and drizzle.
• What does a thunderstorm cloud look like? A thick, puffy cloud that is dark gray means that rain, thunder, and lightning are on their way.
• Why does it rain? It rains because the water drops in a cloud get too heavy to keep floating in the air. As the tiny drops of water inside a cloud bum into each other, they stick together and get bigger and heavier. When the drops are big enough, they fall as rain.
• What is fog? Fog is a cloud that forms next to the ground. When warm air near the ground cools off, the water vapor in the air turns into tiny drops that we see as fog. Fog often appears late at night because the ground stays warm but the air cools off.
• What is hail? Hailstones are balls of ice that fall during thunderstorms. Inside a cloud, air moves up and down. It carries drops of water up high where it is very cold. The drops freeze into bits of ice. When they start to fall, a little water sticks to them and freezes. Sometimes the bits of ice keep going up and down on th4 streams of air. They get a bit bigger each time they freeze. Finally they fall as hail. Hail the size of golf balls is common.
• Can hail be as big as a softball? Absolutely ... even bigger!
• What is snow? Snow forms high in the clouds where it is very cold. First, water drops freeze to make tiny crystals of ice. Then more water drops stick to the crystals and freeze. The crystals get bigger and bigger. When they are heavy, they fall to the ground as snowflakes.
• How big are the largest snowflakes? They are about as wide as a penny.
• Is it true that all snowflakes have six sides? Yes!
• Why can I see my breath on a cold day? When you breathe in on a winter's day, the air is very cold. But your body warms it up and adds lots of water vapor. When you breathe out, your breath cools and the water vapor turns to droplets. Each breath you let out is like a little cloud of fog.
• What is lightning? Lightning is a giant spark of electricity. We often see if flash across the sky during big thunderstorms. Inside a thunder head, air rushes up and down. Bits of ice and water bump into each other. That makes electricity build up in different parts of the cloud. When there's too much of it, we see a FLASH of lightning.
• Can lightning strike twice in the same place? Yes. One famous example is New York's Empire State Building, which was hit by lightning several times during the same storm.
• Why does thunder come after lightning? Thunder is the noise that lightning makes. A flash of lightning heats the air around it. Then the air moves outward quickly, making the sound of thunder. We see lightning the instant it lights up the sky. But the sound of thunder moves more slowly through the air. So it always comes after we see the lightning.
• Do hurricanes spin in different directions in the northern and southern hemispheres? Yes. Counterclockwise in the north, and clockwise in the south.
• Which is bigger - a hurricane or a tornado? A hurricane like Floyd (1999) may be as big as the State of Texas: clusters of thunderstorms may cover lots of territory but any one storm is much smaller than a hurricane. Tornadoes are smaller still, from 50 meters or so up to a mile.
• What weather event kills the most people in an average year? Surprisingly, the answer is extreme heat and cold, followed by flooding.
• What extreme weather event is the most expensive on average? Hurricanes cause the most damage and cost the most money, but fewer people die in hurricanes than in tornados, floods or lightning in an average year.
• Can a groundhog predict the weather? Sorry, they can't!...but it is a fun tradition!
• We can predict the weather-- can we predict the climate? NOAA successfully predicted the 1997-98 El Nino event.
• Do tornados only happen in the spring and summer? No! While most tornados occur in the spring and summer, they can happen any time and have occurred in every state in the contiguous United States.
• Do tornados spin clockwise? Tornados can spin clockwise or counter-clockwise.
• Is lighting always accompanied by thunderstorms? Yes. Thunder is the noise that lightning makes
• What time of the day do thunderstorms usually occur? In the late afternoon and evening.
• What is almost always accompanied by thunderstorms? Lightning, hail, and wind.
• How long do thunderstorms last? Usually 20-30 minutes.
• What was the latest hurricane to hit the United States? Hurricane Floyd in 1999
• How many categories are there to describe the intensity of hurricanes? Five
• What's the safest place to be during a tornado? In the inside room of a building - at home a closet or bathroom.
• If you are caught outside during a thunderstorm and can't get to a building or a house what should you do? Find a low-lying place, such as a ditch or culvert, crouch with only your feet touching the ground, cover your head. Don't stand under a large tree!
• During a thunderstorm, is it okay to talk on the phone, take a bath, or use electrical appliances? No! The electricity and travel through them. People have been known to die while talking on the phone during a thunderstorm.
• During a flash flood, it's a good idea to drive through shallow water to get to safer ground or to your home. NO! It only takes six inches of water for a person to lose control of their vehicles. Never go through water. It's impossible to tell how deep the water really is and the power of the water is deceptively powerful. More than half of the deaths from flash floods - about 100 a year - are people who are trapped in vehicles while attempting to cross low water crossings.
• What states have the most tornados?
• Which state/s is prone to the most weather-related hazards?
• How does a Doppler Radar help weather forecasters detect thunderstorms?
• What is a down burst ?
• What does a barometer measure?
• Which area of the U.S. is most susceptible to natural disaster?
• What's the most costliest weather-related natural disaster the U.S. has experienced? Hurricane Andrew in 1993, which caused at least $30 B in damages
• How many weather forecast offices does the National Weather Service have? 121
• What should you do if you hear a tornado warning?
• What should you do if you hear a flash flood warning?
• What should you do if you hear a thunderstorm warning?
• If you hear lightning, but there is no rain and you see no lighting, are you safe to stay outside?
• What are the two major weather-related disasters that happened in 1999? The Oklahoma Tornados (48 deaths and $$) and Hurricane Floyd (68 deaths and $$)
• Where is the National Hurricane Center located? Miami, Florida
• What's the difference between a flash flood and a river flood?
• How many days a year are Weather Forecast Offices open? 365-24 hours a day!
• What is a tsunami? It's a tidal wave caused by either an earthquake or a volcanic eruption.
• Does lightning kill only a couple of people a year? No! It kills about 60 people and injures many more.
• Which country on earth has the most diverse weather? The United States