It's Raining Fish and Spiders (35 page)

A rainbow is an optical illusion whose apparent position in the sky depends on the observer's location. You can make a rainbow at home with the garden sprinkler; just make sure you make the drops very small or a mist.

Eyes on the Skies!

The question I am asked the most has to be, “How do you know it's going to rain?” It's a great question with an easy answer!

I have two wonderful tools: Weather satellites in outer space and Doppler radars on the ground are our eyes on the skies.

The first weather satellite was launched on April 1, 1960 (that's right, April Fool's Day, but this was no joke!). Its name was TIROS-I. Compared to today's satellites, it was pretty crude, equipped with what amounted to a Brownie camera and an AM transmitter! But TIROS-I represented the dawn of a new era. For the first time, meteorologists could see pictures of a storm over the northeastern United States.

NASA

Nowadays, satellites carry instruments, not cameras, that scan the Earth to form images. Geostationary Operational Environmental Satellites (GOES) circle the Earth at a very high altitude of 22,500 miles in what's called a
geostationary
orbit. That means they always stay above the same part of the Earth's surface, for instance observing the Northern Hemisphere. The instruments on these satellites detect and measure the Earth's emitted radiation, from which atmospheric temperature, wind direction and speed, moisture, and cloud cover can be derived. GOES data are used to generate the satellite animations that you see on television. The first geostationary satellite (GOES-1) was launched on October 16, 1975, and quickly became a critical part of our weather forecasting.

Polar Operational Environmental Satellites (POES) operate on polar orbits at a low altitude of about 500 miles high near the North and South poles. The polar orbit allows the satellite to provide complete coverage of the Earth as the planet turns beneath the satellite. TRIOS-I was a POES satellite.

NASA

My second most important tool is Doppler radar. Radar is an acronym for
radio detection and ranging
. Christian Andreas Doppler was an Austrian physicist who, in 1842, first described how the observed frequency of light and sound waves was affected by the relative motion of the source and the detector. This phenomenon became known as the
Doppler effect.

A radar antenna sends out short, high-powered bursts of radio wave energy of approximately 1,000 pulses per second. Radar uses radio waves at the very high end of the radio spectrum. After each pulse, the radar listens for a signal reflected back from the cloud. When the pulse hits any precipitation—rain, snow, or ice—the energy of the pulse is scattered, so only a small part of the signal returns to the antenna.

The radar measures the strength of the received signal and how long it takes to return from the cloud, which tells meteorologists how far away the precipitation is. This area of the radar is called
base reflectivity.
Doppler radar can tell you how hard the rain, snow, or ice is falling, as well as its position and height. Precipitation images are updated every 4 to 6 minutes.

Weather radar systems use colors to indicate the intensity of precipitation. Light blues indicate light rain and the colors go up from shades of blues to yellows to reds as the rain or snow grows stronger and denser. If you see red on a Doppler radar, you need to find a safe shelter!

You're a Big Windbag!

The other beautiful feature of Doppler radar is that it can see turbulence. The vertical velocity feature of the radar allows us to pick out areas of a thunderstorm where violent, rotating winds may indicate that a tornado's funnel cloud might be forming.

This happened to me just a few years ago while I was doing the weather live on-air. I suddenly saw, in a line of thunderstorms I was showing, a little group of colors that represented a comma or hook shape. I immediately knew it was a funnel cloud. The shape was moving from Staten Island across New York Harbor toward Brooklyn. I warned Brooklyn residents to not go outside as they might encounter a tornado. Luckily, no one was injured, but an EF1 tornado touched down several times and caused a lot of damage to brownstone buildings and town houses, and knocked over trees.

Who Thought Up the Word
Meteorologist
?

The Greek philosopher Aristotle is one of my heroes. He is credited with discovering many scientific things. For me personally, his greatest discovery is what he termed
Meteorologica
, the first major study of the atmosphere. From Aristotle's work came the term
meteorologist
, meaning a person who studies the atmosphere.

I honestly believe that I have never worked a day in my life. Each day I wake, I can't wait to take a look at the weather. I look forward to going to the weather office every day, even when I get the forecast wrong! That's the beauty of weather forecasting: when you make a forecast and the next day the weather looks nothing like what you forecasted, then you know exactly what you did wrong!

I even look at the weather when I'm not going to the office. So I guess it's true that if you love what you do for a living, you will have never worked a day in your life, because it's not work, it's a pleasure.

I have lots of weather jobs. I do the weather on TV, digital cable, radio, and the Web. I teach meteorology as well. It's weather, weather, weather, all the time! I love it!

Performing the weather on television is fun, but it carries with it a big responsibility. I know that some people think weathermen are only good for telling you whether or not you need to wear a coat or carry an umbrella, but forecasting means much more than that.

It is my job to inform you and all my viewers and listeners about what type of weather to expect, and if there is going to be any dangerous or life-threatening weather nearby. I view the meteorologist's role as that of a public servant. I help people plan their days when things are normal and let them know if they need to take drastic measures such as evacuating from their home, school, or workplace. Accurate forecasts help people at times of crisis, but also in their everyday lives.

I love helping people—and sometimes people ask for my help with the most interesting things! Once a lady called me and said she wanted me to come to her home and take a look at a meteor that had crashed through the trunk of her car. I tried to explain to her that was work for an astronomer and she began yelling at me, “But you call yourself a ‘
me-te-or
-ol-o-gist!'”

The most interesting part of my job is going on camera. When you see a meteorologist doing the weather on TV, he or she is not standing in front of a real weather map. The meteorologist is standing in front of a blue or green wall. In weather reporting, we use a technique called
chroma key.

Steve Fenn; used by permission.

Chroma key allows us to mix two images together by removing a specific color from one image, revealing the second image behind the first. Blue and green are used most often because they are the least like skin tone. Sometimes when blue is used, people's shirts and ties disappear! They look pretty funny with the weather maps right under their chins. For this reason, the wall behind me on the WABC-TV set is bright green.

Steve Fenn; used by permission.

The weather computer, video, still pictures, and any other images we are going to use are all keyed to that shade of green. Once on Halloween, I wore a green bodysuit that covered everything except my face. I was completely invisible! I looked like a floating head! This is the same technique used in movies to make characters look invisible or to place them in fantastic, computer-created settings.

What is often called
bluescreen technology
was invented in 1940 by Larry Butler. One of the first movies to use bluescreen technology was 1958's
The Old Man and the Sea
, starring Spencer Tracy.

Steve Fenn; used by permission.

I Know the Story: You Walked to School Every Day, Uphill Both Ways, in the Snow!

When I started in TV, the weather computer hadn't been invented yet. I did the weather standing in front of physical maps. The weather symbols I used were either magnets or pieces of thin, soft plastic, which I wetted and stuck to the map. Once, during a live weathercast, someone turned on a fan in the studio and blew all my symbols off the map!

Some weathercasters would use a marker to draw the fronts and symbols right onto the map or onto a piece of glass that had the map drawn on it. These guys were so good they could stand behind the glass and draw the weather systems backward! When you watched them, it looked completely normal because they were so comfortable working backward!

Computerized weather graphics came along in the 1970s and revolutionized the way the weather was presented. Weathercasters could now show radar and satellite pictures, animated loops, weather maps, temperature charts, and even graphics that explained the weather. It was a very exciting time! Now we could actually show what the weather was doing! We could also show what we expected the weather to do. Everything was easier—it was easier for us to explain the weather and easier for viewers to understand what was going on.