Weird Weather is Really Normal!
1992 was one of the coolest in the U.S. for the past 100 years. But the winter that preceded it was the warmest. Heavy rains in February flooded California. Before that, the state had been in a six-year-long drought. A lot of people are wondering if something is wrong with our weather.
"We don't call what is happening weird weather," said Lee Grenci (GREN-see), a weather expert at Pennsylvania State University. "There are always natural changes in our weather."
A World of WeatherHeat from the sun, winds swirling around the globe, the world's oceans, and many other factors help create Earth's weather.
"We understand how the weather works," said Pat Kennedy, a weather expert from the Center for Atmospheric Research. "But the world is just so big. It is hard to know what kind of weather is going to happen in any one spot."
Kennedy said some things happened recently that probably changed the weather. One was the eruption of Mount Pinatubo (pin-ah-TOO-bo), a volcano in the Philippines.
In June, 1991, the volcano shot tons of dust into our atmosphere. Weather experts say the dust may be blocking some heat from the sun so it cannot reach Earth. That may have helped cause a cool summer.
So why did the winter set a record for warmth? It may have been El Niño (NEEN-yo), a big pool of warm water that formed in the Pacific Ocean last winter. The warming effect of El Niño may have been more powerful than the cooling effects of the volcano.
Weather WarmerEl Niño happens once every four to ten winters. Winds blowing from the northeast push lots of warm Pacific Ocean water together. When the strong winds stop blowing, the big pool of warm water starts to drift east. This is El Niño.
El Niño pushed warm, wet air toward the U.S. This may have helped cause heavy rains in California. It may also have made the winter weather too warm for much snow to fall in some northern states. Grenci said the El Niño affected our weather until March, when it cooled off.
Too Much Pollution?James Hansen, another weather expert, says pollution in our atmosphere is holding in Earth's heat. This is called the greenhouse effect. Hansen blames the greenhouse effect for a slight increase of the world's temperature over the last 100 years. But not all scientists agree that the greenhouse effect is changing our weather.
So what is our winter forecast?
"In September, they had more snow than usual in Fairbanks, Alaska. That gives me this feeling that we may have a lot of snow this year," Grenci said. "But it is just a feeling. There's no way to know for sure."
December 11, 1992