NOVA Online (click here for NOVA home)
Tracking El Niño Site Map El Niño Scorecard
by Mark Hoover

The great 1997 El Niño snuck up on us. Once here, it seemed to spawn an entire industry last year, the business of El Niño forecasting. We kept track of some of the major predictions, matched them up with what actually happened, and tabbed the results to get a sense of just how good the forecasters have gotten.

California | Northern US and Canada | Peru | Australia | India and Oceania | Africa | Eastern Pacific and Western Atlantic

Date of Appearance
Prediction: Before El Niño actually showed up, many forecasts said 1997 might be an El Niño year; many said not. It wasn't until late February or March that scientists put the pieces of the puzzle together and realized El Niño was underway. As NOAA's Michael Glantz wryly put it, "once it was started, it wasn't as hard to predict."

Outcome: The ayes had it. But no one predicted it would be a record-breaker; most thought it would be weak and short-lived.

Prediction: In early autumn last year Ants Leetmaa, the director of NOAA's National Center for Environmental Prediction, warned Californians of a long winter of powerful storms comparable to the devastating storms in the El Niño winter of 1982-83. Specifically, he said "The southern part of the state can expect rainfall on the order of 200% of normal."

Outcome: El Niño deflected the two major northern jetstreams so that they carried a long train of storm systems into the state throughout the winter. Southern California got double its average winter rainfall, recording approximately 230% of normal. Flooding was widespread in several coastal areas, with regions near San Francisco suffering especially.

The Northern US and Canada
Prediction: The northern half of the US was predicted to experience a relatively mild winter, as the jetstream could be expected to park itself farther north than usual, acting as a barrier against cold Canadian air. However, especially along the east coast, intrusions of southern moisture might lead to more rain and storms than usual.

Outcome: The northern US generally enjoyed a mild winter. One way to measure is the total expenditure on heating fuels; the average heating bill over the winter was as much as 10 percent lower than normal.

Prediction: Peru would be inundated by heavy rains throughout the peak of the El Niño occurrence, and cooler waters off the coast would mean a drop in fish catch.

Outcome: Peru and adjacent Ecuador suffered massive flooding, with rains rarely stopping for months on end. In January and February, the land could absorb no more water, and vast new lakes—some 50 miles long—appeared in formerly dry coastal areas. Rivers ripped out entire towns in the mountains, and completely inundated agricultural areas in valleys. At sea, fish stocks were depressed, and many fishermen suffered severe economic pain.

Prediction: Australia would wither under an extended drought throughout the northern winter (which in Australia and the Southern Hemisphere is summer).

Outcome: This one's a toss-up; as NOAA's Mickey Glantz put it, "the (forecasting) operation was a success, but the patient died." Meteorologically speaking, there was a bad drought, as rainfall totals across Australia were well below normal. But agriculturally speaking, enough rain fell at just the right times to prevent catastrophic wheat crop and cattle losses. Australian newspapers gave thanks to "Billion-Dollar Rains" that appeared just as disaster seemed imminent, showing that it's not how much rain you get, but when you get it, that counts.

India and Oceania
Prediction: India and Oceania would suffer a failure of vital monsoons (heavy seasonal rains).

Outcome: The monsoons had a late onset, showing up many weeks later than normal, but although erratic in schedule, were in no sense "failed." Indonesia in particular suffered a self-inflicted wound, as fires deliberately set to clear forest lands for slash-and-burn agriculture raged out of control when the monsoons took their time arriving. Fears of imminent famine and misery in India disappeared with the onset of the life-giving rains, although coastal China was flooded and battered by an excess of violent storms bearing tornadoes and high winds.

Prediction: Southern Africa would suffer drought and severe food shortages, followed by increases in disease.

Outcome: There was very little noticed effect on weather, no major drought, and no widespread outbreaks of disease or famine.

Eastern Pacific/Western Atlantic
Prediction: The Eastern Pacific would engender some very powerful hurricanes, while Atlantic hurricane production would be suppressed.

Outcome: Some of the most powerful hurricanes ever measured spun up in the Pacific, including Hurricane Linda, so powerful that weather scientists proposed a new "Category 6" (the current system only goes up to 5) to describe it. (Compare Linda, with winds of 185 mph, to Andrew, the hurricane that devastated Homestead, Florida in 1994 with winds of 130 mph.) Meanwhile, the Atlantic hurricane season was below normal.

Anatomy of El Niño | Chasing El Niño | El Niño's Reach
Dispatches | Resources | Mail | Site Map | El Niño Home

Editor's Picks | Previous Sites | Join Us/E-mail | TV/Web Schedule
About NOVA | Teachers | Site Map | Shop | Jobs | Search | To print
PBS Online | NOVA Online | WGBH

© | Updated November 2000