Wet Winter Ahead
For Pacific Northwest In
Repeat Of Last Year
Says JPL
By Andrew Bridges
Chief Pasadena Correspondent
New images from a United States-French weather satellite show this winter will likely be a repeat of last year's La Nina conditions, with drier-than-normal weather in the American Southwest and unusually wet weather in the Pacific Northwest.
The TOPEX/Poseidon image, containing data gathered between October 5-15 and released Wednesday, shows a massing of cooler-than-normal water in the equatorial Pacific Ocean. The phenomenon, known as La Nina, is the flip-flop of its warm-water cousin El Nino.
Bill Patzert, an oceanographer at NASA's Jet Propulsion Laboratory in Pasadena, California said the new image shows a weak to moderate La Nina situation coming back after a summer spent in "hibernation."
"The jet stream is going to be fueled up in the western Pacific, so from San Francisco north, it's going to be déjà vu all over again, to quote Yogi Berra," Patzert said. "It's going to be pretty stormy in the Pacific Northwest and dry in Southern California."
For the 12 months that ended June 30, 1999, Southern California received about half as much rainfall as it does on average. In the Pacific Northwest, however, La Nina brought on record amounts of precipitation.
At the Mt. Baker Ski Area in Washington, 95 feet (29 meters) of snow fell, setting a new world record.
"We had to close for two days at the end of February to dig the chairlifts out," said Patrick Renau, operations manager for the ski resort. "We had to make ditches to get the lifts through, otherwise you would sit in the chairs and your feet would drag in the snow."
Vernon Kousky, a research meteorologist with the Climate Prediction Center in Washington, D.C. said weather models, which include TOPEX/Poseidon data, indicate La Nina's effects probably will not be as severe.
"We're also anticipating a lot of variability in this year's pattern, but no where near the persistence of last year's pattern," Kousky said.
TOPEX/Poseidon, launched in August 1992 and managed by JPL, measures global sea levels every 10 days with unprecedented accuracy.
Sea height in turn gives an indication of the ocean water's temperature, with warmer water generally higher than cooler. In the satellite image, cooler waters are blue to purple, indicating they are about 6 inches (14 centimeters) lower than normal. Warmer are red to white, indicating they are about 8 inches (20 centimeters) higher than normal. Normal ocean heights are shown as green.
Patzert said the satellite images are a reminder of the often not-too-delicate relationship between the Earth's oceans and its atmosphere.
"The ocean is like an elephant, and the atmosphere a ballerina," Patzert said. "And every fall, the atmosphere waits to hear from the elephant what to do."