Weather workshop wraps
By Eloise Aguiar
up with La Nina in
winter forecast
Star-BulletinLa Nina -- a condition of cold ocean temperature in the east-central Pacific -- will continue into next year and island residents can expect a wetter and cooler winter as a result, according to a National Weather Service meteorologist.
However, even with the prediction of higher than normal rain, some parts of the islands remain dry, said meteorologist Jim Weyman, in charge of the Honolulu Forecast Office.
For instance, windward areas have experienced a wetter climate, but leeward sites are seeing little change in conditions.
"The leeward side of the Big Island, the leeward side of Maui are still below normal precipitation," he said. "They are almost in a drought situation."
Despite recent heavy rains, Hawaii up until November has seen drier than normal weather, said Roy Matsuda, lead forecaster for the National Weather Service.
December has had a couple of storms but the total amount of rain for the first half of the month is still average, about 1.5 inches, Matsuda said.
"It has not been a wetter winter than usual, so far," he said, noting that La Nina existed last winter and Hawaii was dry. While the probability of rain is high, it is not certain, he said.
Under La Nina, the equatorial water temperature in the Pacific is 1 to 3 degrees colder than expected, Weyman said. He said the La Nina condition should last until spring or early summer.
The forecast was part of a workshop yesterday for meteorologists, emergency planners, researchers and others who help warn the public about floods and winter weather. Flash floods have caused 28 deaths in 28 years in Hawaii, Weyman said.
One of the goals of the workshop was to save lives. The Weather Service does this by collecting data from satellites and radar to make predictions. Information also is gathered by volunteers, who are recruited and trained by the National Weather Service Skywarn Program, Weyman said.
"We call them the eyes and ears of the National Weather Service," he said.
People of various backgrounds join Skywarn, but they all have an interest in weather, said Tom Heffner, the warning coordination meteorologist.
Nearly 350 Hawaii residents volunteer and their observations are critical for predicting floods, Heffner said.
Volunteers are given rain gauges to collect the necessary information. Among the volunteers are ham-radio operators who are used during storms to operate high-frequency radios at the Weather Service headquarters to collect data from other ham operators in the field.
"Skywarn volunteers have helped us in every flood event we've had this year," Heffner said.
New developments also help predict rainfall and possible flooding, said Steven Businger, a University of Hawaii professor and consultant for the Pacific Disaster Center.
Scientists have discovered, for instance, that signals from satellites are delayed because of humidity in the atmosphere, signaling a higher potential for rain.
Researchers also have found a correlation between lightning and rain.
"The more lightning the more rain," Businger said.
