California water planners hear NASA long-term forecast

Dec 10, 2013 by Carol Rasmussen
This image shows a dried watercourse near Dixon in California's Central Valley. Another dry winter is in the forecast for the state. Credit: UCAR

Recent NASA research tying California weather to large-scale atmospheric patterns contributed to the newly issued experimental Winter Outlook Forecast for Water Year 2014 by the California Department of Water Resources (DWR). That forecast, calling for continued dry conditions for the third year in a row, was the first to include discussion of climate research from NASA's Jet Propulsion Laboratory, Pasadena, Calif.

JPL researchers have found a correlation between variations in California winter precipitation and a large-scale tropical weather pattern called the Madden-Julian Oscillation (MJO). Each oscillation event consists of recurring periods of storminess on a very large scale, 3,000 to 6,000 miles (5,000 to 10,000 kilometers), which travel eastward from the Indian Ocean across the Pacific. These events last about 50 days but do not recur regularly.

"When an MJO happens, California rainfall and snowfall increase and decrease during specific parts of its life cycle," said Duane Waliser, chief scientist of JPL's Earth Science and Technology Directorate. Waliser presented the research findings at the workshop where the DWR's water was prepared.

"The MJO gives us a window of opportunity to forecast tendencies for more rain or dry weather three or four weeks in advance—much longer than a standard ," Waliser said.

A separate JPL study presented at the workshop has shown that atmospheric river storms are also influenced by large-scale atmospheric patterns. The forecast calls these storms the "wild card" in the state's water outlook, because just two or three such storms can produce as much precipitation as the state usually gets in an entire year.

Explore further: The tsunami-early warning system for the Indian Ocean – ten years later

add to favorites email to friend print save as pdf

Related Stories

Improved climate forecasts sought out by new report

Sep 10, 2010

From farmers to government officials in charge of efficiently managing Earth's precious water and energy resources, people all over the world rely on accurate short-term climate forecasts on timescales ranging ...

Study finds climate link to atmospheric-river storms

Nov 11, 2013

(Phys.org) —A new NASA-led study of atmospheric-river storms from the Pacific Ocean may help scientists better predict major winter snowfalls that hit West Coast mountains and lead to heavy spring runoff ...

US forecast: Hot, dry weather to linger

Jul 19, 2012

(AP) — U.S. government weather forecasters predict the unusually hot dry weather that has gripped much of the nation will linger into autumn, especially for the parched Midwest heartland.

Mastering the mysteries of the Madden-Julian Oscillation

Sep 13, 2011

Tropical monsoons, cyclones and thunderstorms. Weather patterns around the world are influenced by the MJO. And now, climate scientists can model it, thanks to research from Pacific Northwest National Laboratory ...

Recommended for you

Scientists make strides in tsunami warning since 2004

17 hours ago

The 2004 tsunami led to greater global cooperation and improved techniques for detecting waves that could reach faraway shores, even though scientists still cannot predict when an earthquake will strike.

Trade winds ventilate the tropical oceans

18 hours ago

Long-term observations indicate that the oxygen minimum zones in the tropical oceans have expanded in recent decades. The reason is still unknown. Now scientists at the GEOMAR Helmholtz Centre for Ocean Research ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.