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NOAA's FIELD STUDY TARGETS WEST COAST STORMS

February 13, 2002 — Government and university scientists and forecasters are working together to improve forecasts of Pacific storms hitting the West Coast this winter. Their efforts include flying into almost a dozen storms to collect data on the damaging winter weather that typically strikes the West Coast, according to NOAA. (Click NOAA image for larger view of Dr. Clark King, of NOAA's Environmental Technology Laboratory, releasing a weather balloon into a storm in Bodega Bay, Calif.)

The project, the Pacific Land-falling Jets Experiment or PACJET-2002, is the third in a series of collaborative field experiments that concentrate on improving short-term forecasts of the heavy rain, snow and wind that hit the U.S. West Coast each winter. The experiment, which began February 1, builds on the two previous field experiments, CALJET in 1997/98 and PACJET in 2001, which also addressed priorities of the U.S. Weather Research Program concerning precipitation studies and identifying key observations needed for these predictions. As in earlier years, researchers will focus on both research and direct operational applications. This year, the aircraft part of the experiment will be based in Portland, Ore. It will end March 2.

"We are continuing to study the ‘low-level jet,' a fast moving current of air centered at around 3,000 feet, that occurs near cold fronts in winter storms," says F. Martin Ralph, PACJET chief scientist, of NOAA's Environmental Technology Laboratory in Boulder, Colo. "These land-falling winter storms can cause extreme coastal rains and extensive damage due to the high winds and heavy rain produced during the short period of time when they come ashore."

In addition to studying the low-level winds, the researchers will also be validating satellite data from NASA's QuickScat satellite. The data needed for extending the surface satellite measurements to the higher altitudes will also be collected.

"The science objectives this year are focused more on validation of the satellite data. We'll be looking at the low level winds from the NASA Quickscat satellite and also obtain some information on the strong wind regions," says the project's aircraft leader, Ola Persson, from NOAA's ETL.

PACJET-2002 will use a variety of special observing systems to augment existing operational systems. While NOAA has a broad network of weather radars, weather balloons, advanced satellites and surface observing systems across the United States, many of these systems do not cover the Pacific Ocean, which is an area that strongly influences weather across the country. "The flights over the ocean fill in some of the gaps in our knowledge and provide us with important data," says Persson.

NOAA's WP-3D Orion "hurricane hunter" aircraft will be equipped with special meteorological instrumentation, such as Doppler radar, dropsondes (which take meteorological measurements as they are dropped from the aircraft), NOAA's National Environmental Satellite, Data, and Information Service scatterometers, and in-situ meteorological and oceanic probes. The WP-3D Orion is a valuable resource for researchers since it can fly at a variety of altitudes and provides observational coverage at levels critical for defining weather systems. The crew includes NOAA Corps officers and civilian flight and electronic engineers and meteorologists from NOAA's Aircraft Operations Center in Tampa, Fla.

Persson says that during the experiment, they'll take the plane down as low as possible, possibly around 200 feet, to measure the winds. "We want to be out there when the satellite passes over, so our flights will be taking off between 1 a.m. and 3 a.m. in the morning or 1 p.m and 3 p.m. in the afternoon," he continued. The researchers will also be able to download radar images to weather forecast offices several times during the flight.

PACJET-2002 will incorporate ground-based, aircraft, modeling and satellite activities. NOAA's GOES satellite will be used in a new way to observe winds by tracking clouds that move with the wind. The new data, provided by NOAA and the University of Wisconsin's CIMSS, as part of the GWINDEX experiment, will also help fill data gaps over the ocean.

Eleven wind profilers—Doppler radar that measures upper-level winds and temperature—will be deployed at various locations along the coast from Southern California to Washington State. NOAA's Forecast Systems Laboratory will be running a high-resolution weather model, the Rapid Update Cycle (RUC), and distributing it to NOAA's National Weather Service Western Region for dissemination to local forecast offices. The RUC will also be used to assess the value of the new GOES winds for numerical weather prediction. The land-based instruments will be used both for operational purposes and for revealing the evolution of the frontal systems as they make landfall.

According to Bill Schneider, Science and Operations Officer for the National Weather Service in Portland, Ore., "This year's PACJET provides a great opportunity for the researchers at NOAA, NASA and the university community to work directly with our forecasters. Both groups benefit from the exchange of ideas and from the data gathered during the project."

Schneider says that the Portland, Ore., weather forecast office will provide daily weather briefings and access to the NOAA's sophisticated weather data and forecasting computers, known as AWIPS. "We also hope to utilize methods of communicating real-time data from the NOAA P-3 back to the NWS forecast offices, capabilities that we demonstrated during last year's PACJET project. NWS forecasters will also be part of the science crew aboard the NOAA P-3 during the project. And, real time weather discussions from aboard the aircraft may be relayed directly to forecasters in Portland and other NWS offices," he says.
Schneider hopes that new equipment and technology developed by the project's research groups will be integrated into daily forecast operations. "By providing very specific feedback to the research community, we see a better end product which our forecasters can use to improve the forecast people use every day."

Relevant Web Sites
NOAA's PACJET-2002 Field Activities

NOAA's Environmental Technology Laboratory

NOAA Research

NOAA's Data for Bodega Bay, Calif.

Media Contact:
Barbara McGehan, NOAA Research, (303) 497-6288

 

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