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NOAA Magazine || NOAA Home Page NOAA's FIELD STUDY TARGETS WEST COAST STORMS
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." "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. 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. 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. Relevant Web Sites
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