Steve Cole
Headquarters, Washington
202-358-0918
stephen.e.cole@nasa.gov

David Hosansky
National Center for Atmospheric Research, Boulder, Colo.
303-497-8611
hosansky@ucar.edu


RELEASE: 12-427

NEW NASA-FUNDED FORECAST SYSTEM HELPS TRANSOCEANIC FLIGHTS AVOID STORMS

WASHINGTON -- A new NASA-funded prototype system developed by the
National Center for Atmospheric Research (NCAR) of Boulder, Colo.,
now is providing weather forecasts that can help flights avoid major
storms as they travel over remote ocean regions. The eight-hour
forecasts of potentially dangerous atmospheric conditions are
designed for pilots, air traffic controllers and others involved in
transoceanic flights.

The NCAR-based system combines satellite data and computer weather
models to produce maps of storms over much of the world's oceans. The
system is based on products that NCAR has developed to alert pilots
and air traffic controllers about storms and related hazards, such as
turbulence and lightning, over the continental United States.
Development of the forecasts was spurred in part by the 2009 crash of
Air France Flight 447, which encountered a complex of thunderstorms
over the Atlantic Ocean.

The system was funded by NASA's Applied Sciences Program, which
supports efforts to discover and demonstrate innovative and practical
uses of NASA Earth science and satellite observations. NCAR worked
with the Massachusetts Institute of Technology's Lincoln Laboratory,
the Naval Research Laboratory, and the University of
Wisconsin-Madison to create the system.

"These new forecasts can help fill an important gap in our aviation
system," said NCAR's Cathy Kessinger, lead researcher on the project.
"Pilots have had limited information about atmospheric conditions as
they fly over the ocean, where conditions can be severe. By providing
them with a picture of where significant storms will be during an
eight-hour period, the system can contribute to both the safety and
comfort of passengers on flights."

The forecasts, which continue to be tested and modified, cover most of
the Atlantic and Pacific oceans, where NCAR has real-time access to
geostationary satellite data. The forecasts are updated every three
hours.

Pilots of transoceanic flights currently get preflight briefings and,
in certain cases involving especially intense storms, in-flight
weather updates every four hours. They also have onboard radar, but
that information is of limited value for strategic flight planning
while en route.
"Turbulence is the leading cause of injuries in commercial aviation,"
said John Haynes, Applied Sciences Program manager at NASA
Headquarters in Washington. "This prototype system is of crucial
importance to pilots and is another demonstration of the practical
benefit of NASA's Earth observations."

Pinpointing turbulence associated with storms over the oceans is far
more challenging than it is over land because geostationary
satellites, unlike ground-based radar, cannot see within the clouds.
Thunderstorms may develop quickly and move rapidly, rendering the
briefings and weather updates obsolete. Onboard radars lack the power
to see long distances or through dense clouds.

As a result, pilots often must choose between detouring hundreds of
miles around potentially stormy areas or flying directly through a
region that may or may not contain intense weather. Storms may be
associated with hazardous windshear and icing conditions in addition
to lightning, hail and potentially severe turbulence.

To create the forecasts, Kessinger and her colleagues first turned to
geostationary satellite measurements to identify regions of the
atmosphere that met two conditions: particularly high cloud tops and
water vapor at high altitudes. These two conditions are a sign of
powerful storms and strong updrafts that can buffet an aircraft. The
scientists next used fuzzy logic and data fusion techniques to home
in on storms of particular concern, and applied object tracking
techniques and simulations of wind fields to predict storm locations
at hourly intervals out to eight hours.

Researchers verified the forecasts using a variety of data from NASA
Earth observations, including the Tropical Rainfall Measuring Mission
(TRMM) satellite.

"These advanced techniques enable us to inform pilots about the
potential for violent downdrafts and turbulence, even over the middle
of the ocean where we don't have land-based radar or other tools to
observe storms in detail," Kessinger said.

The forecasts can be viewed at:


http://go.nasa.gov/W0doRu

For more information about NASA and agency programs, visit:


http://www.nasa.gov