NASA OBSERVATIONS IMPROVE HURRICANE FORECASTS
With hurricane season approaching, scientists find that NASA
observations can significantly improve predictions of both the
direction and strength of hurricanes.
Hurricane Erin moves up the U.S. East Coast on September 10,
Credit: NASA/SeaWiFS Project
Moisture measurements collected by a NASA Langley Research
Center instrument could improve computer-predicted estimates of a
hurricanes track by 100 kilometers (62 miles) and intensity
by 20-25 percent for three-day forecasts.
Scientists collected moisture measurements from the Lidar
Atmospheric Sensing Experiment (LASE) on a NASA DC-8 as the
aircraft flew over, through and around hurricanes during
NASAs fourth Convection And Moisture Experiment (CAMEX) in
A computer model, developed by the Florida State University
(FSU) in Tallahassee, generated predictions based on operational
satellite observations -- the same imagery we see in television
weather forecasts -- both with and without CAMEX-4 LASE data.
The scientists found the predictions that use LASE data provided
more accurate forecasts for CAMEX-4 hurricanes Erin, Humberto and
Gabrielle. In general LASE data improve the estimates of the
hurricanes tracks by 100 kilometers and intensities by 20-25
percent for three-day forecasts.
Research aircraft typically flew within the CAMEX-4 region of
interest, indicated with range
rings centered on the base of operations at Jacksonville Naval Air
Station (JAX NAS).
Credit: NASA CAMEX-4 Team
"Improving our forecast capability would significantly benefit
the financial security and public safety for the coastal regions of
the U.S. and, ultimately, over other coastal regions of the world
impacted by hurricanes and typhoons," said Edward Browell, the
principal investigator for the experiment. Browell and Langley
colleagues -- Syed Ismail and Rich Ferrar -- provided data on their
study in a paper published recently in Geophysical Research
Forecast models currently give a coastline region of about 700
kilometers (434 miles) indicating where a hurricane will first
approach land and, subsequently, where warnings and evacuation
orders will be given to residents.
"A 100-kilometer improvement in our ability to predict where a
hurricane will strike land will save an estimated 50 million
dollars in preparation and evacuation costs and increase public
confidence and response to hurricane forecasts," Ismail said.
Although not tested in real time, scientists also believe that
the FSU predictions using LASE data would have been more accurate
than other forecasts for the same hurricanes. The difference is due
in part to the FSU model including advanced capabilities for
simulating processes related to moisture and the transfer of energy
or heat in hurricanes. This study confirms the importance of
detailed moisture profiles, like those provided by LASE, for
"LASE helps define the energy source for hurricanes by better
understanding how much moisture is flowing into them," Browell
When water vapor releases heat or energy as it changes phases,
it channels energy into the atmosphere. If atmospheric conditions
are right, water vapor becomes the main energy source for hurricane
By better understanding the energy source of hurricanes,
researchers can more accurately predict how hurricanes will develop
and intensify and, perhaps most importantly, where they will
NASAs Earth Science Enterprise, charged with fulfilling
NASAs mission to understand and protect our home planet,
supported the work of the LASE team in CAMEX-4.
For more information: