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NSF PR 97-3 - January 16, 1997
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Scientists probe Connections between Coast-to-Coast
and Atlantic Ocean Winter Storms
Better Weather Forecasts, Understanding
of Climate to Result
Powerful winter storms that strike the U.S. West Coast
often occur in series, like the ones that recently
raked Washington, Oregon, and California. These storms
have their counterparts in the North Atlantic Ocean,
and scientists supported in part by the National Science
Foundation (NSF) are hot on their trail.
A major field program involving atmospheric researchers
from 11 countries is straddling the Atlantic Ocean
from Newfoundland to Ireland to study fierce winter
storms that move eastward across the ocean and pound
western Europe. Participating scientists include researchers
from the National Center for Atmospheric Research
(NCAR) in Boulder, Colorado. The project is called
the Fronts and Atlantic Storm Track Experiment
(FASTEX). Operations began on January 6 and will continue
through February.
"The findings should lead to better forecasts for
the west coasts of both Europe and North America,
as well as a better understanding of how oceanic winter
storms affect world climate," says Steve Nelson, program
director in NSF's division of atmospheric sciences.
Forecasting the development of oceanic storms is still
a challenge, largely because there are fewer weather
observations at sea than over land. Cyclones (low-pressure
centers) tend to develop along slow-moving cold fronts
that extend across the Atlantic. The cyclones often
develop midway between North America and Europe and
reach their peak strength a day or two later near
the British Isles.
FASTEX researchers are hoping to identify precursors
that may trigger cyclones once the precursors overtake
the cold front. These precursors could include jet
streaks (regions of higher wind speed inside the jet
stream) and pockets of air that descend from the stratosphere.
If such precursors can be located as they reach the
North Atlantic, the cyclones they later generate might
be better forecast up to two or three days in advance.
To follow the life cycles of precursors and cyclones,
a wide array of observational tools will stretch from
continent to continent and extend from midlatitudes
to polar regions.
Although the geography of the Pacific Ocean differs
from that of the Atlantic, some insights from FASTEX
will be applicable to both. For instance, precursors
beginning over Asia are likely responsible for some
cyclones that reach the U.S. West Coast several days
later. Techniques developed in FASTEX for identifying
precursors and targeting observations could help to
improve forecasts for both North America and Europe.
A follow-up field experiment is being considered for
the North Pacific.
FASTEX results may lead to a model for everyday weather
monitoring in the future, according to Nelson. Computer
models of the atmosphere (the main source of forecasting
guidance) require a detailed picture of current weather
in order to extend that picture into the future. Where
data are limited-such as over the oceans-it may be
worthwhile to focus data collection on a small area
where storms are developing, rather than on a bigger
area where relatively little is happening. Two major
goals of FASTEX are to develop better techniques for
targeting these sensitive regions, and to measure
how much the targeting will improve computerized forecasts.
Says Nelson, "Research on these targeting strategies
is at a very early stage, but it has the potential
to bring about revolutionary changes in weather forecasting."
Editor's Note: To obtain FASTEX Images see:
http://www.ucar.edu/ucargen/press/fastex.html
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