;Nnews
Science | DOI: 10.1145/2018396.2018402
Kirk L. Kroeker
modeling
chaotic storms

Scientists say improvements to extreme-weather prediction
are possible with new weather models and a reinvention
of the modeling technologies used to process them.

The WArninG time f o r t he onset of extreme weather is far greater today than it was 20 years ago, when only a few minutes of warning could be given for tornadoes, and only half of them could even be predicted. Today, new data-collection technologies, such as Doppler radar and satellites, have improved the ability to identify and track hazardous weather. But scientists say further improvements to warnings’ lead times will not come primarily from the physical systems that gather weather data, but from improving the modeling technologies used to process the data, and from improving the prediction models.

Even with the best data-collection
technology, weather-tracking systems
cannot be effective at predicting what
might come next without refined pre-
diction models that take into account
advanced physics and other factors
that make running such models a task
that takes so long, even on the fast-
est supercomputers, that the results
are not timely enough to be useful.
Steve Koch, who was the director of
the Global Systems Division at the U.S.
National Oceanic and Atmospheric Ad-
ministration’s (NOAA’s) Earth Systems
Research Laboratory (ESRL) before be-
coming director of its National Severe
Storms Lab (NSSL), is focused on devel-
oping advanced computing architec-
tures to improve this situation.

minutes by using more advanced radar
technologies, but ultimately if we want
to get to a one-hour forecast of a tor-
nado, we cannot do that right now just
with radar.”
Koch, who has been working at
NOAA for more than a decade, says the
organization is focusing extensively
on global models, not only of weather
but also of climate and the influence
of oceans, land surfaces, ice and snow,
aerosols, and other factors, including
everything from anthropogenic ef-
fects on climate to invasive species in
the Great Lakes. As a result, this focus
has produced what Koch calls an “ex-
plosion of modeling” in the past few
years. “There is great interest in inte-
grating as many of these processes as
possible into a coherent, scientific ap-
proach to the problem of forecasting
the Earth system,” he says.

in the Warn-on-forecast system being developed at the National severe storms Laboratory, an emerging thunderstorm is observed by radar (left). that radar data is used as input for an ensemble of prediction models to determine the probability of a tornado during the next hour. the blue shading represents tornado probability, while the white dashed lines indicate the storm location in minutes from the present. thirty minutes later (right), a thunderstorm is observed by radar over the area of greatest tornado probability, as predicted.