SEPTEMBER/OCTOBER 2019
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DISCOVER 49
Weather Models 101
Computer models are essential
to create weather forecasts.
Meteorologists use these tools to
predict what the atmosphere is about
to do. Next time you see that rainy icon
on your weather app, remember it took
supercomputers and quadrillions of
calculations to make sure it’s what
you’ll actually see in the sky.
Calculations
To make the model,
the atmosphere
is divided up
horizontally and
vertically, into
a 3D grid that
spans the planet.
Each calculation moves the model forward
a given amount of time.
Now 30 min. 60 min.
Each grid cell is
populated with data
about the current
conditions, such
as temperature,
pressure, humidity
and wind.
The real-time weather
in a single cell
constantly changes.
When the model runs,
it uses the starting
conditions to calculate
how the weather is
expected to change
in each cell.
The model generates
predictions about how
and when it thinks
these changes are likely
to occur, leading to a
weather forecast.
Source: Royal Netherlands
Meteorological Institute (KNMI)
These snapshots can be smoothed out into a weather
forecast map like meteorologists might show on TV.
Now 30 min. 60 min.
How do models work?
A weather model is a bunch of
equations that track and simulate
changes in Earth’s atmosphere
over time. They rely on data from
satellites, radar, balloons and more.