WEATHER FORECASTING
Knowing what the weather is going to do
is often a case of simply looking out of the
window, but being able to predict weather
conditions several days in advance is
another matter. Being able to predict
the future is more useful than knowing
whether you’ll need a light jacket or waist-
high rubber waders this afternoon.
But predicting the weather is a difficult
science because there’s a lot going on in
our atmosphere. There’s a lot of data to
be processed from orbiting satellites,
airplanes, ships at sea, land-based
weather stations, and more. But weather
forecasting had more humble origins.
It takes us back 170 years, to Vice-
Admiral Robert Fitzroy, a celebrated
sailor in the British Navy who had been on
the second voyage of the HMS Beagle with
Charles Darwin, would become governor
of New Zealand, and a man who thought
the weather ought to be predictable. It
generally wasn’t of course, and at the time
was considered to be completely chaotic.
Indeed, when the idea of forecasting the
weather a mere 24 hours in advance was
floated in the British Parliament in 185 4,
the whole place rocked with laughter.
In the 180 0s, weather forecasting’s
cutting-edge technology was a frog. Having
caught one, you kept the poor creature in
a glass jar with a small ladder and some
water at the bottom. The idea was that, if
the weather was going to be fine, the frog
would climb the ladder, and if it was going
to rain it would languish at the bottom in
the water. Changing this water every week
or so was considered essential. Indeed,
even today, meteorologists in Germany
are sometimes called ‘Wetterfrosch’, or
weather frogs.IMPROVING ACCURACY
Of course, this was a rather hit and miss
method of weather forecasting, but with
the loss of the ship Royal Charter in bad
weather in 185 9, Fitzroy, who had set up
a small office to worry about the weather
five years earlier, was authorized to start
issuing storm warnings, which
he did with the aid of a new
invention, the electronic
telegraph. From his office
in London, he gathered
information from 15
coastal weather
stations and, if he
thought a storm
was likely, would send
a message to the nearest
port, warning shipping.He developed weather charts known
as ‘forecasts’—a previously unknown
word—and by 186 1, was delivering these
forecasts of the weather two days ahead,
published in The Times newspaper.
Unfortunately, Fitzroy’s forecasts
weren’t always accurate. “Yesterday, at
two o’clock, we received by telegraph
Admiral Fitzroy’s signal of a southerly gale.
The gallant meteorologist might have sent
it by post, as the gale had commenced the
day before and concluded fully 12 hours
before the receipt of the warning,” read a
letter in the Cork Examiner.
However, the office he founded back
in 1854 is still going today. It’s known as
the Met Office, has its headquarters near
the city of Exeter in the south-west of
England, on a street named Fitzroy Road,
and is home to some of the most powerful
supercomputers in the worldWEATHER & SUPERCOMPUTING
The Met Office’s computing
ability is, rather like the
weather, in a state of
change at the moment.
The three Cray XC40
supercomputers it
acquired in 2015 ( 14
petaflops of Haswell Xeons
and Nvidia Tesla GPUs, for
a total of 4 60,0 00 cores) are
still the fastest machines
in the world dedicated to
weather prediction. They’re
a bit old, though, and have
dropped off the Top 500 listof the fastest supercomputers worldwide,
having once held 1 1th place. So, an
upgrade is in order.
A multi-million-dollar deal was signed
with Microsoft in April 20 21, and the Met
Office’s new supercomputer will be twice
as powerful as anything else in the UK.
Each of its four quadrants could take
its place among the top 25 machines
worldwide. With over a million processor
cores, six petabytes of memory, and the
ability to store and process nearly four
exabytes of data (10, 000 years of HD
video), it will be powered by 100 percent
renewable energy and should be up and
running by summer 202 2.
Helen Roberts, a senior operational
meteorologist at the Met Office, says:
“It’s a bit of a hybrid. Some of it will be
on our premises and some of it won’t be,
plus we are making much more use of the
cloud than we have done before. We’ll be
working with Microsoft for a decade or
more on this, and when fully functional, it
will be a big step up in our capabilities.”
That sounds brilliant, but how
do you forecast the weather with a
supercomputer? “At the moment, our
model uses the fundamental physical
equations of the atmosphere,” she
explains. “Effectively what this does is split
the atmosphere into three-dimensional
boxes that go up through the depths of
the atmosphere and right the way around
the globe. It has a resolution of around 10
kilometers at the moment. Knowing what
the atmosphere is doing now is a really
key part of numerical weather prediction.Above: A portrait lithograph made by
Herman John Schmidt of Vice-Admiral
Robert Fitzroy, founder of the Met Office.Right:Helen Roberts is a senior
operational meteorologist at the Met
Office, based in Exeter, UK.A frog in a jar was the cutting edge
of 1800 s weather forecasting tech.predicting the unpredictable