SSG No 4 - Shipgaz

for accuracy rather than long-range forecasts
to allow shipping to take precautions.
Organizations such as the UK’s MET
Office, the European Center for Medium-
Range Weather Forecast (ECMWF), the US
National Center for Environmental Prediction
(NCEP), the US Navy’s Fleet Numerical
Oceanographic Center (FNMOC) and
even Japan’s JMA produce global weather
forecasts for up to five days and beyond.
Not all services are free of charge, but some
are available on the Internet or on marine
weather fax to shipping.
Lose accuracy beyond 6–7 days
Generally forecasts tend to lose accuracy
beyond 6–7 days. But with today’s satellite
communication every ship equipped with
GMDSS (Global Maritime Distress & Safety
System) can be reached instantly. Ships
at sea can now download 10 days of wind
and wave forecasts in a few minutes. In
other words, the information is available,
and much of it is free of charge.
In 1988, the IMO amended the Safety
of Life at Sea (SOLAS) Convention,
requiring ships subject to it fit GMDSS
equipment. Such ships were required to
carry NAVTEX and satellite EPIRBs by
August 1, 1993, and had to fit all other
GMDSS equipment by February 1, 1999.
US ships were allowed to fit GMDSS in
lieu of Morse telegraphy equipment by the
Telecommunications Act of 1996, according
to the US Coast Guard.
The GMDSS consists of several systems,
some of which are new, but many of which
have been in operation for many years.
The system will be able to reliably perform
the following functions: alerting (including
position determination of the unit in distress),
search and rescue coordination,
locating (homing), maritime safety information
broadcasts, general communications
like weather forecasts, and bridge-to-
bridge communications. Specific radio carriage
requirements depend upon the ship’s
area of operation, rather than its tonnage.
The system also provides redundant means
of distress alerting, and emergency sources
of power.
Therefore, there is no excuse for not taking
the necessary precautions to avoid
damage to ship and cargo. Believe it or not,
seafarers ignore severe weather warnings all
the time. As severe weather gets ever more
violent, the attitude of many captains can
have serious consequences, sometimes
even with loss of life as a result. In this
issue we talk of the “Zombies” of the
Dover Strait, and elsewhere, we are pretty
sure. They trundle up the lanes with their
AIS turned off and, by the looks of it, are
running on autopilot, apparently oblivious
to the fact that they are in the busiest shipping
lane in the world.
Cats and dogs, sprats and turtles
We all know the expression “raining cats
and dogs”. But what if it rained fresh
sprats? In a freak incident in August 2000 a
shower of dead, but still fresh sprats rained
down of the British fishing port of Great
Yarmouth. It was caused by a small tornado,
which trawled up water and anything
in it and showered it on the small town.
When the tornado reached land it lost its
IT & COMMUNICATIONS
This map is from
the European
Center for
Medium Range
Forecasting
(ECMWF) and
shows a three-day
forecast. Surface
data are mean sea
level pressure and
wind speed
measured in
metres per second.
energy and the sprats fell out of the sky.
The magazine Nature told of a severe
hailstorm in the US, where a gopher turtle,
6 inches by 8 inches and entirely encased
in ice, fell with the hail.
Forecasting
Real-time observations are often used to
generate weather charts, which are generally
available to shipping. The forecasts
embedded in these charts attempt to predict
the future weather patterns and conditions
ranging from two to seven days. As
we noted earlier, any forecast beyond 6–7
days is getting progressively more unreliable.
In order to remedy this, very sophisticated
computers are used for analysis of a
huge quantity of real-time data.
The essence of the forecasting useful to
shipping for routing purposes is up to 6–7
days. Shipping is basically looking for wind
and wave forecasts, and these are difficult
to produce with the sort of accuracy
required for optimal routing of a vessel.
The European Center for Medium-Range
Weather Forecast (ECMWF) produce useful
surface forecast charts. ECMWF, which
is a European Community weather analysis
bureau, is based at Reading in the UK. The
bureau analyses data and provide regular
forecasts for up to one week.
petter arentz
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SCANDINAVIAN SHIPPING GAZETTE • FEBRUARY 23, 2007 41