TROPICAL
CYCLONE trajectory forecast products
The ECMWF Tropical
cyclone forecast products are designed to provide both
deterministic and probabilistic information on movement and
intensity of individual tropical cyclones. The system is vitally
dependent on observations from various tropical cyclone centres
around the world. In other words, the TC forecasts does not take
genesis into account - TCs can however die in the process if they
are not forecasted to stay strong enough.
Once observations are
available, the movement of a TC is automatically tracked, both in
the deterministic and the EPS forecasts. The tracking algorithm is
based on extrapolation of past movement and the mid-tropospheric
steering flow to obtain a first guess position. The actual position
is determined by searching for MSLP and 850 hPa vorticity extremes
around the first guess position. Also thickness maximum, wind speed
and orography are evaluated. More details can be found in the
following Tech. Memo
http://www.ecmwf.int/publications/newsletters/pdf/102.pdf. Tropical
cyclone products are presented in the FM 94-IX Ext. BUFR binary
representation.
Tropical Cyclone
products are disseminated separately from other deterministic
forecast products and have their own dissemination schedule (Table
4.12 below).
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