Tropical Cyclone Forecasts in the DIMOSIC Project -- Medium-Range
Forecast Models with Common Initial Conditions
Abstract
The Tropical cyclone (TC) forecast skill of the eight global
medium-range forecast models which are participating in the DIMOSIC
(DIfferent Models, Same Initial Conditions) project is investigated in
this study. Each model was used to generate 10-day forecasts from the
same initial conditions provided by the European Centre for Medium-Range
Weather Forecasts. There are a total of 123 initial dates spanning in
one year from June 2018 to June 2019 with a 3-day interval. The TC track
and intensity forecasts are evaluated against the best track dataset.
TC-related precipitation and tropical cyclogenesis forecasts are also
compared to explore the differences and similarities of TC forecasts
across the models. This comparison of TC forecasts allows model
developers in different centers to benchmark their model against other
models, with the impact of the initial condition quality removed. The
verifications reveal that most models show slow-moving and
right-of-track biases in their TC track forecasts. Also, a common dry
bias in TC-related precipitation indicates a general deficiency in TC
intensity and convection in the models which should be related to
insufficient model resolution. These findings provide important
references for future model developments.