Mesoscale Modelling for Tropical Cyclone Forecasting over the North Indian Ocean - Monitoring and Prediction of Tropical Cyclones in the Indian Ocean and Climate Change - page 280

4. Conclusions
From the above results and discussions, the following broad conclusions are
drawn:
(i) ARW model could provide better forecast guidance up to 72 hours with
reasonable errors. The mean track errors varies from 130 km to 400 km
from 12 to 72-hour forecast and the landfall position errors range from
70 km to 140 km in advance of 24 to 72-hour lead for the NIO TCs. The
initial vortex position error in the GFS analyses is about 80 km which
consequently leads to such track errors.
(ii) The assimilation of satellite-derived sea surface winds can significantly
improve the initial position by 34% and hence the mean track forecast by
25%, 22%, 46% and 47% for 24 hr, 48 hr, 72 hr and 96 hr respectively.
The eye structure is improved as well.
(iii) The assimilation of DWR data contributes for improved cyclone
movement as it could provide a more realistic large-scale environmental
field even when the cyclone is away from the radar location which implies
for better initial vortex, low-level (850 hPa) relative vorticity, upper-
level divergence field and steering current.
(iv) The assimilation of both conventional and non-conventional data sets
improves the track prediction of tropical cyclones over NIO using NMM
model. The mean improvement of 21%, 25% and 34% is evaluated at
initial, 24-hr and 48-hr forecast of model integration.
Acknowledgements
The Indian National Centre for Ocean Information Services (INCOIS) is
gratefully acknowledged for providing financial support to carry out this
research. The authors also owe thanks to IMD for providing best track
parameters of TCs used for the validation of model simulated results.
REFERENCES
Davis, C.A., Wang, W., Chen, S., Chen, Y., Corbosiero, K., DeMaria, M., Dudhia, J.,
Holland, G., Klemp, J., Michalakes, J., Reeves, H., Rotunno, R. and Xiao, Q. (2008).
Prediction of landfalling hurricanes with the advanced hurricane WRF model. Mon.
Wea. Rev. , 136: 1990-2005.
Gao,, J., Xue, M., Shapiro, A., Droegemeier, K.K. (1999). A variational method for the
analysis of three-dimensional wind fields from two Doppler radars. Mon. Weather
Rev ., 127: 2128-2142.
Janjic, Z.I. (2001). Nonsingular Implementation of the Mellor-Yamada level 2.5 scheme
in the NCEP meso model. NCEP Office Note No. 437.