Genesis

The frequency is very less over the west Arabian Sea mainly due to colder Sea surface temperature (SST). The genesis of cyclonic disturbances varies with respect to season. While genesis mostly takes place in lower latitudes in association with inter-tropical convergence zone (ITCZ) during pre-monsoon (March-May) and post-monsoon (October-December) seasons, it occurs over northerly latitude during monsoon season (June-September). Though, the frequency is very less, sometimes there is in-situ development of cyclonic disturbances or migrations from northwest Pacific in winter season (January-February) also.

Fig.1 (a) Frequency of genesis of cyclonic disturbances over the NIO during winter season

Fig.1 (b) Frequency of genesis of cyclonic disturbances over the NIO during pre-monsoon season

Fig.1(c) Frequency of genesis of cyclonic disturbances over the NIO during monsoon season

Fig.1(d) Frequency of genesis of cyclonic disturbances over the NIO during post-monsoon season