Low Pressure in Bay to revive rainy days over South India

IMD announced the formation of the Pre Monsoon Season’s first Low Pressure Area in Bay over the Equatorial waters off the coast of Sri Lanka.  This development is expected to revive the rainy days over South India for the next week or so after a long dry spell in the region.

March is typically not the time associated with strong disturbances with only seven tropical disturbances of Depression strength & above forming over North Indian Ocean according to IMD Cyclone atlas.

Interestingly Arabian Sea has not organized any strong disturbances during the month of March since 1891 from when the IMD Cyclone Atlas has records for disturbances over the North Indian Ocean Basin.  While in weather there will be exceptions time to time climatology indicates the less probability of this Low Pressure area to develop into a stronger disturbance (Depression / Cyclone).

The Equatorial Waters of Indian Ocean along with the adjoining parts of Arabian is abnormally warm which is likely to provide conducive conditions for the sustenance of this Low Pressure over the next few days.  The warm waters are likely to provide good moisture until the system reaches 12 / 13°N latitude post which the influx of dry continental air from North could degrade the disturbance.

The models are coming in place for the disturbance to move West of Kerala in 2 / 3 days time which is likely to improve the rainfall chances.  If this happens there is a fair chance for a few places along the Western Ghats to get a spell or two of heavy rains due to moisture incursion from the East.  Nevertheless South Tamil Nadu & parts of Kerala will start to receive rains from tomorrow with Tuesday / Wednesday looking good for rains over more places.