Saturday, May 16, 2015

South West Monsoon 2015 - Update #2 - 21st May for Andaman and early for Kerala.

Nino is here and expected to be a Super El Nino
El Niño–Southern Oscillation (ENSO) indicators have shown a steady trend towards El Niño levels since the start of the year. Sea surface temperatures in the tropical Pacific Ocean have exceeded El Niño thresholds for the past month, supported by warmer-than-average waters below the surface. Trade winds have remained consistently weaker than average since the start of the year, cloudiness at the Date Line has increased and the Southern Oscillation Index (SOI) has remained negative for several months. These indicators suggest the tropical Pacific Ocean and atmosphere have started to couple and reinforce each other, indicating El Niño is likely to persist in the coming months.

Taken from Australian Bureau of Meteorology
Meanwhile, the Indian Ocean Dipole is expected to be just around neutral during next 3 months.
Remember, a positive IOD is good whenever there's an El Nino is in place.

Click here to read more about upcoming "Super" El Nino

Central, N-W India Heat LOW

As of today, 15-May, the Heat LOW over N-W, central,E-central India is doing good. The pressure is around 1000mb over E-central India. This trend is good for attaining 994mb over N-W India around end of May.

Mascarene HIGH pressure system and Cross Equatorial Winds

The high pressure system over South Indian Ocean is slowly moving into position, while the pressure 1038mb is above normal at this point of time. This'll drive more winds towards Somali coast.

In next 3 days (18-May), more cross equatorial winds will reach Somali coast and the Somali low-level jet will slowly start to pick up strength.

By 21-May, the SW Monsoon is expected to reach S,central Andaman Islands and over S,S-E Bay.

Sea Surface Temperature(SST) over Bay and Arabian sea

The Bay and Arabian sea Sea Surface Temperature is around 30 to 32 C. A slight reduction in SST seen along Somali coast, and this should be around 20 C during the last week of May.


Can West or W-central Bay pop a strong circulation or LOW?
According to latest GFS, Only a weak circulation expected over N-central Bay on 19-May and move N-E.
A central Bay LOW around 20-May will be good for the SW monsoon winds to reach S,S-E Bay and S,central Andamans.

As of now the Monsoon onset over Kerala is on right track, It may enter around 26/27-May itself !!
A small component of monsoon current can affect S-tip Tamilnadu and S Kerala coast from 23-May !!
Srilanka is expected to get Monsoon rains from 23-May !

Upper-Level 200mb Jet

Today, the upper-level jet is from East upto 10 north. This is good for the Monsoon onset over Srilanka, S,S-E Bay, S Andaman and even for S-tipTamilnadu and S Kerala.

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