Cyclone Amphan weakens but threat still exists!

Bhubaneswar: In a big development, the low level circulation of cloud clusters over south Andaman sea and adjoining south-east Bay of Bengal (BoB) becomes less marked today.

The weakening signs become more apparent today as the cloud top temperature of the low level closely circulated cloud clusters over the south Andaman sea dropped to around (-) 62 degrees Celsius on May 6 (See the image below). The temperature on May 5 was (-)75 degree C and was (-) 90 degrees C on May 3.

[caption id="attachment_449488" align="aligncenter" width="650"] Source: Meteologix[/caption]

Another key factor that may aid further weakening of the cyclonic circulation is unfavourable MJO (Madden Julian Oscillation). The MJO will remain weak till May 10. It will gain the amplitude of 1 on and around May 12.

Therefore, IMD, which is also the Regional Specialised Meteorology Centre and responsible for tracking cyclones in North Indian Ocean, has made a big observation today. It said the system will weaken further. However, it predicted no cyclone genesis only till May 11.

But the major caution here is the cyclonic circulation at the lower level over the south Andaman sea persists. Since convection is essential for cyclone genesis, the cyclonic circulation takes care of this very requirement for a while.

What Met Models Predict Today?

INCOIS (Indian National Centre for Ocean Information Services): As per this premier Government of India's ocean research agency, when the Tropical Cyclone Heat Potential (TCPH) over Andaman sea is over 100 kilojoules/cm², the TCHP over the north-west Bay of Bengal (near north Tamil Nadu and South Andhra coasts) stands very high. The value is estimated at around 177 kilojoules/cm². (see the image below).

The wind model of INCOIS, therefore, predicts cyclone genesis around this very area on May 12. (see the image below)

US-GFS: Significantly, the model of US, considered second most accurate in the world of meteorology, toes the INCOIS line. The GFS model also agrees that cyclone genesis will happen on around May 12 at around the same location. (See the image below)

[caption id="attachment_449491" align="alignnone" width="650"] Left: Cyclonegenesis starts, Right: Landfall in Myanmar[/caption]

ECMWF: The most accurate model of the world also predicts cyclone genesis. And the predicted time is May 13. The forecast is the system will intensify further on May 14 and move west-northwest ward, means towards the Indian coasts, only to drift away later.  (see the image below)

ICON: The model jointly developed by reputed Max Planck Institute and German Weather Service is in unanimity with all the three models. The prediction is cyclone genesis will happen on around May 13. (see the image below)

GEM: The model of Canada Met Centre also predicts cyclone genesis in the BoB, like the all above models. The only difference is GEM predicts the cyclone genesis date on May 15 (see the image below).

Landfall Date & Place

As on today, only 2 models, the top two models - ECMWF & US-GFS, have predicted the date and place of landfall. Strangely, both are unanimous that landfall will be in north Myanmar and date will be May 16.

The big observation is Odisha is out of the radar of this evolving cyclone Amphan during the whole course of journey, the models reveal.