Sanjeev Kumar Patro

Even as the countdown to season’s first low pressure in Bay of Bengal has begun, satellite images show low and medium clouds with weak to moderate convection intensity in the north Bay.

But clouds having intense to very intense convection have been spotted in the south BoB.

As per model data, these high convective clouds when reaches the east central BoB, the favourable conditions there will then shape up as cyclonic circulation on May 22, which will further steam up to become a low pressure area on May 23.

How the conditions are favourable?

The sea surface temperature is hot enough to provide the latent heat to developing storm.Data with IMD puts the current SST at 30-31 deg C.

  • It says there is a positive upper level divergence. This is very significant as such a condition will give a boost to cyclone genesis by helping the air mass to rise up.
  • The vertical wind shear is moderate.
  • A positive vorticity withvertical extension up to 200HPA observed.

In the backdrop of such congenial factors, the met agencies worldwide, including IMD, forecast brewing up of a cyclonic storm in Bay.

Why IMD Says Cyclone Yaas Will Come Knocking Odisha – West Bengal Way?

The country’s ace cyclone prediction agency said so going by the location of the low pressure area that is to take shape on the evening of May 22.

Since cyclones always chart a northwest track, Odisha and West Bengal come on its way, the data suggests.

Moreover, the model data of IMD, IITM CGEPS (MME), US-GSF,; ECMWF suggest that the system will initially move in north direction, only tolater chart the north west route – the route where Odisha landmass figures prominently.

As per Regional Specialised Metrological Centre. (RSMC), New Delhi, the apex cyclone warning centre in South Asia, there is a convergence among top numerical Models like IMD-GFS, US-GFS, ECMWF etc that this developing cyclonic system will chart it’s track in the north west direction.

Cyclone Yaas Intensity

The weather models of ECMWF, US-GFS etc, which IMD follows have put the central low pressure of the system at around 960 mb – which means the intensity of the cyclone will be a notch higher than Bulbul ( central pressure 976mb).

It seems clear at present that the intensity of Cyclone Yaas will not be that of Fani (932 mb) and Amphan (920mb).

Cyclone Yaas Landfall Forecast

Weather men say the landfall place of cyclone Yaas depends on its direction of movement.

Though IMD till date has only hinted that the system will move towards Odisha and West Bengal coast, the models (ECMWF, GFS), which found mentioned in the latest RSMC bulletin, have predicted that going by the north west movement of the system, it is very likely that Cyclone Yaas will make landfall between Kendrapada and Balasore on the night of May 26.