Sanjeev Kumar Patro

Bhubaneswar:  With every passing hour, cyclone Amphan seems getting fiercer. The central pressure of system. which was earlier estimated at around 975 hecta pascal (hPa), has fallen  steeply to around 919 hpa during the mid-day today. For which, IMD has already categorised this swirling Amphan as super cyclone.

However, the big respite is the moment the system starts moving parallel to Odisha coast, its central pressure will increase again, and as a result cyclone Amphan will fall back to Extremely Severe Category Storm (ESCS).

But the key cyclone takeaway is, as per world's most accurate cyclone tracker, ECMWF, there is a high probability of over 40 per cent that cyclone Amphan will pass within a striking distance of 120 km from the places in the north Odisha coast like  Bhadrak, Balasore and adjoining parts of Mayurbhanj. The ECMWF advises the local authorities to initiate cyclone mitigating measures in such places. (see the main image)

As the cyclonic storm will be of the stature of ESCS during that moment, the impact will be significant on power infra and kutcha or asbestos houses. Moreover, there will be a significant wave surge and sea swelling, which could result in seawater ingress in low lying areas in the above mentioned coastal districts.

How Furious Is Cyclone Amphan?

As per JTWC (Joint Typhoon Warning Centre) data, cyclone Amphan has a vast cloud structure that is spread over a massive area of 1,111 km. The eye itself is occupying an area of over 15 km, as detected in the enhanced infrared (EIR) satellite imagery. And tightly closed cloud bands are seen encircling the eye.

[caption id="attachment_452249" align="aligncenter" width="300"]Cyclone Amphan in BoB Source: IMD EIR[/caption]

The eye seems getting angry as its temperature has grown warmer; whereas the cloud top temperature is still uber cool, the cloud top temperature is measured at (-) 93 degree Celsius. Eye growing warmer, and cloud top (head) remaining uber cooler suggest to the rapid intensification of the cyclone.

Cyclone Amphan's last minute change of track possible?

As per an analysis done by incumbent IMD DG Mrityunjay Mohapatra, two factors play a key role in sudden change of track of any cyclonic system.

They are: steering ridge and convection (transfer of heat, whereby the warm air rises up rapidly and cooler mass sinks in tandem). Cyclone Amphan is currently seen moving along the western periphery of 85 degree east ridge in Bay of Bengal (BoB).

Moreover, his analysis has also pointed out that if the translational speed of tropical cyclone falls to less than 10 km/hr for full 24 hours, then it was observed that the cyclonic system changes its track suddenly.

In the case of Amphan, as of now, this characteristic is yet to manifest. The good evidence is its intensification  to super cyclone  today. Had the translational speed been slower, the system wouldn't have intensified to super cyclone.

However, next 24 hours will be more crucial, when cyclone Amphan will de-intensify to an ESCS.

Cyclone Amphan Impact On Odisha

*As per ECMWF, places in Gajapati district may see 50km/hr gusting wind speed in early morning on May 19 (Tuesday). 50km/hr gusting wind at Puri offshore also predicted.

*In the afternoon hours on May 19, the gusting wind speed is predicted to gradually increase to around 70km/hr in places like Bramhapur, Puri and Jagatsinghpur. In rest of the coastal area, including Bhubaneswar and Cuttack, the gusting wind speed is predicted to be at 50 km/hr.

*Later, the gusting speed of wind will rise to around 60km/hr in places like Bhubaneswar and Cuttack. The gust is predicted at 80km/hr in the entire coastal stretch.

[caption id="attachment_452250" align="aligncenter" width="300"]Amphan Impact on Odisha Sources: Meteologix/ECMWF[/caption]

*Post midnight or early hours of May 20, the gusting speed will rise in the coastal areas to around 80-100km/hr. Even, cities like Bhubaneswar and Cuttack may witness gusting wind speed at 80km/hr.

*In early morning hours on May 20, the gusting wind speed may touch 110-120km/hr in the entire coastal stretch from Puri - Balasore.

*Mayurbhanj district is also predicted to witness gusty wind at a speed of around 80 km/hr.

*By mid-day, the gusty wind speed will reach around 110-130km/hr in the coastal stretch from Jagatsinghpur, Bhadrak to Balasore. The gusting wind speed will gradually increase towards the evening hours as cyclone Amphan will be heading for landfall in West Bengal and then cross over to Bangladesh.

*Landfall is predicted in the evening hours of 8:30 -9:30 PM, exactly the time when cyclone Bulbul had made landfall in West Bengal last November.

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