Sanjeev Kumar Patro

Bhubaneswar: The countdown to landfall of super cyclone Amphan begins. Almost in the next 24-hours, SCS Amphan will make landfall. Even at this moment, there seems a divergence among the Met scientists world over regarding the exact place of landfall.

While IMD DG Mrityunjaya Mohapatra today reiterated that super cyclone Amphan will be making landfall at around evening hours tomorrow (May 20) between Sagar Islands (WB) and Hatiya Islands (Bangladesh), other reputed models like ECMWF, GFS, ICON and JAMA predict the landfall place little west to the IMD's predicted landfall place.

What looks more interesting is there is even disagreement among Indian models regarding the track SCS Amphan will follow before landfall.

NCUM: The National Centre for Medium Range Weather Forecast (NCMRWF) has three models NCUM, NEPS and UMREG.  NCUM and NEPS have predicted landfall between Sagar and Hatiya Islands, which IMD has been using. (see the images below)

[caption id="attachment_452447" align="aligncenter" width="300"]Cyclone Amphan Track Left: NCUM track forecast, Right: NCEP forecast[/caption]

But UMREG model predict the landfall little west to IMD's official forecast. (see the image below)

[caption id="attachment_452449" align="aligncenter" width="300"]Amphan Cyclone Track forecast by NCMRWF's UMREG model[/caption]

ECMWF: Most accurate forecaster European Centre for Medium Range Weather Forecast has today changed its track forecast. It now shows the landfall place between north Odisha- West Bengal coast. ECMWF puts the probability at over 90 per cent. (see the image below)

[caption id="attachment_452451" align="aligncenter" width="300"]Cyclone Amphan Track Forecast Source:ECMWF[/caption]

US-GFS: In a significant coincidence, the US-based National Oceanic and Atmospheric Administration's (NOAA) GFS model indicates the landfall place as extreme north Odisha - West Bengal coast. (see the image below)

Cyclone Amphan

ICON: The prediction by ICON model of German Met service and Max Planck Institute is in unanimity with US-GFS, ECMWF and UMREG (India). The model forecast that the landfall will be in West Bengal, but very close to extreme north Odisha coast.

cyclone Amphan

JAMA: The Japan Met Agency in its latest forecast has predicted that the landfall of cyclone Amphan will take place in the evening hours of tomorrow, and the landfall will be in West Bengal but very close to extreme north Odisha coast.

cyclone Amphan track

 

CMC: The Canada Met Centre is the only Met agency in world, which have maintained consistency over the landfall place. From day 1, it has predicted that landfall place will be Bangladesh (see the image below)

cyclone maphan landfall

Why the variation?

As per NCMRWF study, improper capturing and tracking of the vortex may lead to error in track forecast, especially the landfall place. In an analysis on tropical cyclone forecast in India, Director of NCMRWF, EN Rajagopalan, had mentioned that tracking by using higher resolution and dynamic core show less error.

Landfall Forecast Error Till Date in India

The analysis by EN Rajagopalan shows the landfall error (in Km)in the range of 48 - 345.

cyclone Amphan landfall

 And more errors were noticed in tropical cyclones that took recurve. (See the image)

[caption id="attachment_452457" align="aligncenter" width="300"]cyclone Amphan landfall DPE: Direct Positional Error (in Km)[/caption]

 

 Also Read : Super Cyclone Amphan loses ‘Eye’, will go for a ‘replacement’!

 

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