Tropical cyclone 'Hikaa' seems to be enjoying a supportive environment for sustenance even as the storm heads for a landfall to the South of Masirah, Oman, over the next few days.

The cyclone is buffeted by 'moderate' vertical wind shear (change in wind speed and direction with height) of 24- to 37 km/hr, higher values of which can cap the storm strength.

Landfall area

The warm sea-surface temperatures of 29 to 30 degree celsius (the threshold limit is 27.5 degree celsius) will aid the convection (the process of cloud-building), favouring the system strength in the short term.

However, the prospect of penetration of dry air from the hot Arabian peninsula may act against it acquiring further strength, according to the US Joint Typhoon Warning Centre (JTWC).

Almost all global models are in overall agreement with the initial West-South-West track for cyclone 'Hikaa' taking it towards the Masirah Island, 513 km to the South of Muscat, it added.   

In a noon update, India Met Department (IMD) said the cyclone has travelled nearly to the west and located it about 490 km West-South-West of Veraval (Gujarat); 520 km South-South-West of Karachi (Pakistan); and 710 km East-South-East of Masirah. 

It also chose to differ slightly from the JTWC guidance and put 'Hikaa' on a track to the west towards the Oman coast, strengthening a round in the process, before hitting coast during early hours of Wednesday as a deep depression.

Buzz in bay

The Directorate-General of Meteorology, Oman, too agreed saying that numerical weather predictions indicate gradual weakening of the cyclone while approaching the coastal areas of the Sultanate.

It also expected that the Governorates of Southern Al Sharqiya and Al Wusta to be affected by the direct impact of the system beginning from tomorrow (Tuesday) with isolated heavy rain.

The state of the sea is expected to be 'rough' sea over the coastal areas of South Al-Sharqiya and Al-Wusta with maximum wave height between 10 to 13 ft while it will be 'moderate' over the rest of the coastal areas with maximum wave height between five and eight feet.

Meanwhile, back home, the IMD said a persisting cyclonic circulation over West-Central Bay of Bengal off the North Andhra Pradesh coast has shifted base to lie close to the South Andhra Pradesh and North Tamil Nadu coasts.

This is where it expects another low-pressure area to build, which is capable of sending an associated rain wave into the South Peninsula during the latter part of the week.