The “Deep Depression” (categorized by the Indian Meteorological Departments (IMD) based on peak wind speed) is currently 120km East of Mullaitivu in the Bay of Bengal and shall reach Cyclonic Storm speeds by noon. By 10.00am SL time, the Indian Meteorological Departments specialized cyclone unit is predicting it to steer North-Eastwards along the Kilinochchi and Jaffna coasts (150 km, 170 km respectively) with a peak wind speed of 55km/h – 65 km/h over the next two days. IMD predicts that around noon on the 28 th , the Deep Depression shall upgrade in peak speed into a Cyclonic Storm –then it shall be named as Cyclone Fengal – an Arabic name. The map describes the path of the storm track predicted by the IMD in the next two days along with its distance to Sri Lanka’s coastal towns.

   

Note that even if the storm is remote, there could be still serious impacts on Sri Lanka due to the impact of high
winds and unusual mountain induced rainfall due to these winds.

Nomenclature of Storms

Wind circulation systems with a low-pressure core region and high wind speeds that are rotating have nomenclature among meteorologists in India as a Low-Pressure Area (LPA), Depression, Deep Depression, Cyclonic System and Super-cyclone.

A “Depression” (D) wind speed between 17-27 knots (20-30km/h).
A “Deep Depression” (DD) has wind speeds between 28-33 knots (50-60km/h).
A “Cyclonic Storm” (CS) is. (60-85km/h)

Predictions of Northern Indian Ocean Storms

Cyclonic predictions are based on computer models that is a specialized area in meteorology – lately the cyclone track predictions have become more precise spatially and the IMD is one of the advanced in this area. The IMD has the advantage that it has focused satellites over the region and thus has more precise initial conditions. The JTWC – the Joint Typhoon Warning Center of the US Navy also issues cyclone tracks given its interests in Chagos where it has a base obtained from Great Britain and also its vessels. It too issues track once, there is a cyclone.

About FECT

The Federation for Environment, Climate and Technology is a research institute based in Kandy which originated out of a two decade collaboration with the International Research Institute for Climate and Society and the Columbia University Water Center in New York and has been hosted by the Mahaweli Authority of Sri Lanka in Kandy. It has been issuing a weekly climate bulletin for Sri Lanka for 15 years based on