Sanjeev Kumar Patro

Bhubaneswar: Odisha is all set to see a stormy May!  Models by Indian National Centre of Ocean Information Services (INCOIS) did suggest of the cyclonic storm system Fani drifting along the Odisha coast and would be nearing to Chandrabhaga coast by the night of May 3.

While the IMD has indicated formation of a well marked Low Pressure Area (LPA) over east Equatorial Indian Ocean and adjoining southeast Bay of Bengal, it has only maintained that the LPA will turn into a depression by today evening.  The depression then to evolve into a cyclonic storm by tomorrow evening. And the cyclonic storm moving northwest ward drift towards the Tamil Nadu and Andhra Pradesh coast by April 30.

However, a study of a model developed by Indian National Centre of Ocean Information Services (INCOIS) reveals a clear cyclone threat for Odisha  in the first week of May. The local Met senior official Ramesh Kumar Nayak here, though, informed that as of now our assessment is cyclone Fani will have no impact on Odisha.

Though INCOIS model too has predicted conversion of LPA into a tropical depression by  April  27 and evolving into a cyclonic storm with the formation of an eye by the night of April 29, it clearly shows the cyclonic storm instead of making landfall in Tamil Nadu or south AP coast, will keep drifting away from the Tamil Nadu and South Andhra coast to reach near the Odisha coast by morning of May 3. The cyclonic system looks to be very intense, if one goes by the INCOIS model.

However, the wind pattern suggested by the model didn't predict landfall in Odisha as of now.  But what looks certain at least now is coastal Odisha would likely to witness heavy rainfall along the coastal areas from May 2 onwards. The sea would also remain rough and wind speed could roaring over 80 km/hr during the date.

Why Odisha may stave off from the cyclone Fani? Historically, Odisha have witnessed cyclones in September and October only. The cyclone data available with IMD shows Odisha saw cyclone hitting in May only once, that too around 4 -decades back. Recent data reveal cyclones generated during May -June in Bay of Bengal (BoB) had drifted along Odisha coast, only to make landfall in Bangladesh.  But cyclonic conditions along Odisha coast are favourable. An analysis reveals the sea surface temperature of  Bay of Bengal (BoB) along the south Odisha coast is now hovering at over 30 – 31 degree Celsius. This reveals the landmass of Odisha coast adjoining to the sea is having a very high atmospheric pressure. And cyclones are systems that move from low to high pressure fronts

The fact needs to be mentioned here is sea surface temperature of BoB gets heated up during pre-monsoon (April-May) and post Monsoon (September - October). And if the vertical wind shear, means variation of wind's speed and direction, sustains a LPA , then cyclones are a reality in these months in the BoB.

The direction of winds along Odisha coast is around  85 –90 degrees from north, which means they are nearly vertical. And vertical winds play an important role in sustaining a cyclonic storm and influence its movement too.