On October 11, Cyclone Titli made a landfall in Andhra Pradesh coast, entered Gajapati district of coastal Odisha, made a surprise turn towards adjoining districts, and continued as severe cyclonic storm and deep depression for more than 48 hours, leaving 59 people dead in its wake before finally dissipating over West Bengal.
Cyclone Titli’s track is unprecedented in 200 years of cyclone track record, observes Regional Integrated Multi-hazard Early Warning System (RIMES) report on the post-landfall impacts of Cyclone Titli. Cyclonic storms generally lose strength after landfall.
So far only two cyclones in 200 years of recorded history that struck Odisha Coast retained strength after landfall. The 1999 Odisha super cyclone and Titli cyclone.
The 1999 super cyclone remained near the coast for 36 hours and re-entered the ocean before finally dissipating. It managed to retain its intensity due to the presence of moist coastal winds thus inducing prolonged rainfall. Nevertheless, the 1999 super cyclone largely remained a coastal and marine hazard.
On the other hand, Cyclone Titli re-curved inland and travelled to southern and central Odisha districts far from the coastal zone. It retained its destructive potential after landfall for more than two days causing heavy rainfall and landslides in many parts of Odisha.
Thus, Cyclone Titli proved to be an all dimensional hazard: non–coastal, coastal and marine. RIMES report also observes that a cross-country assessment of cyclones reveals that although cyclones associated with secondary hazards are not uncommon, the unexpected track movement of Cyclone Titli for two days baffled every one-a pattern meteorologists, disaster managers, and residents have never seen before.
It also retained its destructive potential as it moved far away from coasts and towards the interior districts.
Why did Titli surprised the Indian Meteorological Department (IMD)
Odisha received some heavy rainfall spells – that too towards the end of the monsoon season – in September.
The spells were brought by the low pressure area in the morning of 5th September over northwest Bay of Bengal and vicinity that eventually became a well- marked low pressure area by the evening of the same day. It evolved into a depression and further intensified into a deep depression on 6th September.
It gradually weakened as it crossed the West Bengal coast and moved north-westwards. Under the influence of the system, widespread and very intense rainfall activity occurred over Odisha.
Such events leave the land surface in a very moist condition that supports and enhances the lifetime of post landfall tropical cyclones.
Since land surface processes are still inadequately parameterized in Numerical Weather Prediction models, these interactions are not properly captured and hence not predicted well. As such, IMD calls Titli the rarest of rare cyclones.
Why OSDMA was surprised
Despite the unprecedented nature of Cyclone Titli, the coastal districts achieved zero casualty. This is a remarkable dividend of the investments made by the Odisha government in strengthening cyclone preparedness and response since the 1999 super cyclone that killed 10,000 people.
Armed with the legacy of successfully managing the 2013 Phailin super cyclone with near zero casualty and guided by IMD forecasts, OSDMA evacuated around 300,000 people to safe places well before Titli’s landfall.
IMD’s forecast until Titli’s landfall on 10 October did not indicate a re-curvature track far into the interior zones. Secondary hazards, such as landslides were also not indicated.
Reports indicating landslide-related deaths from remote and mountainous areas were therefore not expected. RIMES global review of early warning information systems revealed that no other country’s experience is of any guide to OSDMA.
Why residents were surprised
Excess end-season September rains enhanced the risk of landslides and flash floods due to the near saturation of soil. This provided an ideal condition for cyclone Titli to trigger floods and landslides in many locations.
Previously, public awareness and early warning information communication experience was confined to coastal zones and remote inhabitants of non-coastal zones were unfamiliar with cyclone risks.
Hence, we see a lot of casualties and damage in the interior districts because there is no experience managing a cyclone associated secondary hazards of such kind, observed RIMES report.
Learning from Titli and moving forward
But every surprise comes with a critical opportunity to improve the current system. Translating impacts into actionable and location-specific early warning information for disaster managers and residents remains a challenge for rare cyclones that cause secondary impacts away from coastal region, such as localized landslides.
On top of the agenda, RIMES states in its report, should be to address this gap to develop a system for translating cyclone movement and strength into sector and location-specific impacts. This needs a robust system for risk assessment and impact-based early warning.
Communicating the expected impacts to district that are at risk, as are efforts to scale up investments in evacuation centers and enhancing emergency response capacities to respond to early warning information.
OSDMA evacuated 300,000 people away the coast before Cyclone Titli’s landfall. OSDMA should be able to replicate this feat in future events,” observes RIMES report.
The Regional Integrated Multi-Hazard Early Warning System for Africa and Asia (RIMES) is an international and intergovernmental institution, owned and managed by its 45 Member States/collaborating countries for the generation and application of early warning information.
RIMES evolved from the efforts of countries in Africa and Asia, in the aftermath of the 2004 Indian Ocean tsunami, to establish a regional early warning system within a multi-hazard framework for the generation and communication of early warning information, and capacity building for preparedness and response to trans-boundary hazards.
*A. R. Subbiah is the Director at RIMES Bangkok, Thailand.