India Braces for Extremely Dangerous Tropical Cyclone Phailin

Dr. Jeff Masters' WunderBlog

India Braces for Extremely Dangerous Tropical Cyclone Phailin

Posted by: Dr. Jeff Masters, 2:01 PM GMT on October 11, 2013

+43

Extremely dangerous Category 5 Tropical Cyclone Phailin is closing in on the northeast coast of India on the Bay of Bengal. Phailin put on a phenomenal burst of rapid intensification on Thursday, going from a tropical storm with 65 mph winds to a top-end Category 4 storm with 155 mph winds in just 24 hours. After reaching peak intensity near 8 pm EDT Thursday, Phailin--whose name means "a sapphire" in Thai--began an eyewall replacement cycle. The eyewall collapsed, and a new, larger-diameter eyewall formed from an outer spiral band. This process typically weakens the top winds of a tropical cyclone by 5 - 15 mph, and satellite estimates of Phailin's central pressure increased from 910 mb to 934 mb during the eyewall replacement cycle, from 04 - 11 UTC Friday. However, satellite images show that Phailin has completed its eyewall replacement cycle and is now re-intensifying, with the cloud tops of the very intense thunderstorms in the eyewall expanding and cooling, as updrafts in the eyewall grow stronger and push the clouds higher into the atmosphere. The latest satellite estimate of Phailin's central pressure had dropped to 920 mb as of 13 UTC (9 am EDT) on Friday, and the Joint Typhoon Warning Center upped Phailin's intensity to a Category 5 storm with 160 mph winds in their 11 am EDT Friday advisory. Radar out of Visakhapanam, India shows that heavy rains from the outer bands of Phailin are already affecting the coast, and these bands were bringing rainfall rates of over an inch per hour, as estimated by microwave data from 10:55 UTC Friday. Phailin is over ocean waters that have warmed since Thursday, and are now 29 - 30°C. These warm waters extend to a lesser depth than before, and ocean heat content has dropped to a moderate 20 - 40 kJ/cm^2. Wind shear remains low, 5 - 10 knots.


Figure 1. MODIS satellite image of Tropical Cyclone Phailin, taken at approximately 04:30 UTC on October 11, 2013. At the time, Phailin was a top-end Category 4 storm with winds of 155 mph. Image credit: NASA.

Forecast for Phailin
Phailin is likely to be the strongest tropical cyclone to affect India in fourteen years, since the great 1999 Odisha Cyclone. That terrible storm hit Northeast India in the Indian state of Odisha (formerly called Orissa) near the city of Bhubaneswar, as a Category 4 storm with 155 mph winds on October 29, 1999. The mighty cyclone, which peaked at Category 5 strength with 160 mph winds and a 912 mb central pressure shortly before landfall, drove a storm surge of at least 19' (5.9 meters) onto the coast (Kalsi et al., 2004.) The storm stalled just inland, dumping torrential rains on portions of India already saturated from the landfall of Category 4 Tropical Cyclone 04B just twelve days before. The catastrophe killed 9,658 people and left $2.5 billion in damage (1999 dollars), India's most expensive and fourth deadliest tropical cyclone in the past 100 years. The models are in tight agreement that Phailin will make landfall in Northeast India on Saturday between 09 - 15 UTC about 100 miles to the southwest of where the 1999 cyclone hit. The India Meteorological Department (IMD) is predicting that a storm surge of up to 3 meters (ten feet) will hit along a swath a coast to the right of where the center makes landfall. This region of the coast is not as low-lying, which should keep the death toll due to storm surge much lower compared to the 1999 Odisha Cyclone, where more than 70% of the deaths occurred due to the storm surge. Deforestation of the coastal mangroves in the storm surge zone was associated with increased death toll in that storm, according to Das and Vincent (2009), who concluded, "villages with wider mangroves between them and the coast experienced significantly fewer deaths than ones with narrower or no mangroves.". Given Phailin's recent recovery from its eyewall replacement cycle and subsequent re-intensification, I expect that Phailin will hit the coast as a Category 4 storm with a strength very similar to that of the 1999 Odisha Cyclone.


Figure 2. Elevation of the Odisha region of India, with the track of the 1999 Odisha cyclone and forecast track of Phailin overlaid. Phailin is predicted to hit a region of the coast about 100 miles to the southwest of where the 1999 cyclone hit. The coast is not as low-lying to the southwest, which should result in a lower storm surge death toll. The greatest storm surge occurs along the coast to the right of where the center crosses. Image credit: http://www.globalwarmingart.com

Phailin's heavy rains will be capable of causing very destructive flooding; the 00Z Friday rainfall forecast from the HWRF model (Figure 3) calls for a significant swath of 8 - 16" of rain along the path of Phailin inland. Rains from the 1999 Odisha cyclone killed more than 2,000 people in the town of Padmapur, located more than 150 miles from the coast. Deforestation was cited as a contributing cause to these destructive floods that killed 36% of the town's population.


Figure 3. The 00Z Friday rainfall forecast from the HWRF model calls for a significant swath of 8 - 16" of rain along the path of Phailin inland. Image credit: NOAA/NCEP/EMC Hurricane Forecast Project supported by Hurricane Forecast Improvement Project (HFIP).

India's tropical cyclone history
There is good reason to be concerned when a major tropical cyclone forms in the Bay of Bengal. Twenty-six of the thirty-five deadliest tropical cyclones in world history have been Bay of Bengal storms. During the past two centuries, 42% of Earth's tropical cyclone-associated deaths have occurred in Bangladesh, and 27% have occurred in India (Nicholls et al., 1995.) Wunderground's weather historian Christopher C. Burt has a detailed post on India's tropical cyclone history.

References
Kalsi, S.R., N. Jayanthi N, and S.K. Roy Bhowmik, 2004, "A Review of Different Storm Surge Models and Estimated Storm Surge Height in Respect of Orissa Supercyclonic Storm of 29 October, 1999," New Delhi: Indian Meteorological Department.

Nicholls, R.J.N., N. Mimura, J.C. Topping, 1995, "Climate change in south and south-east Asia: some implications for coastal areas," J Glob Environ Eng 1995;1:137–54.

Das, S., and J.R. Vincent, 2009, "Mangroves protected villages and reduced death toll during Indian super cyclone", Proc Natl Acad Sci U S A. 2009 May 5; 106(18): 7357–7360. Published online 2009 April 20. doi:  10.1073/pnas.0810440106

Little change to 98L in the Eastern Atlantic
A tropical wave (Invest 98L) located about 600 miles west-southwest of the Cape Verde Islands is headed west to west-northwest at about 10 mph. Satellite loops show that 98L has a modest area of heavy thunderstorms with a substantial amount of spin. The disturbance is under a high 20 - 30 knots of wind shear, and the shear is expected to remain high for the next five days. The UKMET model shows some weak development of 98L by early next week, but the European and GFS models do not. In their 8 am EDT Thursday Tropical Weather Outlook, NHC gave the disturbance 2-day development odds of 40%, and 5-day odds of 40%. 98L's projected west-northwest track is expected take it several hundred miles northeast of the Northern Lesser Antilles Islands by the middle of next week, according to the 00Z Friday morning runs of the GFS and European models.


Figure 4. MODIS satellite image of Typhoon Nari, taken at approximately 02:30 UTC on October 11, 2013. At the time, Nari was a Category 3 storm with winds of 115 mph. Image credit: NASA.

Typhoon Nari headed towards the Philippines
In the Western Pacific, we have another very dangerous tropical cyclone--Category 3 Typhoon Nari, which is bearing down on the main Philippine island of Luzon. Nari will make landfall near 16 UTC (noon EDT), bringing the usual hazards of destructive winds, dangerous storm surge, and torrential rains capable of causing life-threatening flash floods and mudslides. The core of the storm will pass about 80 miles north of the capital of Manila, Passage over Luzon is expected to weaken Nari to a Category 1 storm by the time it emerges into the South China Sea between the Philippines and Vietnam. Nari will then have a little over two days to re-intensify before making a second landfall in Vietnam around 18 UTC on Monday.