Powerful Cyclone Phailin not a Mega-Disaster for India

Tropical Cyclone Phailin has weakened to a tropical storm over northern India after making landfall on the northeast coast of India near the town of Gopalpur (population 7,000) at 15:45 UTC (11:45 am EDT) on Saturday, October 12, 2013. According to media reports from the BBC, the cyclone brought a storm surge in excess of 3 meters (10 feet) to portions of the coast, and at least fourteen people had been killed by the storm. Phailin was weakening substantially at landfall, due to interaction with land, and was rated a Category 4 storm with 140 mph winds by the Joint Typhoon Warning Center (JTWC), four hours before landfall. The pressure bottomed out at 938 mb in Gopalpur as the eye passed over, and the city reported sustained winds of 56 mph, gusting to 85 mph, in the eyewall. A 938 mb pressure is what one expects to find in a Category 4 storm with 140 mph winds, using the "Dvorak technique" of satellite wind and pressure estimation, but I expect Phailin's winds were at Category 3 strength, 125 - 130 mph, at landfall, due to the eyewall replacement cycle that was going on at the time. The India Meteorology Department (IMD) still rated Phailin as a Category 2 storm with winds over 100 mph six hours after making landfall, when it was about 60 miles inland. Satellite images show that Phailin's most intense thunderstorms and heaviest rains are no longer near the coast, but have pushed inland near the India/Nepal border. Rainfall amounts as high as 9.49" (241 mm) were reported in the Odisha region where Phailin made landfall.


Figure 1. MODIS satellite image of Tropical Cyclone Phailin, taken at approximately 07:30 UTC on October 13, 2013. At the time, Phailin was a tropical storm with winds 70 mph. Image credit: NASA.

A victory for India's cyclone evacuation and preparation efforts
While we have yet to hear from the worst affected area, the town of Gopalpur in Odisha where the eye of Phailin came ashore, it is clear that India has avoided a humanitarian mega-disaster like occurred in October 1999, when the great 1999 Odisha Cyclone killed nearly 10,000 people in the same region of the county. The India Meteorology Department (IMD) provided excellent early warning information for Phailin, predicting on October 9 that the cyclone would strike on October 12 with at least Category 2-strength winds. Civil defense in India took the warnings seriously, and operated the largest evacuation effort in the nation's history--nearly 1 million people--one that undoubtedly saved hundreds of lives. There were far more shelters available to put the evacuees in, compared to in 1999, thanks to a major effort to build more shelters after the cyclone. The high death toll in the 1999 cyclone was blamed, in part, due to lack of shelters.

How strong was Phailin?
According to satellite strength estimates made by the U.S. Joint Typhoon Warning Center (JTWC), Phailin was just as strong as the great 1999 Odisha Cyclone, 12 hours before landfall. Both storms were rated as Category 5 storms with winds of 160 mph. The India Meteorological Department (IMD) strength estimates for Phailin were considerably lower than that of JTWC, but since both centers use satellite estimates rather than direct measurements of the winds and pressure, we don't know which center was correct. It is true that satellite estimates using the same techniques give different central pressures for the Atlantic and Pacific Oceans--i.e., a storm with the same appearance on satellite imagery will have a higher pressure in the Atlantic than in the Pacific (see this chart of the differences.) However, the satellite estimates give the same winds for each ocean, since the lower pressures in the Pacific are due to the fact that background pressures in the Pacific are lower, and it takes a much lower central pressure to generate the same winds as in an Atlantic storm. It may be the satellite-wind relationship is different in the Indian Ocean, though. IMD has looked at some buoy data to try and calibrate their satellite strength estimates, but high-end tropical cyclones are uncommon enough in the Indian Ocean that I doubt we really know whether or not Indian Ocean cyclones have the same winds as a hurricane in the Atlantic with the same satellite signature. Another thing to consider is that the IMD uses 3-minute average winds for their advisories, and JTWC uses 1-minute, so the winds in the IMD advisories will be lower by at least 2%, due to the longer averaging period. (I said incorrectly that IMD uses 10-minute averaging times in my Saturday blog post.) We need a hurricane hunter aircraft in the Indian Ocean to fly into tropical cyclones and take measurements of the actual winds to resolve the issue.


Figure 2. Triple trouble: Tropical Cyclone Phailin, Typhoon Nari, and Typhoon Wipha parade across the Earth in this MODIS satellite image montage taken on October 13, 2013. Image credit: NASA.

Typhoon Nari heads for Vietnam
Category 2 Typhoon Nari is headed for landfall in Vietnam, after battering the Philippines on Friday. Nari killed thirteen people and left 2.1 million people without power on the main Philippine island of Luzon, after hitting on Friday night near midnight local time as a Category 3 typhoon with 115 mph winds. The core of the storm passed about 80 miles north of the capital of Manila, sparing the capital major flooding, but the storm dumped torrential rains in excess of ten inches to the northeast of Manilla. Nari is under moderate wind shear of 10 - 20 knots, which should keep intensification relatively slow, and increasing interaction with land will also act to slow intensification. Nari is expected to be at Category 1 strength when it makes landfall in Vietnam near 20 - 23 UTC on Monday.

Typhoon Wipha a threat to Japan
Huge and powerful Category 4 Typhoon Wipha continues intensifying as it heads northwest towards Japan. The storm is expected to peak at 145 mph winds on Monday near 12 UTC. By Tuesday, Wipha will recurve to the northeast and begin weakening, passing just offshore from Tokyo, Japan, sometime between 00 - 06 UTC on Wednesday. Wipha will be rapidly weakening as it makes its closest approach to Tokyo, due to high wind shear and cooler waters, and the coast of Japan should experience winds below hurricane force if the core of Wipha passes offshore as expected. High winds and heavy rains from Wipha may be a concern for the Fukushima nuclear site, where rainfall from Typhoon Man-Yi on September 16 complicated clean-up efforts of the reactors damaged by the March 2011 earthquake and tsunami.

98L in the Eastern Atlantic disorganized
A tropical wave (Invest 98L) 900 miles east of the Lesser Antilles Islands is headed west-northwest at 10 mph. Satellite loops show that 98L has lost most of its organization and heavy thunderstorms. The disturbance is under a high 20 - 30 knots of wind shear, and the shear is expected to remain high for the next two days. In their 8 am EDT Saturday Tropical Weather Outlook, NHC gave the disturbance 2-day development odds of 10%, and 5-day odds of 10%. 98L's projected west-northwest track is expected take it close to the Northern Lesser Antilles Islands by Thursday, according to the 00Z Sunday run of the European model.

Moisture associated with Tropical Storm Octave in the Eastern Pacific bringing rain to Texas
In the Eastern Pacific, Tropical Storm Octave is headed NNW towards Mexico's Baja Peninsula, but is expected to dissipate before making it there. Octave is embedded in a large plume of tropical moisture that is riding up to the northeast over Mexico and Texas. Flood Watches are posted over large regions of Texas, where widespread rains of 2 - 4", with some 6 - 8" amounts, are expected.

Jeff Masters