Super Typhoon Nock-Ten Heads for a Christmas Day Landfall in the Philippines

Typhoon warnings are flying in the Philippines as Super Typhoon Nock-Ten steams westwards at 8 mph towards the Philippine island of Catanduanes. Nock-Ten is expected to make landfall there on Christmas Day as a major Category 3 or 4 storm, then continue westwards, gradually weakening due to land interaction, passing very close to the capital of Manila on Luzon Island the day after Christmas as a Category 1 storm. Nock-Ten likely peaked in intensity on Saturday morning, when the Joint Typhoon Warning Center (JTWC) estimated that the storm had sustained 1-minute winds of 150 mph and the Japan Meteorological Agency estimated a 915 mb central pressure. Satellite loops late Saturday morning showed that Nock-Ten had grown slightly less organized compared to early Saturday morning, with an eye that was less distinct. Some erosion of the storm’s eyewall on the west side was apparent, likely caused by dry air to the west. Microwave satellite imagery on Saturday morning showed that Nock-Ten had developed a tiny 6-mile diameter eye surrounded by a concentric outer eyewall, indicating that an eyewall replacement cycle (ERC) might be underway. During an ERC, the inner eyewall gets unstable and collapses, resulting in a temporary weakening of the storm by 10 - 20 mph for up to 24 hours, until the outer eyewall can stabilize and take over as the the storm’s main eyewall. With Nock-ten experiencing low wind shear of 5 - 10 knots and traversing very warm waters of 29°C (84°F)—1°C (1.8°F) above average—re-intensification after the ERC completes is possible, and satellite imagery early Saturday afternoon did show Nock-Ten had become more organized, with a prominent eye reappearing. However, the storm doesn’t have much time to intensify before interaction with land starts to weaken the typhoon, and dry air to the west may also interfere with intensification. Thus, it is unlikely that Nock-Ten will achieve Category 5 status.


Figure 1. MODIS satellite image of Nock-ten taken at approximately 06 UTC December 24, 2016. At the time, Nock-ten was a Category 4 super typhoon with 150 mph winds, approaching the Philippines. Image credit: NASA.

The strongest Christmas Day typhoon for the Philippines
Nock-Ten will not be the first typhoon to hit the Philippines on Christmas Day, but it will likely be the strongest. The other two typhoons to hit the islands on Christmas Day were Category 2 Typhoon Lee in 1981 and Category 2 Typhoon Jean in 1947. The worst tropical cyclone in world history to strike on Christmas Day was Category 3 Cyclone Tracy, which devastated Darwin, Australia in 1974, killing 71 people and destroying 80% of the homes in the city.

According to NOAA’s historical hurricane archive, only seven major typhoons of Category 3 or stronger intensity have hit the Philippines in December:

Category 4 Typhoon Harriet on December 31, 1959 (145 mph winds)
Category 3 Typhoon Opal on December 14, 1964 (115 mph winds)
Category 4 Typhoon Nanmadol on December 2, 2004 (135 mph winds)
Category 3 Typhoon Hagupit on December 6, 2014 (125 mph winds)
Category 5 Typhoon Gilda on December 18, 1959 (160 mph winds)
Category 4 Typhoon Manny on December 9, 1993 (130 mph winds)
Category 5 Typhoon Bopha on December 3, 2012 (170 mph winds)

If Nock-Ten hits the Philippines with 145 mph winds or stronger, it will be the strongest landfalling storm in the Philippines so late in the year. The strongest non-landfalling typhoon ever recorded so late in the year was Super Typhoon Hester, which peaked as a Category 5 storm with 185 mph winds on December 31, 1952, about 1,000 miles east of the Philippines. Hester recurved out to sea without affecting any land areas.


Figure 2. Radar image of Nock-ten taken at approximately 1 pm EST December 24, 2016. Image credit: The Philippines’ weather service (PAGASA).

Nock-Ten likely to be a highly destructive storm for the Philippines
The projected track and intensity of Nock-Ten over the Philippines are similar to that of Typhoon Rammasun of July 2014, which killed 106 people and did $871 million in damage to the country, making it the third costliest typhoon in Philippines’ history, behind Haiyan of 2013 ($2 billion) and Bopha of 2012 ($1 billion], After making its initial landfall to the east of Manila as a Category 4 storm, land interaction weakened Rammasun to Category 2 strength with 100 mph winds as it moved over Manila. Rammasun caused widespread havoc in the city of 12.8 million, leaving at least 90% of the residents of metropolitan Manila without power due to toppled poles and downed lines. Nock-ten is expected to be a weaker Category 1 storm when it passes over Manila, and its damage should be lower than that of Rammasun's. Still, damage from Nock-Ten could reach $500 million, which would make it the Philippines’ fifth most destructive typhoon in history. Rainfall from Nock-Ten is expected to exceed 8 inches over the core of its path, according to the 6Z Saturday run of the HWRF model.

Storm surge risk
The Philippines’ weather service (PAGASA) is warning of storm surge heights of up to 2.5 meters (8.2’) near where Nock-Ten makes its initial landfall, on the eastward-facing coastal areas of Camarines Sur, Camarines Norte and Catanduanes. Metro Manila, with approximately 12.8 million people, is also at risk of a damaging storm surge. However, surge heights will be lower there, due to the fact Manila faces to the west, away from the direction the storm is approaching from—and the fact that Nock-Ten should weaken to Category 1 strength before reaching Manila.

Recent research suggests that a worst-case storm like Super Typhoon Haiyan with 190 mph winds—if it were to follow the track of several historical typhoons—could bring a catastrophic storm surge of 3.9 to 5.6 m (13 - 18’) along the western seaboard of Metro Manila, even after the storm weakens due to passing over the land areas required to get to Manila. This was the conclusion of a poster presentation at last week’s meeting of the American Geophysical Union by John Kenneth Belena Suarez of the National Institute of Geological Sciences, University of the Philippines, titled Possibility Of Generating Significant Storm Surge On The Western Seaboard Of Metro Manila, Philippines. The researchers studied historical typhoons since 1951 that had passed over Manila, like Rita of 1978, Collen of 1992, Sybil of 1995, Bebinca of 2000 and Xangsane of 2000. They concluded that if these storms had made their initial landfall as Category 5 super typhoons with 190 mph winds, they would have been able to generate storm surges of 3.9 to 5.6 m (13 - 18’) in Manila. Nock-Ten appears unlikely to be a worst-case storm, fortunately.

Note: the charts and advisories are not working on our main site for Nock-Ten; please use our mobile site to get the tracking maps and advisories for the storm.

Have a safe and happy holiday, everyone!

Jeff Masters