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Chan-hom Makes Final Landfall in North Korea

By: Bob Henson and Jeff Masters 3:33 PM GMT on July 13, 2015

After nicking the coast of China as a Category 2 typhoon on Saturday afternoon local time, Tropical Depression Chan-hom made landfall on Monday morning just south of Pyongyang, North Korea, according to the final advisory from the Joint Typhoon Warning Center (JTWC). The mountains of North Korea brought a rapid end to Chan-hom’s life as a tropical cyclone. Damage in China’s coastal province of Zhejiang has been estimated at more than $400 million US, with total losses nationwide estimated at close to $1 billion. One fatality and several injuries were reported in the city of Ningbo, near Chan-hom’s path, where the ceiling of a hotel room reportedly collapsed. Ningbo reported 217 mm (8.54”) of rain from the typhoon. Chan-hom also caused dozens of injuries in Japan, as it passed between the southern islands of Okinawa and Miyako-jima while at Category 4 intensity. On the plus side, the huge urban area of Shanghai and its 23 million residents dodged a bullet with Chan-hom, as a track just slightly further west could have brought a record storm surge into the city. More than 1 million people in China evacuated during the approach of Chan-hom, which was the strongest typhoon to pass within 100 miles of Shanghai in at least the past 35 years.

Figure 1. MODIS image of Typhoon Nangka, taken at 0140 GMT on Monday, June 13, from NASA’s Terra satellite. Image credit: NASA/GSFC.

Nangka intensifies in northwest Pacific
Japan may face a serious threat late this week from a revitalized Typhoon Nangka, which reached super typhoon status with 155 mph winds late last week before weakening to Category 1 strength over the weekend. Nangka is again looking impressive on satellite, with a very symmetric circulation and a double-eyewall structure now evident on water vapor imagery from the MTSAT satellite. This structure indicates an eyewall replacement cycle, after which Nangka will have ample time to strengthen further. Peak winds are estimated at 120 mph. Wind shear is low (5 – 10 knots) and there is plenty of oceanic heat content ahead of Nangka. Nangka is expected to follow a somewhat unorthodox path toward Japan: the typhoon has already recurved, now moving almost due northward at around 10 mph, but a ridge to its north is expected to strengthen and bend Nangka back toward the northwest. The latest JTWC forecast brings Nangka close to the threshold of super typhoon status by Wednesday night local time, with top sustained winds predicted to reach 125 knots (145 mph). The GFS and ECMWF models are both bullish on Nangka, keeping the cyclone close to its peak strength until just before landfall. This appears most likely to occur in or near Japan’s large western islands of Kyushu and Shikoku, with impacts possibly extending east toward Honshu and the large cities of Kyoto, Kobe, and Osaka, as noted by The Weather Channel’s Jon Erdman. As with the U.S. mid-Atlantic coast, most typhoons approaching Japan are moving toward the northeast. An approach from the southeast, more perpendicular to the coastline, would bolster Nangka’s destructive power, much as Hurricane Sandy’s unusual approach from the southeast in 2012 increased the damage it wreaked on New York and New Jersey.

Halola nears hurricane strength in Central Pacific
A record-smashing burst of activity continues over the Central Pacific as Tropical Storm Halola continues to gradually strengthen. Halola should reach hurricane strength by Monday night, making it one of the earliest central Pacific hurricanes on record in the NOAA database. The JWTC projects Halola to be a Category 3 storm by the end of the week, moving just south of Wake Island as a strong Category 2 hurricane. The last major hurricane to strike Wake Island was Ioke, which brought sustained winds estimated at 155 mph and a minimum central pressure measured at 934 mb on August 31, 2006. Elsewhere in the Central Pacific, Tropical Depression Iune is now dissipating over open water several hundred miles southwest of Hawaii. In the Eastern Pacific, we have two active named storms, neither of which is expected to hit land: Tropical Storm Enrique and Tropical Storm Dolores.

Figure 2. A conga line of tropical cyclones straddles the Pacific this morning on Weather Underground’s tropical cyclone home page.

Eric Blake (National Hurricane Center) and Phil Klotzbach (Colorado State University) called attention this weekend to some remarkable statistics. Since Thursday, we’ve seen three tropical storms develop in the central Pacific, all of which broke early-bird records in the period of reliable data that extends back to 1949:

Earliest tropical storm during hurricane season: Ela (July 9).
Previous record: Wali, July 17, 2014
2nd earliest tropical storm during hurricane season: Halola (July 11).
Previous record: Maka, Aug. 11, 2009
3rd earliest tropical storm during hurricane season: Iune (July 11).
Previous record: Moke, Sep. 4, 1984

Sea-surface temperatures over the central Pacific are substantially warmer than average, a result of the potent El Niño event that continues to intensify. This is allowing far more activity than usual over the basin, which does not usually host many hurricanes. The closest analog to this year’s record burst of central pacific activity is in 1982, just prior to the intense 1982-83 El Niño event. That year, the central Pacific saw a record total of four named storms for the season and a record three named storms in an 18-day period (that mark has been just broken with the three-day streak noted above). A powerful Madden-Julian Oscillation is moving across the central Pacific, likely adding to the very favorable conditions for tropical cyclone formation. According to NOAA’s weekly update (see PDF), the MJO is expected to remain in place or perhaps even retrogress over the next few days, which should help keep the central Pacific uncharacteristically active.

Update: Tropical Storm Claudette forms in northwest Atlantic
Disturbance 92L was upgraded to Tropical Storm Claudette by the National Hurricane Center at 1:00 pm EDT Monday, after ASCAT scatterometer data showed winds of tropical storm force within a well-defined circulation. Claudette's top sustained winds are now estimated at 45 knots (50 mph), with a center of circulation about 330 miles south-southeast of Nantucket, Massachusetts. Claudette is heading northeast at 15 mph, and its forward motion should increase over time. By Tuesday afternoon, wind shear will rise to a very high 25 - 30 knots and ocean temperatures will fall below 24°C, likely bringing Claudette below tropical storm strength no later than Wednesday morning.

Bob Henson and Jeff Masters


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