Tropical Storm Halola Makes Landfall in Mainland Japan, Weakens to Depression (FORECAST)

Nick Wiltgen
Published: July 26,2015
Tropical Storm Halola made landfall on the Japanese mainland Sunday evening after slashing through the Ryukyu Islands of southern Japan, hitting the largest of the Amami Islands directly after delivering only a glancing blow to Okinawa. It has since weakened to a tropical depression.
The Japan Meteorological Agency (JMA) said Halola made landfall near Sasebo city, Nagasaki prefecture, around 7 p.m. Japanese Standard Time (JST) Sunday. Maximum sustained winds at the time were estimated at 45 mph (20 meters per second).

Halola: Current Status and Infrared Satellite

JMA, in its final advisory on the storm, said Halola weakened to a tropical depression at 9 p.m. JST Sunday. Its remnants are expected to move near or over western Japan through Monday, bringing locally breezy conditions and some modest rainfall.
The Japanese Meteorological Agency has issued advisories for high waves generated from Halola for the Amami Islands and parts of the Japanese mainland. All warnings have been lowered.

Halola's Impacts So Far

Amami Airport on the island of Amami Ōshima reported a sustained wind of 70.7 mph (31.6 meters per second) at 12:15 a.m. local time on Sunday. Around the same time, the airport reported a peak gust of 89.7 mph (40.1 meters per second).
Tropical storm-force winds were also measured south of Amami Ōshima and just to the north of Okinawa on the islands of Okinoerabu and Tokunoshima, where sustained winds of at least 20 meters per second (44 mph) have been clocked.
Early Saturday morning, when Halola was still a typhoon, the island of Minamidaitō reported a sustained wind of 70.9 mph (31.7 meters per second). That is still the highest sustained wind reported on land due to Halola. The same island reported a peak gust of 97.8 mph (43.7 meters per second).
The center of Halola made its closest approach to Okinawa during the day Saturday, local time, passing east and northeast of that island. (Japan is 13 hours ahead of U.S. Eastern Daylight Time.)
On Okinawa, the peak sustained wind at Kadena was 31 mph Saturday afternoon, and the peak gust was 42 mph.
(FORECAST: Okinawa)

Halola Forecast

In an ironic twist, the tropical cyclone actually improved the weather over parts of Japan late this past week.
That's because it was extremely rainy earlier in the week in western parts of the mainland as well as the Ryukyu island chain, which includes Okinawa, south of the mainland. A persistent fetch of moisture-laden southwesterly winds, unrelated to the typhoon, dumped torrential rainfall on those areas.
The Japan Meteorological Agency says more than 600 millimeters (24 inches) of rain fell in 48 hours Monday and Tuesday on Nakanoshima, a small volcanic island in that chain. The village of Sata near the southern tip of Kyushu tallied 545.5 millimeters (21.48 inches) of rain in 72 hours Monday through Wednesday, with rain falling at a ferocious rate of 85 millimeters (3.35 inches) per hour at one point.
Interestingly, the wind circulation from Halola helped to disrupt that fetch of soggy air and replaced it with drier air on the outer periphery of Halola's core.

Rainfall Forecast

That said, Halola's core brought a renewed bout of heavy rain to the Ryukyu Islands. In particular, JMA's automated observation site at Isen, on the island of Tokunoshima, reported 114.5 millimeters (4.51 inches) of rain in one hour and 258.5 millimeters (10.18 inches) in three hours Saturday evening, both setting all-time records since that location began keeping weather records in 1977. That three-hour total broke the previous record by more than 4 inches.
The storm total rainfall there reached 444 millimeters (17.48 inches) in the 24-hour period ending 10:20 a.m. JST Sunday, setting a July record for 24-hour rainfall at that spot. About 7,500 people on the island were advised to evacuate, according to Japan's public broadcaster, NHK.
Most other areas being affected by Halola have reported less than half of those rainfall amounts, however. By late Sunday evening, most of Halola's rain was offshore, and land stations in western Japan were reporting no more than 8 millimeters (about 0.32 inch) of rain per hour.
Halola originated in the Central Pacific as a tropical depression on July 9. It became a tropical storm before crossing the International Date Line into the Western Pacific basin on July 12-13. It then reached typhoon strength July 14 through July 16 before weakening back to a depression by July 18. It returned to typhoon strength on July 21.
The U.S. military's Joint Typhoon Warning Center downgraded Halola from a typhoon to a tropical storm Saturday afternoon, and JMA followed suit Saturday evening.
Meteorologists Chris Dolce and Jonathan Erdman contributed to this report.
MORE: Typhoon Nangka, July 16-17, 2015