Typhoon Nangka is seen from Japan’s Himawari-8 satellite as it approaches the country. Nangka has journeyed an incredible 4,000 miles over 12 days. (Japan Meteorological Agency)

Typhoon landfall is imminent in Japan as Nangka churns northwest through the Pacific, threatening torrential rainfall and dangerously high waves.

Typhoon Nangka is steadily approaching the southeast coast of Japan with sustained winds of 85 mph — the equivalent of a category 1 hurricane. The typhoon has had a long history in the Pacific Ocean, born on July 3 as a tropical depression before blossoming into a fully-fledged typhoon three days later.

Track forecast for Typhoon Nangka. (Joint Typhoon Warning Center) Track forecast for Typhoon Nangka. (Joint Typhoon Warning Center)

As the storm tracked over 4,000 miles westward through the Pacific Ocean, it was able to take advantage of very warm sea surface temperatures and incredibly favorable atmospheric conditions to steadily gain strength. Nangka surged to the status of super typhoon a week ago when it peaked at sustained winds of 155 mph as it passed north of Guam. The storm maintained category 4 intensity for nearly three days.

Since then, Nangka weakened as it turned north — good news for Japan, though the typhoon’s potential impacts remain dangerous. Typhoon Nangka is expected to make landfall near the prefecture capital of Kochi overnight on Thursday, local time. The storm will bring winds of around 80 mph to the coastline of the Kochi and Tokushima prefectures, with much higher gusts possible in the higher terrain. Kochi’s capital city is home to a population of around 340,000 people.

Forecast radar for Typhoon Nangka as it makes landfall in Japan on Thursday evneing, local time, from the HWRF hurricane model. (tropicaltidbits.com) Forecast radar for Typhoon Nangka as it makes landfall in Japan on Thursday evneing, local time, from the HWRF hurricane model. (tropicaltidbits.com)

Forecast models are generating over a foot of rainfall in Japan where the typhoon is forecast to make landfall. The coastline in this region is mountainous with peaks that climb up to 4,000 feet, which will act to wring out the typhoon’s moisture as the air rises rapidly and condenses over the terrain. The HWRF hurricane model is forecasting rainfall totals in excess of 18 inches in the mountains of Kochi and Tokushima, where Nangka’s strongest winds are expected to come ashore. The Japan Meteorological agency has issued a yellow advisory for the prefectures in the path for winds and storm surge, and a red advisory for large waves.

Last week, Typhoon Nangka was the third in a train of typhoons that was tracking west across the Pacific Ocean — another remarkable event in what has turned out to be a record-breaking season. The strengthening El Nino in the tropical Pacific is creating a favorably toasty environment for tropical cyclones to form, and the season is boasting the numbers to prove it.

By July 12, the 2015 typhoon season in the Pacific Ocean had surpassed the previous record of 2004 in terms of accumulated cyclone energy — a measurement used to quantify the activity of hurricanes and typhoons during a season. Though typhoons in this region can form at any point during the year (there’s no official season like the Atlantic), tropical activity tends to increase between June and November. But by the end of May this year, three category 5-equivalent super typhoons had already formed.

With ocean temperatures continuing the skyrocket in the region, and four solid months of typhoon potential left, this season could blow the previous record out of the torrid water.