Tropical Storm Haishen (2008)

Tropical Storm Haishen was the twentieth officially recognized tropical storm of the 2008 Pacific typhoon season. The tropical depression that was to become Tropical Storm Haishen formed late on November 14, as a minor tropical depression to the south of the Ogasawara Islands, however the Japan Meteorological Agency (JMA) did not start issuing advisories on it until early the next day. As the JMA were starting to issue advisories on the minor tropical depression, the Joint Typhoon Warning Center (JTWC) reported that it was not expected to become a significant tropical cyclone within 24 hours as they anaylised the depression as subtropical. During that afternoon the JMA upgraded the depression to a full tropical depression while the JTWC issued a Tropical Cyclone Formation Alert on the developing depression as it had become Tropical. That evening, the JMA reported that the depression had become a tropical storm and named it as Haishen while the JTWC designated Haishen as Tropical Depression 25W. Early on November 16, the JTWC upgraded the depression to a tropical storm and then both the JMA and the JTWC declared it had reached its peak intensity with winds of 75 km/h (45 mph). At this time, the JTWC reported that there were signs in satellite imagery that Haishen had started its extratropical transition and then issued their final advisory 12 hours later. The JMA continued to issue advisories on Haishen for another 24 hours, when they declared that Haishen had become an extratropical low. The extratropical low then raced across the Pacific Ocean and crossed the International Dateline later that day. There were no casualties or Impact reported from Haishen as it remained out to sea throughout its life.

Meteorological history
On November 14, the JMA reported that tropical depression formed 490 km to the southeast of Iwo To, despite the JTWC noting the tropical cyclone formation was unlikely within the next 24 hours due to lack of deep convection. Later that day, deep convection began to persist near the center, indicating the storm developed a fully warm tropical core. Despite increased vertical wind shear, the JTWC issued a Tropical Cyclone Formation Alert on the system. During that evening, the JMA upgraded the depression to a tropical storm while the JTWC designated Haishen as a tropical depression. Early on November 16, Haishen attained its peak intensity of 75 km/h (45 mph). Traveling along the north portion of a subtropical ridge to the southeast of the system, dry air began to take toll on the system. The JTWC then issued their final warning later that day, as Haishen rapidly transitioned into an extratropical cyclone. The JMA followed suit 24 hours later. The extratropical low of Haishen accelerated towards the International Dateline, where it briefly reintensified.

Preparations, impact and naming
As Haishen remained out over open waters for the duration of its existence, there was no impact on any land-masses.

The name Haishen was submitted to the World Meteorological Organisation's Typhoon Committee by the People's Republic of China and was one of the original names submitted for use from January 1, 2000. The name Haishen is Chinese for the God of the sea and was last used in the 2002 Pacific typhoon season.