Hernan (2008)

Hernan formed from a tropical wave that moved into the eastern North Pacific and became a tropical depression on 6 August 2008 about 675 nautical miles south-southwest of the southern tip of Baja California. It strengthened to a tropical storm early on 7 August and moved west to west-northwest while generally remaining well offshore. Hernan rapidly intensified beginning 8 August, became a hurricane that day, reached peak strength on 9 August, then weakened as it moved over cooler waters and became a remnant low by 13 August; the remnant low dissipated about 16 August roughly 400 nmi southeast of the Island of Hawaii.

Hernan did not make any landfalls. Its track remained over the open eastern North Pacific and well away from the Mexican coast and Baja California throughout its life.

The storm’s maximum sustained winds peaked at 105 knots (about 121 mph) at 1200 UTC 9 August, with a minimum central pressure of 956 mb. That peak intensity corresponds to a Category 3 hurricane on the Saffir–Simpson scale.

Because Hernan stayed over open water, there were no storm surge measurements tied to coastal impacts and no reported heavy rainfall totals over land in the report. No ships reported tropical-storm-force winds in association with Hernan.

There were no reported deaths or damage associated with Hernan. The regions closest to the storm remained unaffected, and no casualties or property impacts were recorded in the NHC report.

Noteworthy items include that Hernan underwent an eyewall replacement cycle around 9–10 August as it reached peak intensity and then began weakening over cooler ocean temperatures. The storm’s formation was not well anticipated—forecasters first explicitly mentioned possible tropical depression formation only about 12 hours before genesis—but track forecasts for Hernan were unusually accurate, with 4- and 5-day official track errors among the lowest for eastern Pacific storms since 2001.