Weather

It forecast a November–December peak above plus 3 degrees Celsius on a relative scale.

Why it mattersNOAA gives a 75% chance that October–December RONI reaches at least plus 2.5 degrees, a level historic since 1950.

Tropical Storm Hanna formed on September 28 as the basin's eighth named storm. The National Hurricane Center forecast the system to be short-lived, with reporting noting the Atlantic still had no hurricanes.

Why it mattersThe Atlantic usually sees its first hurricane around August 11, but a strengthening El Niño suppresses activity by increasing storm-limiting wind shear.

The National Hurricane Center expects Tropical Storm Rachel to strengthen into a hurricane by midweek. Meanwhile, Polo was forecast to hit the west coast of Baja California Sur on September 28 near major-hurricane strength.

Why it mattersScientists attribute the unusually busy Pacific storm activity to exceptionally strong El Niño conditions.

Late September 24, an NHC advisory placed Hurricane Nolo about 240 miles south of South Point, Hawaiʻi, with 80-mph sustained winds. The NHC forecast further strengthening.

Why it mattersHawaiʻi Island faces potentially catastrophic flooding alongside gusty winds and dangerous surf.