Explained: Tropical Storm Pena forms in the Pacific Ocean south of Hawaii

Tropical Storm Pena formed Friday in the Pacific Ocean, well south of the Hawaiian islands

Tropical Storm

A tropical cyclone with sustained winds between 39 and 73 mph, as referenced by the formation of Pena

National Hurricane Center

The Miami-based U.S. agency that issues advisories and tracks tropical cyclones

El Niño

A climate pattern mentioned as contributing to an active Pacific hurricane season

Watches or warnings

Official alerts issued when a storm poses a threat to land, none of which were in effect for Pena