Norbert (2020)

A small area of low pressure that formed a few hundred miles south of Acapulco developed into Tropical Depression Norbert on 5 October 2020 about 550 nautical miles southwest of Acapulco. The system strengthened to a tropical storm later that day, reached an initial peak on 6 October, then weakened to a depression and opened into a trough around 10 October. The remnants moved northwest, redeveloped near Socorro Island and re-formed as a tropical depression on 13 October, became a tropical storm again on 14 October as it moved northwestward parallel to the Baja California Peninsula, and degenerated to a remnant low by 15 October before dissipating.

Norbert did not make any landfalls on the Mexican mainland or on Baja California during its life. Its re-formation and later motion took it just northwest of Socorro Island (re-formation on 13 October), and it passed well offshore while paralleling the west coast of the Baja California peninsula on 14 October, but no watches or warnings were issued and no coastal landfalls were recorded.

The storm’s maximum sustained winds peaked at 50 knots (about 58 mph) near 1200 UTC on 6 October, with an estimated minimum central pressure of 1000 mb. At peak intensity Norbert was a moderate tropical storm (below hurricane strength) and never reached tropical storm–force winds at land locations.

Observed storm surge and rainfall impacts were minimal to none in populated areas; the official report notes there were no reports of tropical-storm-force winds associated with Norbert and does not list any measured coastal surge values tied to the storm. Rainfall and surge measurements at named cities or counties were not reported in the NHC report, and no significant coastal inundation was recorded.

There were no reported deaths or damage attributable to Norbert. The most affected areas were offshore waters south of Mexico and near Socorro Island where the system formed and re-formed, but impacts to populated regions were negligible.

Noteworthy aspects include Norbert’s unusual life cycle: it weakened to a trough, later re-developed into a tropical cyclone near Socorro Island, and executed a small cyclonic loop while weak. Forecasting the storm proved difficult at times—track and intensity forecast errors were larger than recent averages for some periods—though the European model (ECMWF) and some regional hurricane models performed relatively well.