Julio (2020)

A small tropical cyclone formed from the mid-level remnants of Atlantic Hurricane Nana. The system developed into Tropical Storm Julio by 0000 UTC 5 September 2020 about 75 nautical miles southwest of Puerto Ángel, Mexico, and moved west‑northwestward roughly parallel to the southern coast of Mexico. Julio reached its peak late on 5 to early 6 September and then gradually weakened under increasing wind shear, becoming a tropical depression by 0000 UTC 7 September near Socorro Island before dissipating later that day.

Julio did not make any landfalls on the Mexican mainland. Its center remained about 90 nautical miles offshore of southern Mexico while it moved west‑northwest. The circulation opened into a trough and remnants were absorbed about 200 nautical miles southwest of Socorro Island after dissipation; no coastal watches or warnings were required because the storm’s strong winds were confined to a very small area.

The storm’s maximum sustained winds peaked at 40 knots (46 mph) with a minimum central pressure of 1004 mb, corresponding to a weak tropical storm at its peak. The field of tropical‑storm‑force winds was small, extending only about 20 nautical miles from the center when first observed.

There were no reports of storm surge associated with Julio and no reported rainfall totals or flooding impacts in the NHC report. Because the storm stayed well offshore and was small, coastal tide and rain observations did not record notable surge heights or heavy accumulations tied to Julio.

No damage or casualties were reported in association with Julio. The regions nearest the track—southern coastal areas of Oaxaca, Guerrero, Colima, and Jalisco and the offshore Socorro Island area—experienced little to no impact from the cyclone.

Julio’s development was notable because it regenerated from remnants of an Atlantic hurricane and formed unexpectedly in the eastern Pacific; forecasts did not anticipate redevelopment until shortly before genesis. The storm’s small size contributed to forecast challenges and to unusually large track errors for the short forecast sample, although intensity forecast errors were near typical values.