Greg (2005)

A small tropical cyclone formed from a tropical wave that crossed Central America and entered the eastern North Pacific in early August 2005. The system organized quickly and became a tropical depression at 0600 UTC on 11 August about 600 nautical miles south of Cabo San Lucas, Mexico. It strengthened to Tropical Storm Greg by 1200 UTC that day, tracked generally west to west‑northwest, slowed and meandered mid‑life, then turned southward and became nearly stationary. Greg weakened to a tropical depression late on 14 August and degenerated to a remnant low by 0000 UTC 16 August; the remnant low was absorbed into the Intertropical Convergence Zone within about a day.

Greg did not make landfall on Mexico or any other landmass. Its life and track remained well offshore of the Mexican coast, centered several hundred nautical miles southwest of Baja California throughout its existence, so no coastal watches or warnings were required.

The storm’s maximum sustained winds peaked at 45 knots (about 52 mph) and the minimum central pressure at peak was 1000 mb. At peak intensity (0000 UTC 12 August) Greg was a moderate tropical storm, well below hurricane strength.

Because Greg remained far from land, there are no reported storm surge measurements associated with the cyclone and no reports of rainfall totals from ships or land stations tied to the storm’s core. Satellite and remote-sensing data were used to monitor the storm; no buoys or ships reported observations from within Greg’s circulation.

There were no reports of deaths or damage associated with Greg. The impacts on coastal Mexico were negligible given the storm’s distance offshore.

Noteworthy points: Greg developed more rapidly than expected, with genesis occurring only about 14 hours after the system was first mentioned in Tropical Weather Outlooks. Forecast track errors through 48 hours were comparable to historical averages, but official intensity forecasts generally overestimated strengthening and had larger-than-average errors. The UK Met Office model performed relatively well in forecasting Greg’s slow motion.