Lowell (2008)

Lowell formed from a tropical wave and a surface trough in the eastern Pacific and became a tropical depression on 6 September 2008 about 255 nautical miles south of Manzanillo, Mexico. It became a tropical storm early on 7 September and moved generally northwestward, reaching and holding its peak for about 18 hours while passing near Socorro Island. Shear and dry air later weakened Lowell; it turned north-northeast, weakened to a depression by 10 September, and its circulation opened into a trough on 11 September.

Lowell made landfall near Cabo San Lucas on the southern tip of the Baja California peninsula at about 0900 UTC on 11 September as a 30‑kt (about 35 mph) tropical depression. No other tropical cyclone landfalls were recorded; the system’s remnants produced weather impacts after it dissipated.

The storm’s maximum intensity was 45 knots (about 52 mph), with a minimum central pressure near 998 mb. That peak intensity was reached from 1200 UTC 7 September through 0600 UTC 8 September, when Lowell was closest to Socorro Island; its landfall intensity at Cabo San Lucas was about 30 kt (approximately 35 mph).

Storm surge reports in the official record are limited; however, two unofficial stations in Cabo San Lucas reported minimum pressures of 998.5 mb and 1000.6 mb as the center passed overhead. Heavy rainfall from Lowell’s remnants produced major totals in Mexico and the U.S.: in Sonora and Sinaloa the remnants caused severe flooding (see next paragraph), and in the central United States Wichita, Kansas measured 10.31 inches of rain on 12 September (a daily record), while Chicago O’Hare recorded 6.64 inches — the highest one‑day total since records began in 1871.

The flooding in Mexico’s states of Sonora and Sinaloa left more than 26,500 people homeless. Cities in Sonora most affected included Navojoa, Benito Juárez, Huatabampo, and Etchojoa. The government of Sonora estimated damage at about 200 million pesos (roughly 15.5 million USD). The report does not list confirmed storm‑related deaths attributable to Lowell.

Noteworthy details: Lowell’s initial development was not well forecast; post-analysis showed it had likely become a depression by the time it was first mentioned as a potential development in official outlooks. Official track errors were below average through 72 hours, and official intensity forecasts were generally better than long‑term averages, though some model guidance outperformed the official intensity forecasts at many lead times.