Hurricane Rosa (2018)

Hurricane Rosa

Hurricane Rosa at peak intensity southwest of Baja California Sur on September 28
Meteorological history
Formed	September 25, 2018
Remnant low	October 2, 2018
Dissipated	October 3, 2018
Category 4 major hurricane
1-minute sustained (SSHWS/NWS)
Highest winds	150 mph (240 km/h)
Lowest pressure	936 mbar (hPa); 27.64 inHg
Overall effects
Fatalities	3 total
Damage	$50.5 million
Areas affected	Baja California Peninsula, Northwestern Mexico, Southwestern United States
IBTrACS / [1]
Part of the 2018 Pacific hurricane season

Hurricane Rosa brought widespread flooding to northwestern Mexico and the Southwestern United States in late September 2018, and was the first tropical cyclone to make landfall in Baja California since Nora in 1997. The seventeenth named storm, tenth hurricane, and seventh major hurricane of the 2018 Pacific hurricane season; Rosa originated from an Atlantic tropical wave that crossed the West African coast on September 6. The wave proceeded westward across the Atlantic, traversing Central America before entering the Gulf of Tehuantepec on September 22. There, the weather system acquired cyclonic features and became a tropical storm on September 25. Within a favorable atmosphere, Rosa entered a period of rapid intensification on September 27, peaking as a Category 4 hurricane with maximum sustained winds of 150 mph (240 km/h) a day later. Over the next few days, Rosa turned north and then northeast while steadily weakening, making landfall in Baja California as a tropical depression on October 2. After crossing over into the Gulf of California, the remnant system split apart and merged with an upper-level low off the coast of California by October 3.

Rosa prompted the issuance of tropical storm watches and warnings along the coast of Baja California, as well as various flood watches and warnings throughout the Southwestern United States. The impact of Rosa was relatively minor, as a combination of wind shear and cooler seas had weakened the storm significantly by the time it made landfall. Widespread flooding throughout northwestern Mexico, mainly in Sonora and Baja California, led to one drowning and minor damage. In Arizona, rainfall peaked at 6.89 in (175 mm) and caused flash floods that killed two people. Flood damage from Rosa and its remnants totaled $50 million (2018 USD) in the Southwestern United States and $530,000 in Baja California.