Hurricane Adrian (1999)

Hurricane Adrian

Category 2 hurricane (SSHWS/NWS)
Hurricane Adrian on June 20, 1999
Formed	June 18, 1999
Dissipated	June 22, 1999
Highest winds	1-minute sustained: 100 mph (155 km/h)
Lowest pressure	973 mbar (hPa); 28.73 inHg
Fatalities	6
Areas affected	Mexico
Part of the 1999 Pacific hurricane season

Hurricane Adrian was a tropical cyclone that caused widespread flash flooding while remaining offshore of Mexico. The first named storm and first hurricane of the season, Adrian developed on June 18, 1999 from a large area of disturbed weather to the southwest of the Mexican coastline. Later that day, Adrian strengthened into a tropical storm. Gradual strengthening followed, as Adrian had intensified into a hurricane early on June 20. Further strengthening occurred, and Hurricane Adrian peaked as a 100 mph (155 km/h) category 2 hurricane, later that same day. Maintaining this intensity for approximately 12 hours, Adrian rapidly weakened thereafter on June 21 while simultaneously slowing in forward movement. Strong wind shear and cooling water temperatures caused Adrian to weaken to a tropical storm late on June 21. Weakening of Tropical Storm Adrian continued, and on June 22, it had been downgraded to a tropical depression. Later on that same day, the National Hurricane Center declared that Tropical Depression Adrian had dissipated. Large waves and inland flash flooding from Hurricane Adrian resulted in six fatalities, with an unknown amount of damage.

A large area of disturbed weather meandered to the south of the Gulf of Tehuantepec for several days. Quickly showing signs of organization, a low-level circulation and banding features were visible on satellite imagery by June 16. Simultaneously, a tropical wave emerged from Africa on June 5 and crossed the Atlantic; it later moving in the vicinity of the developing cyclone. The tropical wave had merged with the developing cyclone, which resulted in enhanced convection.

It is estimated that Tropical Depression One-E formed on June 18 while centered approximately 225 miles (362 km) southwest of Acapulco, Guerrero in Mexico. Heading mainly west-northwest for much of its duration, and would also parallel the coast of Mexico while a tropical depression between 175-225 mi (282–362 km) offshore. Its forward direction to the west-northwest was due to an influence by a deep-layered ridge of high pressure over Mexico. Later on June 18, Tropical Depression One-E began to accelerate while strengthening into Tropical Storm Adrian. Thereafter being upgraded to a tropical storm, Adrian was upgraded to a hurricane on June 20 while centered 420 mi (676 km) south-southeast of the southern tip of Baja California. Further strengthening of Hurricane Adrian occurred that same day, and Adrian had become a category 2 hurricane. Simultaneously to becoming a category 2 hurricane, Hurricane Adrian attained its peak intensity with winds of 100 mph (155 km/h) and a minimum pressure of 973 mbar (hPa; 28.73 inHg).