Hurricane Madeline was the final tropical cyclone of the 1998 Pacific hurricane season. Madeline originated from a tropical wave that emerged off the coast of Africa on September 25, 1998. The wave traversed the Atlantic Ocean and crossed over Central America on October 5 or 6. Gradually, the system intensified and was classified as a tropical depression on October 16, a tropical storm later that day, and a hurricane on October 17. The storm reached peak winds of 85 mph (140 km/h) about 95 miles (150 km) southwest of San Blas, Nayarit, and after 18 hours it subsequently began to weaken. Although Madeline never made landfall, numerous rainbands affected the Mexican coast causing no known damage or fatalities. The remnant moisture moved north and contributed to flooding in central Texas, which killed 31 people and caused $750 million (1998 USD) in damage.
During the afternoon, convective cloud tops warmed slightly although the storm continued to intensify. Soon after, thunderstorm activity became limited as Madeline remained generally stationary in movement. An approaching mid-level trough turned Madeline to the northeast. Banding features gradually improved in organization, and late on October 17 the storm attained hurricane status. However, satellite imagery indicated that convective activity was confined to the western portion of the storm, and at the same time an eye began to form. Early on October 18, data from a Reconnaissance aircraft flight into the storm found a minimum central pressure of 985 mb, as the storm was drifting to the northeast at around near the western edge of a large-scale east–west ridge axis. The apparent eye became cloud-filled shortly thereafter, and a slight increase in temperature was discovered near the center. Despite this, upper-level outflow was favorable, leading to predictions of slight intensification.
Shortly thereafter, Madeline attained peak winds of 85 mph (140 km/h) about 95 miles (150 km) southwest of San Blas, Nayarit. The hurricane maintained peak winds for about 18 hours while curving again to the northwest. With evidence of southern wind shear, only a small area of deep thunderstorm activity existed on October 19, and the system began to appear ill-defined of satellite imagery. The hurricane quickly weakened into a tropical storm, and by later that day, the storm became void of convection due to strong wind shear. On October 19, the storm was downgraded to a tropical depression, leaving just a swirl of low clouds midway between the southern tip of Baja California and mainland Mexico. By 0600 UTC on October 20, the remnants of Madeline had completely dissipated.
In anticipation of Madeline, the government of Mexico issued a tropical storm warning for the Baja California Peninsula southward from La Paz, and a hurricane warning from San Patricio, Jalisco to El Dorado, Sinaloa, including the Islas Marías. The storm was initially forecast to move ashore near Mazatlán, promting officials to close the city's port. President Ernesto Zedillo advised potentially affected residents to stay indoors or seek refuge in shelters. Also, the threat of the hurricane canceled a fishing expedition in the Sea of Cortez due to rough surf. The expedition was to provide a new aquarium in downtown Denver, Colorado with about 8,500 fish. Mexican authorities deployed 2,000 soldiers in remote areas of the Pacific coast state of Sinaloa to prepare for the hurricane. Several thousand residents and tourists at the resorts of Puerto Vallarta and Mazatlan were put on standby to evacuate their homes. Authorities along the coast in the state of Nayarit went house to house, advising people about the oncoming storm. In addition, ships from Salina Cruz to Acapulco were advised to stay in port.
Although Madeline never crossed the coast, numerous rainbands affected the Mexican coast, dropping up to . Despite this, no damage or fatalities were reported in Mexico. After the storm had dissipated, the remnant plume of moisture contributed to severe flooding in central Texas. Rainfall in Texas reached 22 inches (560 mm) in some locations. Thirty-one people died due to the flooding, and damage totaled to $750 million (1998 USD).