| Category 1 hurricane (SSHS) | |
|---|---|
| Hernan at peak intensity | |
| Formed | September 30, 1996 |
| Dissipated | October 4, 1996 |
| Highest winds | 1-minute sustained: 85 mph (140 km/h) |
| Lowest pressure | 980 mbar (hPa; 28.94 inHg) |
| Fatalities | 1 direct |
| Areas affected | Mexico |
| Part of the 1996 Pacific hurricane season | |
Hurricane Hernan was sixth tropical cyclone to strike Mexico at hurricane intensity in the year 1996. The thirteenth tropical cyclone, eighth named storm, and fifth hurricane of the 1996 Pacific hurricane season, Hernan developed as a tropical depression from a tropical wave to the south of Mexico on September 30. The depression quickly strengthened, and became Tropical Storm Hernan later that day. Hernan curved north-northwestward on the following day, before eventually turning north-northeastward. While offshore of Mexico on October 2, Hernan intensified a hurricane. Six hours later, Hernan peaked as an 85 mph (140 km/h) Category 1 hurricane. The storm weakened slightly thereafter, and by 1000 UTC on October 3, Hernan made landfall in Barra de Navidad, Jalisco with winds of 75 mph (120 km/h). Only two hours later, Hernan weakened to a tropical storm. By October 4, Hernan weakened to a tropical depression, and dissipated over Nayarit on the following day.
The storm dropped heavy rainfall along the west coast of Mexico, with some areas experiencing over 15 inches (380 mm) of precipitation. As a result of the large amounts of rain, Hernan caused significant flooding, especially between Puerto Vallarta, Jalisco and Manzanillo, Colima. Flooding from the storm washed-out highways, disrupted telephone service, caused power outages, and damaged at least 1,000 homes in relatively sparsely-populated area of Mexico. In addition, there were at least 100 injuries, though no fatalities were reported. After dissipating, the remnants caused flooding in southern Texas, and one person was presumed to have drowned.
Contents |
A tropical wave emerged off the west coast of Africa in mid-September and moved westward crossed the Atlantic Ocean. Though convection associated with the system increased on two separate occasions, the tropical wave did not develop further. After emerging into the Pacific Ocean, deep convection began to consolidate while the system was in the Gulf of Tehuantepec on September 28. The cloud pattern improved, and by late on September 29, classifications began on the system via the Dvorak technique. By 0600 UTC on September 30, satellite imagery indicated that Tropical Depression Eleven-E developed while centered over 288 miles (463 km) south-southeast of Acapulco.[1] Three hours later, the National Hurricane Center initiated advisories on the depression, and noted that it was over warm sea surface temperatures and outflow was becoming well-established. As a result, it was predicted that the depression would intensify into a hurricane before October 3.[2]
Later on September 30, satellite intensity classifications estimated wind speeds of at least 40 mph (65 km/h). As a result, the National Hurricane Center upgraded the depression to Tropical Storm Hernan.[3] By October 1, the center of Hernan became difficult to location on infrared satellite imagery. As a result, the National Hurricane Center no longer anticipated that Hernan would intensify into a hurricane.[4] Later that day, Hernan strengthened slightly, while visible satellite images indicated that the center of the storm redeveloped.[5] Most of the computer models predicted that Hernan would parallel the coast of Mexico, while the GDFL noted that the storm would turn sharply northward and eventually make landfall in Mexico.[6] Early on October 2, deep convection began wrapping around the center, and it was noted that an eye feature was possibly forming. In addition, Hernan also developed very cold cloud tops while tracking slowly to the northwest.[7]
At 0600 UTC on October 2, it is estimated that Hernan intensified into a hurricane.[1] Operationally, Hernan wasn't upgraded to a hurricane until 1500 UTC.[8] The storm strengthened slightly further, and at 1200 UTC, Hernan attained its peak intensity with maximum sustained winds of 85 mph (140 km/h) and a minimum pressure of 980 mbar (29 inHg).[1] By late on October 2, radars began tracking the storm, and it was noted that the northern eye wall was affecting portions of the west coast of Mexico.[9] Shortly thereafter, the eye of Hernan became indistinct on satellite images, though it was still visible on radars in Mexico.[10] By 0900 UTC on October 3, it was noted that a radar in Cuyutlán, Colima indicated that Hernan executed a cyclonic loop to the southwest of Manzanillo.[11] About an hour later, Hernan made landfall near Barra de Navidad, Jalisco with winds of 75 mph (120 km/h).[1]
Hernan rapidly weakened inland, and it was estimated that it had weakened to a tropical storm only two hours after landfall. By 0000 UTC on October 4, Hernan weakened further, and was downgraded to a tropical depression.[1] Shortly thereafter, Hernan re-emerged into the Pacific Ocean, and the National Hurricane Center noted that possibility for the depression to restrengthen into a tropical storm.[12] Hernan weakened further as a large portion of its circulation remained on land, while the low-level center became difficult to locate.[13] By 2100 UTC, satellite images and surface reports indicated that Hernan degenerated into a broad area of low pressure.[14] It is estimated that Hernan dissipated at 0000 UTC on October 5 while centered over Nayarit.[1]
A tropical storm warning was issued from Acapulco, Guerrero to Manzanillo, Colima at 1800 UTC on October 1. Early on the following day, a hurricane watch was put into effect from Zihuatanejo, Guerrero to Manzanillo, Colima. Three hours later, the watch was upgraded to a hurricane warning. At 1500 UTC on that same day, a tropical storm warning was issued from Manzanillo, Colima San Blas, Nayarit. By 0300 UTC on October 3, the hurricane warning was extended from Cabo Corrientes, Jalisco to San Blas, Nayarit; the tropical storm warning was also extended, and included areas between Mazatlán, Sinaloa and San Blas, Nayarit.[1] As the storm rapidly weakened inland, all watches and warnings in effect were discontinued by 1500 UTC on October 3.[15]
Because the storm made landfall in a sparsely populated area, Hernan killed no one.[1] However, a boy was swept away and reported as missing after three rivers flooded in Veracruz.[16] Flooding occurred in Melaque, Jalisco, causing inches of rain in the area. Flooding also caused washed-out roads along Mexico Route 200 and 80. In many areas, telephone service was interrupted and power outages occurred. Around 1,000 homes were damaged or destroyed and 100 people were injured. Along the coasts of Colima and Jalisco, waves caused by Hernan reached 13 ft (3.9 m) in height.[1]
After dissipating, the remnants of Hernan brought heavy downpours to southern Texas. Rainfall reached 5.5 inches (140 mm) in Brownsville, which caused street flooding and forced several families to evacuated their homes. In addition, coastal flooding was reported in the town of South Padre Island.[17] As a result of heavy rainfall, a flash flood watch and warning was issued for Cameron, Hidalgo, Kenedy, and Willacy Counties.[18] One boy in Brownsville was classified as missing and presumed to have drowned.[19]