Hurricane Adrian (2005) - Meteorological History

Meteorological History

Hurricane Adrian originated from a tropical wave that moved off the western coast of Africa, near the Cape Verde Islands in early May 2005. Between May 10 and 14, several areas of disturbed weather moved across Central America, contributing to the development of a broad area of low pressure about 520 mi (835 km) south-southeast of Acapulco, Mexico. On May 15, another tropical wave interacted with the low, resulting in the consolidation of the system. The following day, the developing low was nearly stationary as convection increased. Around 11:00 am PDT (1800 UTC) on May 17, the National Hurricane Center (NHC) estimated that the system developed into a tropical depression, the first of the 2005 Pacific hurricane season. Upon forming, the depression was situated just south of 10°N, making it the 40th known tropical cyclone to do so since 1949. Unlike most storms in the eastern Pacific, Tropical Depression One-E tracked towards the northwest in response to a trough over Mexico. Tropical cyclone forecast models at the time anticipated intensification as conditions ahead of the system favored tropical cyclone development. Initially, the system moved at a slow pace of 5 mph (8.0 km/h); however this later increased to 9 mph (14 km/h). Within six hours of being declared a depression, the cyclone was classified as Tropical Storm Adrian.

Over the following days, gradual strengthening took place as Adrian moved through a region of moderate wind shear. By May 18, deep convection consolidated around the center of circulation and feeder bands developed along the periphery of the storm. Warm waters, around 30 °C (86 °F), ahead of the storm would allow for further strengthening despite wind shear and interaction with the high terrain of Central America. Additionally, some forecasts predicted that Adrian would survive the passage of Central America and enter the Caribbean Sea, possibly becoming the third known storm to cross from the eastern Pacific into the Atlantic basin. By May 19, the storm became relatively disorganized and Adrian only maintained a small area of convection around its center. However, within hours of this disorganization, the system rapidly consolidated and satellite imagery depicted the precursor to an eye forming. Following this, Adrian intensified to a minimal hurricane before attaining its peak intensity around 10:00 am PDT (1700 UTC) on May 19. At this time, the storm was situated about 85 mi (140 km) and had sustained winds of 80 mph (130 km/h) and a barometric pressure of 982 mbar (hPa; 29 inHg).

Not long after becoming a hurricane, Adrian suddenly succumbed to persistent wind shear off the coast of El Salvador. Operationally, this weakening was not noticed by the NHC, leading to their assessment of the storm making landfall in El Salvador around 11:00 pm PDT (0600 UTC on May 20) as a Category 1 hurricane on the Saffir–Simpson Hurricane Scale. In post-storm analysis, it was determined that the center of Adrian never actually crossed the coastline of El Salvador. Rather, convection associated with the system was sheared northward away from the center of circulation. Meteorologists at the NHC stated that Adrian's near-parallel track along the coast of El Salvador contributed to its rapid weakening as well as keeping the low offshore. Later on May 20, the system weakened to a tropical depression and made landfall in Honduras, along the Gulf of Fonseca, around 1:00 pm PDT (2100 UTC) with winds of 25 mph (35 km/h). Several hours later, Adrian dissipated over the mountains of Central America.