Hurricane Beta - Meteorological History

Meteorological History

On October 21, a westward-moving tropical wave entered the Caribbean Sea. The wave quickly developed organized convection, indicating that a possible low pressure area had developed along the wave. Continued development led to the formation of Tropical Depression Twenty-Five (which would later be named Alpha). The wave continued to move towards the west, producing minimal shower and thunderstorm activity. Once in the southwestern Caribbean, the wave slowed, and convection gradually redeveloped on October 25. The next day, with continued organization, the National Hurricane Center (NHC) stated that a tropical depression could develop in the following day or two. At around 18:00 UTC, the NHC determined that Tropical Depression Twenty-Six had developed about 105 miles (170 km) north of the central cost of Panama.

Located within an area of weak vertical wind shear and warm sea surface temperatures, the depression intensified. By 06:00 UTC the next morning, the depression was upgraded to a tropical storm and given the name Beta by the NHC. Beta was slowly moving towards the north-northwest in response to a mid-tropospheric shortwave trough over the Gulf of Mexico and mid-tropospheric ridge to the northeast of the storm. Deep convection developed near the center of circulation, signifying a developing system. With favorable conditions for development, Beta was forecast to intensify into a hurricane before making landfall in central Nicaragua. An eyewall rapidly developed around the center of circulation, fuelling further intensification. With the formation of an eyewall and the compact size of the storm, rapid intensification was anticipated. By the end of October 27, maximum sustained winds around the center of Beta were estimated at 60 mph (95 km/h). An increase in wind shear caused a minor disruption of the storm's structure, briefly preventing strengthening.

After maintaining its intensity for 30 hours, the shear weakened, and Beta began to intensify again. Around 00:00 UTC on October 29, the storm passed near Providencia Island with winds of 70 mph (110 km/h), just below hurricane-status. At this time, the cyclone began to turn towards the west. Beta intensified into a hurricane several hours later, with winds of 80 mph (140 km/h), as an eye became pronounced on infrared satellite images. Located south of a weakness within the subtropical ridge, the hurricane's motion slowed to a westward drift. With the formation of an eye, the chances of rapid intensification reached 62%, and the storm could possibly become a major hurricane—a hurricane with winds of 111 mph (178 km/h) or higher—before landfall. Beta continued to intensify as convection deepened around the 11.5 mi (18.5 km) wide eye, strengthening into a Category 2 hurricane with winds of 105 mph (170 km/h).

After undergoing a brief period of rapid intensification from 18:00 UTC on October 29 – 06:00 UTC on October 30, the hurricane reached its peak intensity as a Category 3 hurricane with winds of 115 mph (185 km/h) and a minimum pressure of 962 mbar (hPa; 28.42 inHg). The storm also began to turn towards the south-southwest as it reached its peak intensity and its maximum size, with tropical storm-force winds extending out 60 mi (95 km) from the center. However, as it neared the coast, cloud tops around the eye began to warm, signifying weakening. Around 12:00 UTC on October 30, Beta made landfall in central Nicaragua near La Barra del Rio Grande with winds of 105 mph (170 km/h). After making landfall, the hurricane weakened to a tropical storm, with winds decreasing to 65 mph (100 km/h), as the structure of the storm began to deteriorate. Early on October 31, Beta weakened to a tropical depression and dissipated a few hours later over the mountains of central Nicaragua.