Tag Archives: Subtropical Depression Teresa

Sam Intensifies to a Major Hurricane

Hurricane Sam intensified to a major hurricane on Saturday morning. At 11:00 a.m. EDT on Saturday the center of Hurricane Sam was located at latitude 12.9°N and longitude 47.6°W which put it about 1095 miles (1760 km) east-southeast of the Northern Leeward Islands. Sam moving toward the west-northwest at 10 m.p.h. (16 km/h). The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 140 m.p.h. (225 km/h). The minimum surface pressure was 960 mb.

Hurricane Sam intensified to a major hurricane over the tropical Atlantic Ocean on Saturday morning. A well formed circular eye was present at the center of Hurricane Sam. The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Hurricane Sam. Storms near the core generated strong upper level divergence that pumped mass away from the hurricane in all directions.

The circulation around Hurricane Sam was relatively small. Winds to hurricane force extended out 25 miles (40 km) from the center of Sam. Winds to tropical storm force extended out 80 miles (130 km) from the center of circulation. The Hurricane Intensity Index (HII) for Hurricane Sam was 22.1. The Hurricane Size Index (HSI) was 7.4 and the Hurricane Wind Intensity Size Index (HWISI) was 29.5.

Hurricane Sam will move through an environment favorable for intensification during the next 24 hours. Sam will move over water where the Sea Surface Temperatures are near 28˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Hurricane Sam will continue to intensify during the next 24 hours. Sam could strengthen to Category 5 on the Saffir-Simpson Scale.

Hurricane Sam will move around the southern side of a subtropical high pressure system over the Atlantic Ocean. The high will steer Sam toward the west-northwest during the next few days. On its anticipated track Hurricane Sam could be east of the Northern Leeward Islands by the middle of next week.

Elsewhere over the Atlantic Ocean, former Subtropical Storm Teresa weakened north of Bermuda. At 11:00 a.m. EDT on Saturday the center of Subtropical Depression Teresa was located at latitude 34.3°N and longitude 65.0°W which put it about 140 miles (225 km) north of Bermuda. Teresa was stationary. The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h). The minimum surface pressure was 1009 mb.