Hurricane Gabrielle strengthened to Category 4 on the Saffir-Simpson Scale east of Bermuda on Monday afternoon. At 5:00 p.m. EDT on Monday the center of Hurricane Gabrielle was located at latitude 31.7°N and longitude 61.8°W which put the center about 180 miles (290 km) east-southeast of Bermuda. Gabrielle was moving toward the north-northeast at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 140 m.p.h. (225 km/h) and there were wind gusts to 165 m.p.h. (265 km/h). The minimum surface pressure was 948 mb.
Hurricane Gabrielle strengthened to Category 4 on the Saffir-Simpson Scale east of Bermuda on Monday afternoon. A circular eye with a diameter of 20 miles (32 km was at the center of Gabrielle’s circulation. The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the center of Gabrielle’s circulation. Storms near the center of Gabrielle generated upper level divergence that pumped mass away from the hurricane. The removal of mass caused the surface pressure to decrease.
The size of the circulation around Hurricane Gabrielle increased on Monday. Winds to hurricane force extended out 40 miles (65 km) from the center of Gabrielle’s circulation. Winds to tropical storm force extended out 140 miles (225 km) in the western side of Hurricane Gabrielle. Winds to tropical storm force extended out 70 miles (110 km) in the eastern side of Gabrielle’s circulation.
The Hurricane Intensity Index (HII) for Hurricane Gabrielle was 28.6. The Hurricane Size Index (HSI) was 13.1 and the Hurricane Wind Intensity Size Index (HWISI) was 41.7.
Hurricane Gabrielle will move through an environment that will become unfavorable for intensification during the next 24 hours. Gabrielle will move over water where the Sea Surface Temperatures are near 28°C. It will move under the southern extent of the upper level westerly winds in the middle latitudes. Those upper level westerly winds will cause the vertical wind shear to increase. Hurricane Gabrielle will start to weaken when the wind shear increases.
The upper level westerly winds in the middle latitudes will steer Hurricane Gabrielle toward the east during the next 24 hours. On its anticipated track, Hurricane Gabrielle will move away from Bermuda on Tuesday. Gabrielle will approach the Azores on Thursday.
