Ophelia Strengthens to Major Hurricane South of the Azores

Hurricane Ophelia strengthened into a Category 3 hurricane on the Saffir-Simpson Scale on Saturday morning as it moved south of the Azores.  That made Ophelia a major hurricane.  At 11:00 a.m. EDT on Saturday the center of Hurricane Ophelia was located at latitude 34.8°N and longitude 26.6°W which put it about 220 miles (355 km) south of the Azores.  Ophelia was moving toward the northeast at 25 m.p.h. (40 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 135 m.p.h. (220 km/h).  The minimum surface pressure was 960 mb.

It is very unusual to have such a strong hurricane near the Azores, but Ophelia contains all of the elements of a major hurricane.  There is a circular eye at the center of circulation.  The eye is surrounded by a ring of strong thunderstorms and the strongest winds are occurring in that ring of storms.  Well formed rainbands exists in the outer portions of the circulation.  Storms in the core of Ophelia are generating upper level divergence which is pumping mass away to the northeast of the hurricane.  Winds to hurricane force extend out about 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extend out about 125 miles (205 km) from the center.

Hurricane Ophelia is moving over water where the Sea Surface Temperature is near 25°C.  Normally, water at that temperature would be considered to be too cool to support the development of a major hurricane.  However, the temperature of the air in the upper troposphere is also cool and so the atmosphere is unstable enough to allow for the development of deep convection.  An upper level trough west of Ophelia is producing southwesterly winds which are blowing toward the top of the circulation.  There are also southwesterly winds in the lower and middle levels of the atmosphere and so the vertical wind shear is not strong enough to inhibit intensification

Hurricane Ophelia will be moving over cooler water and it is likely to weaken gradually during the next several days.  When Ophelia moves over the cooler water it will make a transition to an extratropical cyclone.  The size of the circulation will increase during the transition.  Hurricane Ophelia will evolve into a large very powerful extratropical cyclone during the next several days.

The trough west of Ophelia is steering the hurricane toward the northeast.  Hurricane Ophelia is expected to turn more toward the north during the next two or three days.  On its anticipated track Hurricane Ophelia will pass east of the Azores later today.  The strong extratropical cyclone that Ophelia will transition into could approach Ireland and the United Kingdom by Monday morning.  That cyclone will bring very strong winds and heavy rain to that region.