Hurricane Fernanda Slowly Weakens As It Moves West

Hurricane Fernanda weakened slowly as it moved farther west over the Eastern North Pacific Ocean on Sunday.  At 11:00 p.m. EDT on Sunday the center of Hurricane Fernanda was located at latitude 13.0°N and longitude 129.2°W which put it about 1440 miles (2315 km) west-southwest of the southern tip of Baja California.  Fernanda was moving toward the west-northwest at 12 m.p.h. (19 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. (220 km/h).  The minimum surface pressure was 960 mb.

Hurricane Fernanda completed at least one eyewall replacement cycle in which an outer eyewall formed around the original eyewall.  Eventually, the inner eyewall dissipated and a larger eye formed inside the outer eyewall.  The eyewall replacement cycle weakened Hurricane Fernanda when the stronger, inner eyewall dissipated.  Although Hurricane Fernanda is weaker, it is still a powerful hurricane.  There is a circular eye at the center of circulation.  A ring of strong thunderstorms still surrounds the eye and the strongest winds are occurring in that ring of storms.  Additional bands of showers and thunderstorms are revolving around the core of the circulation.  Thunderstorms in the core of Hurricane Fernanda are generating strong upper level divergence which are pumping out mass in all directions.

Hurricane Fernanda is moving over water where the Sea Surface Temperature (SST) is near 29°C.  The upper level winds are weak and there is little vertical wind shear.  Fernanda will gradually move over cooler SSTs.  When Fernanda moves over the cooler SSTs, it will extract less energy from the ocean and the hurricane will continue to weaken.  The weakening could occur very gradually because the wind shear is limited.

Hurricane Fernanda is moving south of a subtropical high pressure system which is steering the hurricane toward the west-northwest.  The subtropical high is expected to steer Fernanda toward the west-northwest during the next several days.