Hurricane Blanca turned toward the north-northwest on Saturday and it appears headed toward the west coast of Baja California.  At 11:00 p.m. EDT on Saturday the center of Hurricane Blanca was located at latitude 19.2°N and longitude 110.4°W which put it about 255 miles (415 km) south of Cabo San Lucas, Mexico.  Blanca was moving toward the north-northwest at 10 m.p.h. (17 km/h).  The maximum sustained wind speed was 120 m.p.h. (185 km/h) and there were gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 952 mb.  The Hurricane Intensity Index (HII) was 22.1, the Hurricane Size Index (HSI) was 20.2 and the Hurricane Wind Intensity Size Index (HWISI) was 42.3.  The government of Mexico has issued a Hurricane Watch for the portion of the coast from Cabo San Lucas to Santa Fe.  A Tropical Storm Warning has been issued for the portion of the coast from Loreto to Puerto San Andresito including Cabo San Lucas.  Tropical Storm Watches have been issued for the portions of the coast from Puerto San Andresito to Punta Abreojos and from Loreto to Mulege.

Hurricane Blanca intensified early on Saturday as it was moving over water where the Sea Surface Temperature (SST) was near 28°C.  It is currently over water where the SST is closer to 27°C and it will move over cooler water when it gets north of latitude 20°N.  As a result it will be unable to extract enough energy from the upper ocean to maintain its current intensity.  An upper level ridge over Mexico also seems to be generating some easterly winds near Blanca and those winds are responsible for vertical wind shear on the eastern half of the circulation.  The combination of shear and cooler SSTs should steadily weaken the hurricane on Sunday.  However, it has a well organized circulation and it will spin down relatively slowly.  The rate of weakening will increase once it moves over SSTs that are cooler than 26°C.  Blanca could still have hurricane force winds when it nears the southern tip of Baja California.

A mid-level ridge over Texas and northern Mexico and a trough over the southwestern U.S. are combining to steer Blanca toward the north-northwest.  That track should continue as long as the vertical structure of the hurricane remains intact.  As Blanca weakens over cooler water, the vertical integrity of the circulation will not be as strong.  Some storms that move just west of Baja California, as Blanca is forecast to do, have the upper portion of their circulation decouple from the lower level circulation.  In those cases the middle and upper level portions of the circulation continue to move northward across Baja California and into the southwestern U.S., while the low level circulation stalls and spins down west of Baja California.  On its anticipated track Blanca could bring some strong winds to portions of southern Baja California, but the greater risks are high waves and locally heavy rainfall that could produce flooding.