Despite vertical wind shear caused by the outflow from Hurricane Andres, the low level circulation of Tropical Depression Two-E continued to consolidate and the National Hurricane Center upgraded the system to Tropical Storm Blanca.  At 11:00 a.m. EDT on Monday the center of Tropical Storm Blanca was located at latitude 13.5°N and longitude 104.1°W which put it about 335 miles (540 km) south-southwest of Zihuatanejo, Mexico.  Blanca was moving toward the northwest at 5 m.p.h. (7 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1004 mb.

Upper level divergence from Hurricane Andres, which is about 1000 miles west of Blanca, is still generating some vertical wind shear over the top of Blanca.  However, the strongest upper level outflow and wind shear is now several hundred miles north of the tropical storm.  As a result, Blanca has been able to efficiently extract energy from the upper ocean and it has generated many more thunderstorms in recent hours.  The circulation has developed spiral bands and an inner core of convection.  The strong thunderstorms near the core appear to be generating some upper level outflow which is pumping out mass and causing the surface pressure to decrease.  Blanca is over water where the Sea Surface Temperature is near 30°C and there is a lot of energy in the upper ocean.  Blanca is likely to intensify and it could intensify rapidly if the magnitude of the wind shear remains moderate or low.

Blanca is being steered slowly toward the northwest by a ridge over northern Mexico, but the steering currents are relatively weak.  The ridge is expected to strengthen during the week and steer Blanca toward the northwest or north-northwest.  On its anticipated track Blanca poses no immediate threat to Mexico.  However, it could approach Baja California or the western coast of Mexico later this week.