Bud Quickly Strengthens to a Hurricane

Former Tropical Storm Bud quickly strengthened into a hurricane on Sunday.  At 5:00 p.m. EDT on Sunday the center of Hurricane Bud was located at latitude 15.3°N and longitude 104.2°W which put it about 365 miles (590 km) south-southeast of Cabo Corrientes, Mexico.  Bud was moving toward the northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 987 mb.  The government of Mexico issued a Tropical Storm Watch for the portion of the coast from Manzanillo to Cabo Corrientes.

Hurricane Bud strengthened quickly and the circulation exhibited the structure of a hurricane.  An eye formed at the center of circulation, although the eye was obscured intermittently by clouds.  A nearly complete ring of thunderstorms surrounded the eye and the strongest winds were occurring in the ring of storms.  Bands of showers and thunderstorms revolved around the core of Hurricane Bud.  Most of the stronger rainbands were occurring in the eastern half of the circulation.  Winds near the core of Bud were generating upper level divergence which was pumping mass away from the hurricane.  The removal of mass allowed the pressure to decrease rapidly, which generated a stronger pressure gradient force and higher wind speeds.

Most of the stronger winds were occurring on the eastern side of Hurricane Bud.  Winds to hurricane force extended out about 25 miles (40 km) to the east of the center of circulation.  Winds to tropical storm force extended out about 150 miles (240 km) to the east of the center.  The large area of tropical storm force winds on the eastern side of Hurricane Bud is the reason the government of Mexico issued a Tropical Storm Watch for a portion of the west coast of Mexico.

Hurricane Bud will continue to move through a very favorable environment for several more days.  Bud will move over water where the Sea Surface Temperature is near 30°C.  Bud will move through a region where the upper level winds will be weak and there will be little vertical wind shear.  Hurricane Bud will strengthen more and it could intensify rapidly during the next day or two.  Bud could strengthen into a major hurricane on Monday or Tuesday.

Hurricane Bud is moving near the western end of a ridge over Mexico.  The ridge is steering Bud toward the northwest  and that motion is forecast to continue for another day or two.  Hurricane Bud is likely to move more toward the north when it reaches the western end of the ridge.  On its anticipated track the center of Hurricane Bud will remain west of the west coast of Mexico.  Bud could approach the southern end of Baja California in four days.

Even though the center of Hurricane Bud is likely to remain west of the west coast of Mexico, some of the outer rainbands could move over parts of western Mexico.  Bud could bring gusty winds to places near the coast.  In addition Hurricane Bud could drop locally heavy rain in those areas and flash flooding will be possible.  Bud is likely to weaken before it reaches Baja California, but it could also bring gusty winds and heavy rains to that region later this week.

Elsewhere, Tropical Storm Aletta continued to weaken over cooler water.  At 5:00 p.m. EDT on Sunday the center of Tropical Storm Aletta was located at latitude 16.6°N and longitude 115.7°W which put it about 575 miles (925 km) southwest of the southern tip of Baja California.  Aletta was moving toward the west at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1002 mb.