Priscilla Weakens to a Tropical Storm

Former Hurricane Priscilla weakened to a tropical storm over the Eastern North Pacific Ocean south of Baja California on Wednesday afternoon.  At 2:00 p.m. EDT on Wednesday the center of Tropical Storm Priscilla was located at latitude 21.7°N and longitude 112.7°W which put the center about 195 miles (310 km) west-southwest of the southern tip of Baja California.  Priscilla was moving toward the northwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 985 mb.

A Tropical Storm Watch was in effect for the portion of the coast from Cabo San Lucas to Cabo San Lazaro, Mexico.

Former Hurricane Priscilla rapidly weakened to a tropical storm south of Baja California on Wednesday.  Thunderstorms around the center of Priscilla’s circulation and in the northern half of the circulation weakened.  Bands in those parts of Tropical Storm Priscilla consisted primarily of showers and lower clouds.  Thunderstorms were still occurring in bands in the southern and western periphery of Priscilla’s circulation.  Weakening of the thunderstorms near the core of Tropical Storm Priscilla greatly reduced the upper level divergence.  With much less upper level divergence the inflow of mass in the lower levels of the atmosphere caused the surface pressure to increase.

The circulation around Tropical Storm Priscilla was still large.  Winds to tropical storm force extended out 160 miles (260 km) from the center of Priscilla’s circulation.

Tropical Storm Priscilla will move through an environment that will become even more unfavorable for intensification during the next 24 hours.  Priscilla will move over water where the Sea Surface Temperatures are near 26°C.  An upper level trough near the west coast of the U.S. will produce southwesterly winds that will blow toward the top of Priscilla’s circulation.  Those winds will cause the vertical wind shear to increase.  The effects of cooler water and increasing vertical wind shear will cause Tropical Storm Priscilla to continue to weaken during the next 24 hours.

Tropical Storm Priscilla will move around the western end of a high pressure system over Mexico.  The high pressure system will steer Priscilla toward the north-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Priscilla will move west of Cabo San Lazaro on Thursday.

Elsewhere over the Eastern North Pacific Ocean, Tropical Storm Octave continued to gradually weaken far to the southwest of Baja California.  At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Octave was located at latitude 15.4°N and longitude 116.2.°W which put the center about 660 miles (1065 km) southwest of the southern tip of Baja California.  Octave was moving toward the east at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1003 mb.