Hurricane Hilary Moves Toward Baja California

Hurricane Hilary was moving toward Baja California on Saturday morning. At 8:00 a.m. EDT on Saturday the center of Hurricane Hilary was located at latitude 21.5°N and longitude 113.4°W which put it about 490 miles (790 km) south-southeast of Punta Eugenia, Mexico. Hilary was moving toward the north-northwest at 13 m.p.h. (21 km/h). The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 155 m.p.h. (250 km/h). The minimum surface pressure was 943 mb.

A Hurricane Warning was in effect for the portion of the coast from Punta Abreojos to Cabo San Quintin, Mexico. A Hurricane Watch was in effect for the portion of the coast from Cabo San Quintin to Ensenada, Mexico. A Tropical Storm Warning was in effect for the portion of the coast from Punta Abreojos to Guaymas, Mexico. The Tropical Storm Warning included Cabo San Lucas. A Tropical Storm Warning was in effect for the portion of the coast from the U.S. border with Mexico to the Point Mugu, California. The Tropical Storm Warning included San Diego. The Tropical Storm Warning also included Catalina Island. A Tropical Storm Warning was in effect for the portion of the coast from Cabo San Quintin, Mexico to the border with the U.S. A Tropical Storm Watch was in effect for the portion of the coast from Guaymas to Huatabampito, Mexico.

Hurricane Hilary was moving closer to Baja California on Saturday morning. An eye with a diameter of 30 miles (50 km) was at the center of Hilary’s circulation. The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Hurricane Hilary. Storms near the core generated upper level divergence that pumped mass away from the hurricane.

The circulation around Hurricane Hilary was large. Winds to hurricane force extended out 50 miles (80 km) from the center of Hilary’s circulation. Winds to tropical storm force extended out 265 miles (425 km) from the center of circulation. The Hurricane Intensity Index (HII) was 25.1. The Hurricane Size Index (HSI) was 19.2 and the Hurricane Wind Intensity Size Index (HWISI) was 44.3. Hurricane Hilary was capable of causing regional major damage.

Hurricane Hilary appeared to be starting to weaken on Saturday morning. Thunderstorms were weakening in bands in the western side of Hilary’s circulation. Some of the bands in the western part of Hilary consisted primarily of showers and lower clouds. Northerly winds in the western half of Hurricane Hilary were pulling cooler, drier air into that part of the hurricane.

Hurricane Hilary will be moving into an environment that will become unfavorable for a major hurricane during the next 24 hours. Hilary will move over water where the Sea Surface Temperatures are cooler than 27°C. It will move between an upper level ridge over Mexico and the south central U.S. and an upper level low west of California. The upper level ridge and upper level low will interact to produce northerly winds that will blow toward the top of Hilary’s circulation. Those winds will cause the vertical wind shear to increase. The combination of cooler water and more vertical wind shear will cause Hurricane Hilary to weaken during the next 24 hours.

The upper level ridge over the south central U.S. and the upper level low west of California will steer Hurricane Hilary toward the north-northwest during the next 24 hours. On its anticipated track, the center of Hurricane Hilary will approach Punta Eugenia on Saturday night. Hilary will bring strong, gusty winds and locally heavy rain to Baja California. Heavy rain is likely to cause flash floods in some locations.

Hilary will reach southern California on Sunday. Hilary is likely to weaken to a tropical storm before it reaches southern California. Hilary bring strong winds and locally heavy rain to parts of southern California. Heavy rain is likely to cause flash floods in some locations. Flood Watches have been issued for parts of southern California, southern Nevada, southern Utah and western Arizona. Hilary could also bring strong winds to mountains in southern Nevada, southern Utah and western Arizona.