Tropical Cyclone • California • National Hurricane Center • Mexico

Hilary Remains A Powerful Category 4 Hurricane. Hurricane Warning Issued For Portions Of Baja California And Tropical Storm Watch Issued For Extreme Southern California.

8am PDT Fri Aug 18 Key Messages for Hurricane #Hilary: There is the potential for rare and dangerous flooding impacts from heavy rainfall across portions of the Southwestern U.S. this weekend.

Active Systems:

The National Hurricane Center is issuing advisories on Hurricane Hilary, located approximately 400 miles south of the southern tip of the Baja California peninsula.

South of Southern Mexico:

A broad area of low pressure could form offshore of the coast of southern Mexico early next week. Some gradual development of this system is possible thereafter while it moves slowly toward the west-northwest or northwest, generally parallel to the coast of southern and southwestern Mexico.

* Formation chance through 48 hours…low…near 0 percent.

* Formation chance through 7 days…low…30 percent.

1. Eastern Tropical Atlantic (AL98):

Showers and thunderstorms continue to show some signs of organization in association with a broad area of low pressure located a few hundred miles west of the Cabo Verde Islands. Environmental conditions appear generally favorable for additional development of this system, and a tropical depression is likely to form over the weekend while it moves toward the west-northwest or northwest at about 10 mph across the eastern tropical Atlantic. By early next week, upper-level winds over the system are forecast to increase, and further development is not expected.

* Formation chance through 48 hours…medium…60 percent.

* Formation chance through 7 days…high…70 percent.

2. Central Tropical Atlantic (AL99):

An elongated trough of low pressure located roughly halfway between the Cabo Verde Islands and the Lesser Antilles is producing some disorganized showers and thunderstorms. Environmental conditions are only marginally conducive for further development of this system, but a tropical depression could still form during the next couple of days while it moves west-northwestward at 10 to 15 mph across the central tropical Atlantic. Thereafter, upper-level winds are forecast to become unfavorable for any further development.

* Formation chance through 48 hours…medium…40 percent.

* Formation chance through 7 days…medium…40 percent.

3. East-Southeast of the Lesser Antilles:

Another area of low pressure could form in a day or so from an elongated trough of low pressure located several hundred miles to the east-southeast of the Lesser Antilles. Some slow development of this system is possible over the weekend and into early next week as it moves generally west-northwestward at 10 to 15 mph across the Lesser Antilles and into the northeastern Caribbean Sea.

* Formation chance through 48 hours…low…10 percent.

* Formation chance through 7 days…low…30 percent.

4. Western Gulf of Mexico:

An area of disturbed weather located just north of Hispaniola is forecast to move into the Gulf of Mexico by early next week, where a broad area of low pressure could form. Some slow development of this system is possible thereafter as it moves westward and approaches the western Gulf of Mexico coastline by the middle of next week.

* Formation chance through 48 hours…low…near 0 percent.

* Formation chance through 7 days…low…30 percent.