Computer modeling is uncertain about the exact track of Carlotta -- with some guidance suggesting the storm's center moves onshore tonight while other guidance has the storm center veering a bit more westward this evening and tonight, keeping the storm's eye off the coast but continuing to pound portions of Mexico with torrential rainfall. Should Carlotta make landfall, it will quickly weaken as the terrain just inland from the Pacific coastline is rather mountainous...and that rough terrain will quickly tear the storms's circulation apart and weaken it into simply a heavy rainmaker for the mountains.
Regardless of course, Mexico will be picking up quite a bit of rain tonight through Sunday as this storm moves close to...if not inland on...the Mexican coastline. The National Hurricane Center is projecting as much as fifteen inches of rain in some areas from the storm, with three to five inches common.
More: Wunderground tropical page