The low-level circulation that once was Ernesto has dissipated over western Mexico. However, the upper-level feature, showers and thunderstorms have survived the trip west. In fact, the satellite picture shows an impressive amount of cold top showers and thunderstorms along and off the west coast of Mexico. The patch of clouds near 20N120W is weakening Tropical Storm Gilma.
Most of the global mountains takes the upper-level system moving off the Mexico coast and gradually develops and intensifies a surface low pressure system that could easily become a tropical storm before the weekend is through.
If this happens, and there seems to be a good chance, it will have the new name, Hector.
While models take it west into early next week, a developing trough off the West Coast could turn this system north or even northeast. The GFS has this low directly affecting the southern and central Baja Thursday or so next week. The European has it somewhat farther west but not too far to the west of the southern Baja by the same time period.
This will make for a very hazardous period for firefighters into early Friday night.
With such high heat and low humidity, the fire danger will be as high as it can get.
For the second time this week, parts of northern California will get some rain.
With such high amounts of water vapor, thunderstorms will bring locally very heavy rain that can cause flash flooding.
Many areas east of the Cascades this weekend will be over 100 F.
some of the moisture from Andres and newly formed Blanca could influence the weather in the Southwest