With the last 4.2 quake in San Bernardino and Fontana, Southern California Weather Force went full Earthquake Watch. There is now cause for scientific reasoning behind the fact a larger quake will hit California before February 8th.
There is an area in Northern California, north of San Francisco, called The Geysers. Usually when they are disturbed, it means pressure within the mantle is acting on the crust. We have seen 4s and 3s there in swarms. This pressure means that within the timing stated, the state of California will get a larger quake than 4.0.
The focus is the state, but we have seen quakes through the Cajon Pass within the last month. Both The San Andreas and San Jacinto Fault will be a focus spot. Once the Geysers talk, it means a stronger one is coming for the state. Wherever you are in California is where it could happen. It just means and proves the stress under the crust is there and working for a larger quake. You could be in Northern, Central, Southern California and Baja, but one thing is for certain, it is showing signs of pressure down there.