The way I determine severe quakes.
(1) I watch the Western Pacific Plate areas and use these to match against activity On the west coast of the Americas. I watch the Indian Ocean for the focus point of S and P Waves in California.

(2) I watch for minor earthquakes in areas where there is little or no activity and compare that against the frequency of major quakes that area.

(3) I was writing the Smithsonian about a major increase of earthquake activity from Long Valley Caldera to Calexico Mexico. This was over 1.5 to 2 years ago long before it happened.

(4) I have been awoken twice or more by earthquakes in this area and near Punt Gorda before they occurred. It is near to the area of my birth Fontana, CA.

(5) The time and magnitudes are estimates with the worst case number for magnitudes.

(6) I have noticed that some times I am ahead of professionals before they post.

(7) The current activity near Ridgecrest is similar to activity before the Landers and Hector quakes. Read post Coalinga and Parkfield

(8) My shoulders, knees and just a general strange feeling for closeness. At this time I am looking for a 7.0 quake before the 15th of February somewhere in the world. Probably the SW Pacific.

(9) Dreams.