Here is the latest Jack Coles signal report posted on September 14:

Last night about 9:30 PM
Jack got a main signal that was not very loud or clear.
Not sure. There are 2 possible scenarios:
Scenario 1: this could be an aftershock of the Napa Valley quake. It is
still within the 16 day window. Jack has never before gotten a main signal
for an aftershock. So this would mean it would be a larger aftershock than
the previous ones.
Scenario 2:
This could be a separate quake & fall into the usual window of 1-4-9-16
which would make it Sept. 15, 18, 23, or 30. This would be SOMEWHERE in
California. Jack did not know if this would be in Northern, Central, or
Southern CA. And it would be between 3.5 and a 4.