There is a strange signal appearing on the charts for the 9th December 2016 at: https://weather.gc.ca/ensemble/naefs/cartes_e.html
I seldom carry these past 120 hours are they are notoriously bad for forecasts.
But you can see the compression building up on this one, all along the eastern edge of the large cyclone in the west.
It last the full run at least so I can’t ay when it ends nor if it goes on past the spaghetti.
What ever the case I am still assuming that the way it points and the type of air mass between them indicate their likely epicentre to be in this side of the globe (Caucasian) as opposed to the Asian side (Indo-Chinese.)
This despite the presence of the Long High beside it and the pair of smaller ones on the other (north-eastern) side.
I haven’t seen (noticed) such a chart before so I am unfamiliar with them the only one missing from my collection as far as I know is the massive eruption chart. I would expect that chart to have a long run that is somewhat similar to the above.
And we have missed out on a couple or three massive earthquakes very recently as well as some much further back than I care to recall. Generally they tend to rob peter to pay Paul; just as the weather does.
Whatever the case, three well defined air masses of the same type in aa straight line indicates either an earthquake or a volcanic eruption. If it is a serial signal covering at least three charts midnight/noon/midnight or noon/midnight/noon it evolves as volcanic
If there is only the one signal, or at most two, then it indicates an earthquake.
Notice how many cyclones appear in the North Atlantic:
I don’t have anything to say about these. Generally with the NA-EFS a straight line indicates seismic volcanic activity.
A triangle or (more unusually a rhomboid) indicates storms.
High energy fields tend to attract anticyclones down from above, hence the lower temperatures associated with volcanism.
The presence of occluded fronts cold alternating with warmth running across the Atlantic indicate that volcanic activity takes place on the arrival of the front along the coast of Europe.
Cyclone that contain a spiral og warm fronts will evolve as earthquakes when the cyclone dissolves on the shoreline or in shallows.
Volcanic stuff tands to bounce off a shoreline as though throw away magnetically.
Such displays tend to enfold anticyclonic systems within them.
Alternatively they can divide into multiple cored smaller cyclones in which case some counter rotation tends to be present.
So now we wait.