Italian oddity

Quiet conditions have returned to the geomagnetic field over the past day or so.  Even so, there was a surprising spot at 14MHz WSPR overnight.

Curiously, IZ6QQT stopped being received at all from 23:30UT, but then reappeared in dramatic fashion between 01:40 and 01:50UT.  This is turning out to be a very narrow, well-defined and interesting time period for 14MHz WSPR reception at the moment.

I've drawn the plot as points only, because drawing lines between them 'fills in' in the gaps between them, giving a misleading portrayal of a decreasing signal when the signal is in fact absent:

14MHz reception of 2W 14MHz WSPR from IZ6QQT

There was only the usual quiet-conditions, daily undulation of the geomagnetic field last night, and the best fit for a restoration of the field from a very slightly disturbed local condition was the magnetometry output from Dickson, Russia (labelled 'dik' on the plot), with Tromso ('tro') also being close:

Somewhere at high latitudes, changes there bring this transient enhancement of signals from Italy.  Quite how is, to me anyway, a mystery, but it must involve effects that make their way to central European latitudes.  And why only one Italian station?  There are a large number of transmitters in operation, yet none are heard.