A side effect of this is that when Sporadic-E (Es) propagation occurs at the critical point along that path, the effect is obvious.
I was only commenting to two local friends two days ago that this year's Sporadic-E season seems to be late in starting, and my friends were in agreement with that statement.
This morning's events though took an interesting turn at 0906 GMT when the path from Ostrava in the Czech Republic was suddenly enhanced by a burst of Es which lasted for around ten minutes.
The frequency used by the Ostrava TV transmitter is 49.76MHz, just below the amateur "six metre" allocation.
(above) R_Meteor Trace of first Es Opening
SpectrumLab Trace of Es Opening (note +/- 25Hz Sidebands)
By a bizarre coincidence, as I type this entry, I have just heard a Spanish station EA3FER calling CQ in CW on 50.092MHz and shortly after another Spanish station, this time an EA6 call from the Balearics, so it appears that the 6-metre Es season has finally started!