One italian tanker out of Rome and two US tankers out of ?

On present headings they will meet in south-east Poland.

Tankers are interesting because they mean other airplanes are active near by (once they enter refueling loops). This could be fighters, bombers or ISR-planes.

Right now they are on their way, not actively refueling anyone by the looks of it.

And there, 4 tankers. A UK one joined.
Five tankers.

For reference, this is many times more than usual for a sunday.

My database that collects all signals from adsbexchange.com once an hour see between 25-50 occurences per day, or 1-2 per hour.

What we see now is 5 per hour by the same metric.

Nine tankers airborne over Europe, on a sunday.

If we include two A400's that operate both as tankers and cargo airplanes (hence hard to know their mission beforehand) we are now at 12 tankers.

Only one of them, HOBO13, has flown in an obvious refueling pattern.

The rest are either moving to new bases/maintenance or possibly ferrying other planes. Ie helping fighters and similar with smaller fuel tanks to move far.

Nevertheless, its a very large number for a sunday.