I am at 43N latitude. Yesterday was pretty windy (all day and into the evening) and the seeing forecast was not good. It was a series of gray blocks in both CSC and Astrospheric, but it was clear so I set up my 5" refractor on my deck. I didn't really plan for it so there was zero cool down time. I took a look and it wasn't that bad. GRS was around back, but I was seeing some decent detail in the bands. One of the moons was just off the face of the planet so I decided to hang around and see if it was going to go in front or behind the disc.
Best views were at about 200x. Jupiter is pretty big right now since we are days from opposition (been meaning to look up the exact angular size) so the image scale was pretty decent. As I was waiting to see how things would play out with the moon off the face, I noticed a dark spot in one of the equatorial belts. In moments of better seeing, that spot sharpened up into a small, perfect circle. Turns out another moon (Io) was crossing the planet as well. Twenty minutes later, the second moon (Ganymede) was crossing the planet. It had been a while since I lucked into a completely unknown-to-me double shadow transit.
I watched the spectacle for another 45 minutes or so with the refractor really getting acclimated and putting up stunning images. I was able to follow Ganymede onto the planet and see the disc easily, just ahead of the shadow. Kept trying to see Io on the face of the planet and maybe did a couple of times, but very fleeting and nothing I could hold long enough to say for sure even though the shadow of Io was very clear and distinct an visible 80%+ of the time. Being near opposition, the shadows are very close to the moons, but that still didn't help with Io. The size differences between the shadows of the two moons was very obvious. Ganymede was noticeably larger.
The moral of the story is . . . take a look. If it is clear and Jupiter is out, set something up and take a look. Who cares if it is too low in the sky this year or if the sky on a particular night doesn't look perfect? The more opportunities you give yourself the more you will see.