I'm having a similar issue with all the rain-lots of cracking tomatoes, and even some hail! I noticed I had a cherry-sized tomato that was cracked and black on the blossom end(it's still green and growing), should I just pluck it?

Don't mind me posting here, I'm having similar issues. ;)

Okay, I don't have any cracking yet, but, Noteybook, I believe that that black spot may be Blossom End Rot (sometimes referred to as BER). You can google for more information, but, IIRC, it's physiological and common with many first fruits.

I seemed to have solved my fertilizer quandary though! I had thought ALL fertilizers required mixing in water and then watering (I think people call this "fertigating," but I went to Lowe's and picked up Vegetable Tone and followed the instructions, save the watering. As it is going to rain more in a few hours, I figured I'd sprinkle along the drip lines now, and if it's still dry and visible in the morning, touch up water a bit then.

The threat of hail is half of why I moved them under the raised deck! Bummed that I lost some blossoms cuz of the rain. :/

Although I am not a container gardener, but I think that loss of nutrients is an issue here, especially when associated with excessive watering(manual or rain). I think it has to do with SOIL LESS medium. The so-called DIRT(native soil) is better in trapping and holding the nutrients. Plus, garden beds do not drain too fast and because of that soil act like kind of a filter to hold back the nutrients, where as with the soil less medium it leaches out easily.