What does a cross, similar to rings around the moon mean?
It is probably caused by parts of a halo breaking up. Halos are produced by the refraction of light through ice crystals. A solid deck of high cirrostratus clouds is necessary to obtain a complete halo. If there are breaks, you will see some arcs of the halo. Chances are that when you looked up, there happened to be some breaks at just the right spot for you to see a cross. A halo indicates a possible weather change because high clouds are usually the first to make an appearance from approaching storms.
The cross you saw was probably parts of a halo breaking up (halos are produced by the refraction of sunlight through ice crystals). You need a solid deck of high cirrostratus clouds to get a complete halo. If there are breaks, you will see some arcs of the halo. Chances are that when you looked up, there happened to be some breaks at just the right spot for you to see a cross. In any case, a halo indicates a weather change because high clouds are usually the first to make an appearance from approaching storms.