I'm really not suggesting anything about creation in my previous thoughts though, not that God created weather, rain, or seasons at the flood, but that the same natural laws put in place at the creation now produced different weather and related phenomena because of the changes that occured during the flood events. Presumably summer and winter, in terms of the length of the day/distance from the sun equation would have existed before the flood as it does afterward, but the effect would not have been as pronounced previously if there were a greenhouse of water vapor equalizing temperatures and preventing the extremes we now take for granted. I would suggest there is no change in natural law, nor any new creation in this scenario, no new chemicals or whatever, but a change in the environment on planet earth brought about by the movement of great quantities of water from high atmosphere to sea beds (and the Psalm referenced before seems to suggest massive earth movements -- plate tectonics -- in the descent of the waters into the seas after the flood).
Just possibilities that make sense to me. The certainty of creation, and of the flood, I am confident of, and am confident that there were changes of great magnitude, whether these thoughts address them accurately or not.