Excel 2007 :: Conditional Formatting And Adding Text To Cell Based On Multiple Cells

I'm using Excel 2007. I would prefer to stay away from the scripting side of the house if possible. This is basically a 3 day forcast weather chart. The top is the actual weather data, the bottom portion is a color coded reflection of how the weather affects various things.

This product is created in excel, but will be embedded into a powerpoint. It will be updated daily. Here is what I would like. I want the color chart at the bottom to update automatically based on the data I enter above. I have a grasp that I can update the color through conditional formatting, although im not exactly sure what that will look like with all of those cells.

I also figured out that I can insert the letters in those lower cells with something similar to " =IF(C6>90, "T", "") " which would put in a 'T' for Temperature when the temperature got above a certain degree.

I run into a problem when I have multiple factors affecting a single cell. For instance on the example in day 2 of my image. Personnel are affected by Temperate AND UV Index. How would I set up that cell to pull that information from both of those cells and display it accordingly? I would prefer the letters to stay separated by the comma, but I could live without that. The default cell color will be green, with the potential to be yellow or red. I left a few examples of possible situations on day 2 and 3.