How To Read a Skew-T Chart/sounding

Red Line is Temp.
Green line is Dew Point Tmp.
Blue line is Wet Bulb Temp.

Y axis is your Pressure. 850 corresponds to your 850mb maps. 500 corresponds to 500mb. Etc. Usually the colored lines stop at the ground location. X axis is temperature in Celsius.

So find the 0 on the x axis and that is the freezing mark. Work your way up the diagonal line starting at the 0 mark. On the graph I showed you can see the column doesn't start to hit freezing till 850mb's. Meaning the lower levels from about a mile up in the air down to the ground are too warm to support frozen precip.

Also you can see the colored lines come together at 500mb and stay together. This is indicative of a saturated column. In say a virga storm you may see them together from 500 to 850 then spread apart meaning the whole column isn't saturated thus while it looks like precip on a radar it isn't making it to the ground.

Sleet signature would have warm temps aloft and cold temps from about 850 down. Freezing rain would show warm air aloft and a cold layer right at the surface.

There is also a way to interpret snow growth regions from the skew-t but I'm not very good explaining that as I don't understand that facet of the graph fully.