Another Thunderstorm + Star Trails combo. In this case a bit of twilight leftovers comes through the long exposure and adds some sunset colors with those pretty blues (it looked completely dark when this was taken).
Notes: Very little photoshop was used save for removing the noise and a bit of LAB color correction. A good trick to removing chunky noise I've developed for long exposures is to first create an edge mask on a copied layer, select the inverse of that and then apply the dust and scratches filter. Hopefully the edge mask caught most of the star trails to prevent them from being destroyed by the dust and scratches filter. If not, simply add a mask and paint back the star trails on the mask with a black brush which will remove the dust and scratches filter from wherever you paint. Works about as good as anything I've tried.