You load up the passengers and head out. By the time you are in the air it is almost 4 p.m. and starting to get a little dark. The overcast cloud is blocking out the sun's last rays, and a lower level of cloud is developing. There are no weather reports coming from the airport that you are heading for, but your alternate is a major northern town that is 90 mi. from your destination. You are halfway to your destination, when ATC calls to let you know that a special weather observation was taken at 4:30 p.m., and that the weather is now 1 mi. visibility in blowing snow, with a ceiling of 800 ft at your alternate. You have no way of knowing what the weather is at your destination, but the cold front has obviously arrived. You are now flying between two layers of clouds, and snow is beginning to fall. What do you do now?
Turn back now. You are not ready for an approach down to minimums at night, with poor weather at the alternate. If you return now, you will beat the storm back to the main base.
You have come this far, you may as well attempt the approach. If you can't get visual, you can at least say that you tried. The instrument landing system (ILS) back at the home base is a piece of cake, so you will be able to get back regardless of the conditions.