Temperatures are dropping and they'll stay below freezing overnight, not getting above 32° until after 9 AM.  This could stress outdoor water pipes and you should definitely bring in the plants and pets.

I could hardly sleep last night.  Yes, I had forecast a rare early snow in Houston for Friday as early as this past Monday.  Even I was slightly skeptical as I watched each successive computer model run show not only snow, but an odd configuration of it.  The model showed a large burst of moisture south of Houston.  Normally, it's colder north of the city and that's where the most snow usually falls.  But that's exactly what happened.  Look at the winter radar from Friday morning:

It shows a large area of rain south of town indicated by the bright yellow and orange colors.  Above this, cold air was descending, as the rain fell, it dropped the temperatures dramatically, leading to the changeover from rain to snow.  This was mostly confined to places like Sugar Land, Pearland, Alvin and Friendswood.  Just a few hours later, the radar picture shows a lot of blue and white coloring, which means sleet and snow:

Here are the impressive snow totals in the Winter Storm 2009.  I hope you took a lot of pictures of this memorable day in Houston weather history: