Taking it down/disconnecting your radio is the easy solution.
If you want to keep it up during storms, realize that it's difficult for hobby level users to install enough protection to guarantee protection/safety.
As jeepsandradios said above, a ground rod at the base of the antenna is a good start. You also need to ground -all- your equipment to bonded ground rods. One at the mast, bonded back to one for your home.
Based on the soil conductivity, you may need more than one ground rod. Usually you are looking for 5Ω or lower resistance.
Coax should be grounded at the top of the tower, bottom of the tower and where it enters the home.
A lightning protector, like a Polyphaser (brand name) is also required. There are many to choose from, so getting the right one for your frequencies/power level is important.
National Electric Code is the document you should be using to do it to code. Code makes you legal, but you may need to take additional steps.
Here's a good diagram that shows some of the specifics:
If you really want to go nuts, do a search on Motorola R56 standard. It's sort of the Holy Grail of grounding info. Way beyond what you need for hobby use, but still has some great info in it.
