Jon
The thing I like most about sailing is that it is a life long learning process. The more you do it the more competent you become and the less you will be surprised by things like the gust you discribed above.
Reading the wind gusts is most easily accomplished by watching the surface of the water. So make a habit of studying the water surface when you are sailing. Clouds are another indicator of coming wind gusts. The taller and darker the clouds the more likely you will have significantly increased wind gusts under those clouds.
Another thing to do especially if you are not an experienced sailor is to not over power the boat with the sails you are using. On gusty days start out with a working jib and a reef in the main. If you get out there and feel under powered it is easy to shake a reef out on the water to use the full main. Most boats sail best at an angle of heel of 15 to 20 degrees. If you are consistantly heeling over that you are over powered and need to reef or change sails.
Hope this helps some Jon
JERRY CARPENTER - C147
A man can succeed at almost anything for which he has unlimited enthusiam.