Click this link and print it if you plan on using a tarp.
http://www.bushwalking.org.au/FAQ/tarp/TarpShel.htm
I use a tarp in all weather conditions. Advantages are primarily cost and availability. Tarps may be purchased almost anywhere, most good tents must be ordered through specialty stores. If you damage your tarp during a tour you may replace it easily by purchasing a new one. If you damage your tent, good luck replacing it during the trip. Tarps are so cheap there disposable eliminating storage of a tent between tours. Purchase a new tarp before the tour and dispose of it in a trash can the last day of the tour. Purchase your tarp and practice putting it up before the tour starts. After you determine the size and shape of the tarp shelter you like use a permanent marker to indicate fold lines making setup faster and easier.
