Southall, in his day, was regarded the best in the world.
"Naturally I take a real interest in Tim Howard and always look to see how he is doing," Southall told evertonfc.com.
"I think he has had another great season, he is very consistent and he has done remarkably well since he came here. He is the best keeper we have had for a long, long time and I think there is still room for improvement which bodes well for the future.
"His distribution could improve slightly but generally he has everything you need. He is a great shot stopper, he is good on crosses and he is a good communicator.
"His kicking is maybe the one thing but then again the team plays with one up front most of time so you don't have a great deal to aim at.
"Hopefully he can keep pushing on, stay fit, and keep doing the fantastic job he is doing for Everton for many, many years."