"Mortgage rates are really tied to something called the bond market and interest rates on bonds," says Dr. Walden, a specialist with the North Carolina Cooperative Extension Service. "Now in the bond market there are both private-sector bonds and government bonds.

"But what you need to do if you want to get a jump on where mortgage rates are going is simply to follow the bond market. Specifically you want to follow the interest rates on a particular kind of bond called a 10-year treasury bond," he says.

"And the rule of thumb here is that movement in the 10-year treasury bond will precede movements in mortgage interest rates by up to a couple of days.

"So, for example, if you see the interest rate on a 10-year treasury bond go up on Monday," he explains, "you could probably expect mortgage interest rates to go up on Wednesday or Thursday. So this is a way to get advance warning on what is going to happen to mortgage interest rates."