Undecided if you Should lock your interest rate today.
Here's some thoughts on trying to Predict the Future of Interest Rates

HERE’S THE INSIDE SCOOP ON HOW TO DO IT RIGHT!

Choose a lender, that only does lending, has been doing it for at least 5 years, and does at least 5 transaction per month. A lender that is doing volume in this market is more aware of what the current guidelines are (which are constantly changing) and more likely to get priority for their files in underwriting (that's is ability to cut in line). If you do want to play the guessing game think about these 4 things:

1. What are mortgage interest rates based on?
   
   (The only correct answer is Mortgage Backed Securities or Mortgage Bonds, NOT the 10-year Treasury Note. While the 10-year Treasury Note sometimes trends in the same direction as Mortgage Bonds, it is not unusual to see them move in completely opposite directions.)
   
    
2. What is the next Economic Report or event that could cause interest rate movement?
   
   The Fed publishes an economic calendar of weekly economic reports and events that may cause rates to fluctuate.
   
    
3. When the Fed “change rates”, what does this mean… and what impact does this have on mortgage interest rates?
   
   The Fed makes a move, they are changing a rate called the “Fed Funds Rate”.  This is a very short-term rate that impacts credit cards, credit lines, auto loans and the like.  Mortgage rates most often will actually move in the opposite direction as the Fed's change due to the dynamics within the financial markets.
   
    
4. What is happening in the market today and what do you see in the near future?
   
   If your lender is suggesting you wait to lock till tomorrow, "ask why" and "what is happening in the Mortgage Bonds and interest rates today and what is coming up in the near future that makes you think tomorrow's rate will be better".)

Now given all the above, no one can guarantee what tomorrow's rate will be, and they have 50% change of being right on whether tomorrow's rate is higher or lower than today's. My advice is that when you get into contract, confirm the rate that day, and if you can afford it lock and remove the uncertainty, of letting it float and potentially go higher and make home ownership more costly.