April showers bring May flowers, and May could bring lower mortgage rates.

At least, that's the consensus among several housing economists, who say the Federal Reserve Board will soon be forced to lower interest rates in order to reignite the sluggish economy."Between now and June or July, I think you'll see rates drop another quarter-point or so," said Dick Peach, an economist with the Mortgage Bankers Association of America.

"The economy isn't growing much, unemployment is up and the inflation rate is low. There's room for the Fed to lower rates, and I think it could happen relatively soon."

The Federal Reserve Board, or "Fed," is the nation's central bank. Because it controls the money supply, it wields large influence over the economy.

When the economy is slow - as it is today - the Fed often lowers interest rates to encourage more borrowing and stimulate business.

"No one can say with certainty what the Fed will do next, but I wouldn't be surprised if we see a quarter-point or half-point drop in rates over the next three to six months," said Leslie Appleton-Young, an economist for the California Association of Realtors.

What does all this mean if you're thinking of buying a house or refinancing an existing mortgage?

It all depends.

If you're shopping for a home in an area where prices aren't rising much, you can afford to take your time if you think that rates will go lower. Your patience could result in a reduced monthly mortgage bill.

Conversely, if home values in the area are starting to pick up, it probably won't pay to wait.

"Don't sit around and wait for interest rates to drop a little if prices in your area are rising fast," said John Tuccillo, chief economist of the National Association of Realtors.

"If prices go up just 1 percent or 2 percent over the next few months, it'll wipe out any saving you'd get by waiting for rates to nudge down-ward."

Of course, when you're shopping for a loan, it's always a good idea to get a "rate lock."

A rate lock is basically a promise by a lender to give you a loan at a specified rate and on certain other terms within a specified period of time.

For example, if a lender offered you a 30-day rate lock on a 10 percent loan with two upfront points, you'd get the loan on those terms even if rates skyrocket over the next few weeks.

But what happens if you get a rate lock and rates go down? A lot depends on exactly how far rates drop and how much you have paid in non-refundable fees for an appraisal, credit report and the like.

If you have already paid several hundred dollars in non-refundable fees and rates edge down just a quarter-point or so, you should probably go ahead and take out the loan even if your lender won't offer you the lower rate.

"It wouldn't make sense to switch lenders and lose several hundred dollars (in upfront fees) just to knock $10 or $15 off your monthly mortgage bill," Tuccillo said.

But in the unlikely scenario that rates drop a point or more and you haven't committed much cash, insist that the lender give you the lower rate or consider taking your business elsewhere.

Over time, the money you save through lower monthly payments will offset the money you lose by backing out of the original deal.