The Washington metro area real estate market is having a better spring than the Washington Nationals this year as prices and sales continued to rise and new listings increased by more than 15 percent.

The inventory shortage that has plagued the area for months still exists, but sellers gradually are coming off the fence and into the market.

Prices rose 7.7 percent and sales increased 12.3 percent in April, according to Real Estate Business Intelligence data. Arlington and the District recorded their highest median sales price on record in April, with Arlington at $560,000 and the District at 470,000.

"It looks like [sellers] are starting to come back," said David Howell of McEearney & Associates. "In April, every jurisdiction in the immediate D.C. metro area saw an increase in new listings, compared to last April, and in each case the increase was at least 14 percent.

Howell said that is significant because in most of these areas, he has seen declines in new inventory month-over-year for quite some time. In Northern Virginia, the number of listings increased for the first time in nine months, Montgomery County showed its first increase in six months and the District had its first hike in five months.

The rise in new listings could indicate that sellers are being drawn in into the market by higher price points and faster sale times," said RBI's Corey Hart. The median days-on-market is 11, the lowest since 2005 and the sales-to-list price ratio, at 98.2 percent, is the highest since 2006.

Howell urged caution, however, because inventory remains tight with just an 18-day supply of homes priced under $500,000 on the market in Northern Virginia.

One month of increase certainly doesn't constitute a trend, but it does fit our expectation that rising home prices would start to coax more homeowners into making a move," Howell said.

In the District, homeowners find themselves in a more stable real estate environment than in previous years.

With every passing month, there are more homeowners who were upside down that finally have a little equity," Howell said. "That doesn't mean they're going to move, it just means that they can do so much more easily if the need arises."

Homes are appreciating in most areas, Howell said, but not at the aggressive pace of 2004 and 2005. Real estate markets seek balance, and this one will balance out too - but it still will take more time.