GMU’s Lisa A. Sturtevant writes an occasional column analyzing housing market trends in the Washington region.

Are would-be home sellers finally getting off the sidelines and finding it’s time to get into the market?

Across the region, there have been months of steady home sales, increasing home prices and depleting inventories. New listings were slow to come on market. However, new listings jumped substantially in April.

Is this surge signs of a fundamental shift in the market or a temporary blip?

There were more than 11,100 new listings in the Washington metropolitan area in April. Compared to March, the number of new listings is up 22 percent. An increase in new listings this large is not a typical March-to-April bump. In fact, last year, the number of new listings in April was lower than the number in March.

The increase in new listings this April is markedly different from the trends over the past year. In the 22-jurisdiction Washington metropolitan area, the number of new listings in April is 16 percent higher than the number of new listings in April 2012. (By contrast, new listings in March were 12 percent lower than March 2012.)

While new listings are up across most of the region, the biggest increases are in some of the outer suburban jurisdictions. For example, there were 328 new listings in Stafford County, up more than 42 percent from last April. In  Fredericksburg, the 51 new listings in April represent a 34 percent increase over April 2012. Closer-in, the biggest gain in new listings was in Montgomery County, where there were 1,798 new listings in April compared to 1,461 new listings in April 2012, an increase of 23 percent.

This is the first time since the beginning of the housing market recovery that there have been year-over-year increases in new listings across most of the region’s jurisdictions.

The number of active listings at the end of April is still very low. Sales activity has been relatively brisk across the region, which has drawn down inventories. However, with the increase in new listings in April — and the modest slowdown in sales in the beginning of 2013 — inventories are rising.

In almost every jurisdiction across the region, the year-over-year percent increase in new listings outpaced the percent increase in sales in April. In other words, new listings came on the market at a faster rate than sales took them off the market. In April, the number of sales regionwide totaled 56 percent of the number of new listings in that month. But new inventory is being drawn down faster in Prince George’s County, Arlington County and the city of Manassas Park, where sales were 65 percent or more of new listings in April.

If the pace of new listings continues into May and June, inventories will increase and price growth should moderate. It will take another month or two of data to see if the rising contributions to the existing inventory will be sustainable.

Sturtevant is deputy director of the Center for Regional Analysis at George Mason  University.