A characteristically slow lava flow in Hawaii is encroaching on a residential area, and is expected to become a threat to homes "within weeks or months," according to experts tracking eruption trajectories.

That's what the US Geological Survey's Hawaiian Volcano Observatory (HVO) announced Friday, and has since been keeping close tabs on lava flow progression along the flank of Pu'u 'Ō'ō on Kīlauea Volcano's East Rift Zone.

Of Hawai'i's five massive shield volcanoes, Kīlauea is by far the most active, and has been intermittently bleeding liquid stone for centuries upon centuries. Its name appropriately means "spewing" or "much spreading" in the Hawaiian language, and its latest eruption, around the Puʻu ʻŌʻō cone, began in 1983.

This eruption is not the like fast and explosive eruptions of many volcanoes in the northern hemisphere. Instead, lava simply continues to ooze out of cracks in the ground and make their gradual rolling way down KÄ«lauea's slope.

A new lava flow, that began on June 27 is still moving, and while it's not "an immediate threat" to Big Island residents, the HVO does believe it is very likely to become one.

"Most lava flows have advanced to the south, reaching the ocean about 75 percent of the time," the observatory reported.

That's what makes this flow more unusual and an impending threat, as it continues to advance northeastward across flat land.

Jim Kauahikaua of the HVO, who is in charge of monitoring the flow, told Big Island Now that this lava is moving faster than previous northern flows, giving it potential to reach residential districts before it can subside. Trenches may need to be dug, or barriers erected to prevent residential damage.

"Up until about a week or so ago, we were only looking at it every two weeks, but we were getting a few satellite images in between," Kauahikaua said.

With a better idea of the flow's dangerous trajectory, the observatory will start keeping closer tabs and posting frequent updates.