Lava advanced another 420 yards toward Pahoa since Tuesday and the flow front widened as it approached more level terrain about 2.5 miles upslope of the intersection of Highway 130 and Pahoa Village Road.

The lava flow could threaten the Pahoa Marketplace and the Paradise Park subdivision, depending on which path it takes as it continues downhill.

Hawaiian Volcano Observatory scientists said the lava flow is about 550 yards from a point where several lines of steepest descent nearly converge below an area of flat terrain.

"Until the flow passes this area of flat topography, the future flow path is uncertain," geologists said in a Wednesday update.

Scientists expect the lava’s rate of descent to slow as it reaches the flat area.

Hawaii County Civil Defense said the lava is not an immediate threat to area communities.

Smoke conditions Wednesday were moderate to heavy in the area of the lava flow and through the Kaohe, Leilani, Nanawale and other lower Puna areas southeast of the flow.

Meanwhile, the state Department of Land and Natural Resources arrested two guides for allegedly illegally taking people on tours to see lava.

The department said Tuesday the guides entered forest reserves that were closed. They also allegedly engaged in illegal commercial activities on state-managed land. The agency says an undercover operation led to Monday’s arrest of a 50-year-old man and a 23-year-old woman.

The two were charged with four misdemeanor offenses including conducting illegal commercial activities within a forest reserve and entering a closed area within a natural area reserve. Department Director William Aila says the agency will prosecute trespassers who place officers and emergency personnel at increased risk. Entering closed lands carries a $5,000 fine.