Mauna Loa eruption prompts officials to warn of a worst-case scenario - USA TODAY

HST in Moku‘āweoweo, the summit caldera of Mauna Loa in Hawaii Volcanoes National Park, according to a USGS Hawaiian Volcano Observatory alert.

The eruption had remained confined to the summit caldera early Monday, but USGS Volcanoes and the Hawaii Emergency Management Agency later reported some overflowing on the southwest portion.

EST (7:20 a.m. HST) USGS Volcanoes announced the volcano's eruption had moved to the northeast rift zone, with lava flows heading downslope to the north. .

In a later update, USGS Volcanoes announced that the eruption in the northeast rift zone was still ongoing but no lava was erupting from the southwest rift zone.

The Observatory added that it appears the eruption will remain in the northeast rift zone. .

"The shift of the erupting area into the northeast rift zone takes the hazard into much less steep terrain," Hawaii Emergency Management Agency tweeted following the development.

The USGS encouraged residents who are potentially at risk from Mauna Loa lava flows to review their eruption preparations, noting that past events show lava flows can "change rapidly." The Hawaii County Civil Defense also has a Mauna Loa Lava Inundation Zones map for reference

However, if the eruptive vents migrate outside its walls, lava flows may move rapidly downslope," the USGS Hawaiian Volcano Observatory wrote in its Sunday night alert