“Hagafell is thought to be a prime location for an eruption,” the forecaster said.
The likely eruption site is near the town of Grindavik, which was evacuated last Saturday due to a string of earthquakes shaking residents and their homes.
The fishing town has been the most affected area in Iceland, as the magma tunnel snakes beneath the ground leaving huge cracks in roads.
While the eruption is most likely to happen in Hagafell, there is a possibility that it could happen anywhere along the magma tunnel.
Although seismic activity has decreased, magma is still moving 3-4cm each day and ground deformation is continuing according to GPS data and satellite imagery.
The head of the volcanic activity department at the Icelandic Met Office said the situation has not developed much in recent days.
Kristín Jónsdóttir noted that while the magma intrusion is still deepening and widening, it is doing so at a slower rate.
She said that a decrease in seismic activity indicates that magma has reached very high up in the earth’s crust and does not now need much for it to reach the surface.
At a Civil Defence briefing on Saturday, director Víðir Reynisson said there is significant damage to houses and pipes in the area.
He said: “This plus uncertainty about earthquakes means that residents have to prepare to live elsewhere in the coming months.”
Locals have been permitted to briefly enter their homes for five minutes this week to collect their valuables and pets but need prior authorisation.
Mayor of Grindavik Fannar Jónasson said that it will take “days and weeks” to resolve housing issues as a result of the evacuations.
He said 1,200 families from the town need more permanent shelter.
“I think the nation has done very well, considering the response and the aid we have received,” he said. “A lot has happened in this one week. I know that there is a lot of impatience and a call from the residents to go faster, but everyone is doing their best and it will take days and weeks to resolve issues.”
Grindavik, a town of 3,400, sits on the Reykjanes Peninsula, about 50 kilometers (31 miles) southwest of the capital, Reykjavik and not far from Keflavik Airport, Iceland’s main facility for international flights. The nearby Blue Lagoon geothermal resort, one of Iceland’s top tourist attractions, has been shut at least until the end of November because of the volcano danger.
A volcanic system on the Reykjanes Peninsula has erupted three times since 2021, after being dormant for 800 years. Previous eruptions occurred in remote valleys without causing damage.
Scientists say a new eruption would likely produce lava but not an ash cloud.