cbs' jonathan vigliotti is there. >> reporter: as lava from mauna loa continues to yield spectacular images, the spewing out has slowed considerably. >> at this point we're only dealing with one active fissure, which is fissure 3. >> reporter: the only current threat is the main highway that crosses hawaii island. the flows are now less than three miles away, clearly visible, but they're oozing less than 50 yards per hour, meaning it takes about two hours just to move the length of a football field. geologists say it could take a week, if at all, before the lava reaches the highway. there is also luck. >> there is no imminent threat to residents on the west side or south side of the island at this time. >> reporter: if the eruption took a different path, the city of hilo could have been in the bu bull's-eye. native hawaiians are paying their respects. the eruption has at times sent lava hundreds of feet up into the air. nobody knows when it will stop at this point and what damage, if any, it could cause. five days into the eruption of the world's largest active volcano, the lava, muc

jonathan vigliotti, thank you so much. >>> british royals prince william and indicate middle son arrived in boston today on their first visit to the u.s. in eight years. cbs is there with more on this historic visit. >> reporter: the royals are here, and fans can't contain their excitement. prince william and princess kate arrived in boston this afternoon, the start of a three-day royal visit in the u.s., the first in eight years. among the first stops, boston city hall. >> katherine and i are absolutely delighted to be with you today for our first engagement in the great city of boston. >> reporter: ahead of the visit, prince william announced their attendance at the earthshot prize award ceremony honoring environmentalists, along with a flurry of other stops, including harvard university and the jfk presidential library. >> a super bowl moment for william is how it's been described. it's definitely a setup for him in terms of statesmanship. >> reporter: the royal couple's victim comes after prince william's god mother, lady susan hussey repeatedly asked a black woman what part of afric

cbs' jonathan vigliotti is there. >> reporter: as mauna loa erupts, it's nature's fury and nature's beautylive lava shooting out of a fissure is incredible. >> i've waited my-- my whole life to see this. >> reporter: for 38 years, the world's largest active volcano sat silent. that changed instantly on sunday night, drawing locals and tourists to view a molten masterpiece. the eruption has at times sent lava hundreds of feet up into the air. nobody knows at this point when it will stop, and what damage, if any, it could cause. is this a safe eruption right now? are other communities threatened at this point? >> not according to civil defense. my hopes are that this stays as a beautiful, awesome sight, and doesn't affect people. >> reporter: mauna loa's previous eruptions have come close to wiping out communities. while people are not currently in danger, the slow-moving but persistent lava flow could threaten local roads. >> there's a very high probability that this lava flow, if it continues, will definitely reach the road. >> reporter: there's also an air-quality concern. vog, a mixture

. >> jonathan vigliotti, cbs news. >> it is still unclear how long the lava will continue to flow.entists say it could be days or even a few weeks. >>> back to our weather, today's a storm is not the most welcome sight when you run an outdoor business. rachel wulff visited a christmas tree lot in solano county, to see if the rain dampened the holiday spirit. >> anything that is color coded and tagged, that is how we price. >> reporter: in west sacrament, chad erickson waking up and sizing up his christmas tree lot. >> we don't mind the rain, it is the wind that turns us off. >> reporter: last year, he had no choice but to leave the tree down. >> last year we had a huge tornado come through >> reporter: down the road, they were riding the reindeer. tony and his team taking the time to prep. >> we are getting ready to unload 400+ trees from the home depot. the group of guys that i have out here and everything, they are all happy and joyful, that, you know, they are outside instead of inside. >> i actually enjoy it. >> reporter: despite the weather, work continues. >> a lot of work, i

jonathan vigliotti is there. >> reporter: the pace of this lava is slowing down quite a bit as it reachesrain. geologists, though, say they have detected what they're calling a large number of tremors around the eruption site, which means this lava will continue to flow. mauna loa continues her fury. two active vents are shooting fountains of lava into the air and feeding glowing rivers of molten rock down the mountainside. >> i've waited my whole life to see this. >> reporter: the rare event caused thousands of spectators to jam-pack the dki highway, which became an impromptu viewing point. >> just new -- new birth, new beginnings. >> reporter: but it's also creating a worrisome scenario for officias. >> thousands of residents and visitors that are flocking to the dki and the eruption site to view this current mauna loa eruption is creating a safety hazard. >> reporter: although the flow is slow-moving, it's still pers persistent, and emergency managers are ramping up their plans as it threatens to cross over this same highway. >> it's a very high probability that this lava flow, if it c