This evening's thread explores how the Mauna Loa eruption is like a jelly donut. Stick with us -- we're not scientists but we know our way around a handy metaphor. #MaunaLoa 🧵 (1/9) When lava runs down a hill, it acts a lot like water. It seeks the steepest path, and its flow is somewhat predictable. But when it hits a plateau, like the Big Island saddle, things change. They slow down. That's where Mauna Loa is now. (2/9)

What's slower than slow? The Mauna Loa lava front, which slowed even more in the past 24 hours, to about 75 feet per hour. It's still about 2.5 miles from the highway Saturday morning, and poses no immediate threat to any populated areas. #MaunaLoa All volcanic activity is being observed in the Saddle area northeast of Mauna Loa, with NO evidence of any threat to communities in the west or south portions of the Big Island.

The @USGSVolcanoes Hawaiian Volcano Observatory reports that an eruption began around 11:30 p.m. HST in Moku‘āweoweo, the summit caldera of Mauna Loa. At this time, the eruption is limited to the summit area and is NOT threatening communities downhill. The Observatory has increased the Volcano Alert Level from “advisory” to “warning,” with aviation alert upgraded to “red.” Some ash and volcanic glass fibers may become airborne and blow downwind.