Updated at 3:30 p.m. to emphasis that the warning upgrade is for the Aviation Warning Code.
Hawaiian Volcano Observatory upgraded its Aviation Warning Code from orange to red on Tuesday afternoon.
A red warning means that major volcanic eruption is imminent, underway, or suspected with hazardous activity both on the ground and in the air.
The color change is based on the fact that activity may become more explosive, increasing the intensity of ash production and producing ballistic projectiles near the vent.
As of early Tuesday morning, eruption of ash from the Overlook vent within Halemaumau crater at Kilauea Volcano’s summit has generally increased in intensity, per HVO.
Ash has been rising nearly continuously from the vent and drifting downwind to the southwest. Ashfall and vog (volcanic air pollution) has been reported in Pahala, about 18 miles downwind.
National Weather Service radar and pilot reports indicate the top of the ash cloud is as high as 10,000 to 12,000 feet above sea level, but this may be expected to vary depending on the vigor of activity and wind conditions.
Ash emission from the Kilauea summit vent will likely be variable with periods of increased and decreased intensity depending on the occurrence of rockfalls into the vent and other changes within the vent.
Photo: A voluminous and ash-laden plume could be seen this morning from the Volcano Golf Course in Volcano, Hawaii. This view is nearly due north of the Halema‘uma‘u plume. USGS photo.