AVO reported that diffuse ash plume from Cleveland was observed on satellite imagery drifting 12 km SE at an altitude below 1.5 km (5,000 ft) a.s.l. during a break in cloud cover on 8 February. Later that day AVO received pilot reports of an ash plume that rose to an altitude of 6.1 km (20,000 ft) a.s.l. and observed the plume on satellite imagery drifting NW. Due to the increased activity, the Volcanic Alert Level was raised to Watch and the Aviation Color Code was raised to Orange. No precursory or current seismic information is available because Cleveland does not have a real-time seismic network. During 10-11 February, a thermal anomaly was possibly visible on satellite imagery. The Volcanic Alert Level was lowered back to Advisory and the Aviation Color Code was lowered to Yellow on 12 February.
Source: Alaska Volcano Observatory (AVO) – “Reports provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”