IG reported that although visual observations were limited due to cloud cover, ash and steam-and-ash plumes from Tungurahua were spotted and rose to altitudes of 6-9 km (19,700-29,500 ft) a.s.l. during 12-19 February. Ash plumes drifted mainly NW, W, and NE, and ashfall was reported in areas downwind. Roaring noises were occasionally heard. During 12-13 and 16 February, incandescence at the summit was observed. Noises resembling blocks rolling down the flanks were heard on 14 and 17 February. On 18 February, a lahar descended the Achupashal drainage to the NW.
Sources: Instituto Geofísico-Escuela Politécnica Nacional – “Reports provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”