Mt. Fitzherbert

Potential ash hazards: Wind forecasts from the National Oceanic and Atmospheric Administration (NOAA), coupled with eruption models, show that any ash clouds that rise above the crater rim today would drift north-northwestward early and northward later.

Potential ash hazards to aviation: Under current eruptive conditions, any ash clouds produced are unlikely to exceed 15,000 feet in altitude. Ashfall from such events rarely reaches more than 20 miles downwind. If the lava dome continues to grow over the next several months, it will become able to produce larger ash clouds that reach higher altitudes and extend farther downwind.

Recent observations: Another large rockfall at about 3:30pm yesterday generated an ash plume that filled the western part of the crater and rose above the rim. On the basis of the seismic signal generated, it was probably similar in size to the one that occurred early Tuesday morning. Slabs of similar dimension are separating from the dome along widening cracks and will likely be sources of future such events. As the dome continues to grow, these types of events are to be expected. Field crews will measure volcanic gases again when winds are favorable, and in the coming weeks will deploy another instrument package on the new lava dome. A GPS package on the bulging east arm of the glacier continues its rapid (4 feet per day) trek northward.