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 in the day and northeastward 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: Comparison of photographs from Friday's gas flight with those taken a few days earlier shows that the west and east margins of the new lava dome are crumbling and that the smooth whaleback form is disintegrating. This process also occurred in December, after which the dome renewed the whaleback form after several weeks of extrusion. These periods of disintegration are accompanied by numerous rockfalls, which generate small ash clouds that drift out of the crater.