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 in variable directions with time and altitude. Early clouds would drift lazily northward at low elevation, but east-northeastward at higher altitudes. Later, low-level clouds would drift lazily north-northwestward, but more southeastward at higher altitudes.

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: The crater is partly obscured by clouds this morning. A minor ash emission, much smaller than that of Friday afternoon, occurred yesterday morning. On the basis of seismicity, a similar event may have occurred early this morning. Further analysis of recent aerial photos reveals that as of February 1, the whaleback-shaped extrusion is about 1,550 feet long and 500 feet wide. The new dome and uplifted welt of crater floor and deformed glacier ice have grown to a combined volume of about 50 million cubic yards, almost one-half the volume of the old lava dome.