USGS Update 2004-Nov-30 10:50
Wind forecasts from the National Oceanic and Atmospheric Administration (NOAA), coupled with eruption models, show that ash clouds that rise high above the crater rim today would drift east-southeastward early in the day and south-southeastward later.
Recent observations:
A variety of field activities, including thermal-imaging measurements, visual and photographic observations, and collection of ash samples from the volcano's south flank, were conducted yesterday under nearly ideal conditions. The only snag was lingering fog in the Tualatin Valley that prohibited launching of the gas-sensing flight. Several excellent photographs posted on our web site show the new lava dome within the welt, or broad area of uplift, in the southern part of the crater. The dome owes its smooth elongate appearance to ongoing extrusion from a vent at its north end, which lies at the south margin of the lava dome that grew between 1980 and 1986. The lava emerges from the vent with enough strength that it can push earlier-extruded lava southward toward the crater wall. The leading edge of the extrusion has now reached the crater wall, so it will be interesting to see what happens over coming days. Will new lava start to well upward over the vent and piggyback on the south side of the 1980s dome rather than continue to push against the buttress provided by the crater wall? Or will new lava move eastward or westward in a pattern similar to its southward movement? As in previous days, a few larger earthquakes of about magnitude 2.5 occurred amidst the ongoing sequence of smaller (mostly less than M1.5) earthquakes. Such a pattern represents nothing unusual in the expected sequence of events accompanying lava-dome growth.
Mt. Fitzherbert

Aerial views taken late yesterday afternoon