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December 1, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash. During such eruptions, changes in the level of activity can occur over days to months. The eruption could intensify suddenly or with little warning and produce explosions that cause hazardous conditions within several miles of the crater and farther downwind. Small lahars could suddenly descend the Toutle River if triggered by heavy rain or by interaction of hot rocks with snow and ice. These lahars pose a negligible hazard below the Sediment Retention Structure (SRS) but could pose a hazard along the river channel upstream.
- Wind forecasts from the National Oceanic and Atmospheric Administration (NOAA), coupled with eruption models, show that any ash clouds rising above the crater rim today would drift generally eastward in the morning, shifting to the northeast by afternoon.
- Potential ash hazards to aviation: Under current eruptive conditions, small, short-lived explosions may produce ash clouds that exceed 30,000 feet in altitude. Ash from such events can travel 100 miles or more downwind.
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- Recent observations: The active spine of the lava dome continues to inch outward, according to instrumental data. The tiltmeter at NDM, adjacent to the north, shows small inflation-deflation events every few hours, some of them associated with small earthquakes. These tilt events likely signal dome growth pulses. Our last good image from the Sugarbowl cam was November 28; it showed no notable landscape changes. Views from the publically accessible JRO cam rarely capture more than the mouth of the crater, if that, owing to poor weather. The discharge from streams exiting the crater appears normal, judging from acoustic flow monitor real-time data. Stream discharge likely will remain normal during the snowy conditions of Saturday and early Sunday but may change abruptly at middle elevations on Sunday or Monday, inasmuch as a warming rain is forecast for the region.
- *** This line included in daily update but excluded for rest of month on this page.
December 2, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift northeast.
- Recent observations: The active spine of the lava dome continues to extrude, according to our in-crater tiltmeter. This instrument, located adjacent to the new dome’s north flank, shows small inflation-deflation events every few hours, which we interpret as dome growth pulses. The wind from winter storms has increased the noise on seismometers close to or in the crater, saturating them relative to the sparse small earthquakes that have characterized the eruption as of late. No in-crater GPS results are available this morning. Views from all volcano cams in the past 24 hours have been useless for assessing eruptive activity, owing to poor weather. The discharge from streams exiting the crater has increased slightly, as measured by acoustic flow monitors. Stream discharge likely will increase slowly early Sunday. It may change abruptly at middle elevations by Sunday evening or Monday, when a rain-rich warm front is forecast for the region.
December 3, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift northeast.
- Recent observations: The active spine of the lava dome continues to extrude, according to our in-crater tiltmeter. This instrument shows small inflation-deflation events every few hours, which we interpret as dome growth pulses. The wind from winter storms has increased the noise on seismometers close to or in the crater, saturating them relative to the sparse small earthquakes that have characterized the eruption as of late. No in-crater GPS results are available this morning. Views from all volcano cams in the past 24 hours have been useless for assessing eruptive activity, owing to poor weather.
December 4, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift ENE.
- Recent observations: Yesterdays heavy rainfall registered strongly on MSH seismic- and flow-monitoring systems, but no remarkable flows were generated by the rain on the volcano, nor was there significant rain-induced seismicity or steam venting. Some radio telemetry was lost during the storm, but most has come back since then. Seismic and deformation monitoring parameters are within normal ranges typical of the last weeks and months. The mountain is clouded in this morning.
December 5, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift east.
- Recent observations: MSH is clear this morning, above the valley fog in lower elevations. Flow-monitoring systems suggest small lahars flowed out of the crater yesterday after the weather system passed the region. Some of the flow may have made it as far as the SRS. At this time flows have subsided. Volcano seismicity remains at normal background levels; storm-related noise has calmed down.
December 6, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift easterly early in the day, switching to westerly by late afternoon local time .
- Recent observations: More rain at MSH today; the volcano is obscured. Seismic and flow monitoring show no rain-related flows or seismicity yet today. Seismic monitoring parameters are within normal limits typical of the last weeks and months.
December 7, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift south.
- Recent observations: MSH is socked in this morning, but not drowning in rain. No notable rain-related seismicity or lahars have been registered by flow-and seismic-monitoring networks since yesterdays update. Several telemetered monitoring stations are still off-line since the storm earlier this week, and are presumed hors de combat. Current seismicity is normal, typical of the last weeks and months.
December 8, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift southerly.
- Recent observations: Seismicity is normal, typical of the last weeks and months. Rain has abated and flow monitors register no lahars flowing of the crater.
December 9, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift south.
- Recent observations: Seismicity is at normal background levels typical of the last weeks and months. Yesterday field USGS and UW field crews took advantage of the clear weather to make repairs to monitoring equipment in the crater and avoid holiday shopping crowds in town.
December 10, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift southward.
- Recent observations: Mount St. Helens is clear today, with a little steam rising from the new dome. Seismicity and deformation remain at low levels as slow extrusion of the new dome continues.
December 11, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift NNE.
- Recent observations: MSH is clear this morning with the usual small steam plume off the new dome. Seismicity is at normal background levels typical of the last weeks and months. Yesterday field crews finished maintenance on south flank seismic stations, restoring important monitoring data streams lost during last weeks storms.
December 12, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift eastward.
- Recent observations: The mountain is obscured by clouds this morning as a weak front sweeps across our area. Seismicity and deformation remain at low levels as extrusion continues. No significant changes have occurred in the last 24 hours.
December 13, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift southeastward.
- Recent observations: The mountain is again obscured by clouds this morning, and the noise on the seismic stations on the outer flanks indicate stormy conditions. Little has changed in the deformation or seismicity within the last 24 hours, as extrusion of the new dome continues.
December 14, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift southeastward.
- Recent observations: Mount St. Helens remains obscured by clouds and hammered by wind and snow this morning. Our instrumentation indicates continued extrusion, and there have been no significant changes within the last 24 hours.
December 15, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift ENE.
- Recent observations: The mountain is shrouded in low clouds and fog today. Telemetered instruments show no significant changes from the pattern of the last few months indicating that slow steady extrusion of the new lava dome in the crater is continuing.
December 16, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift NE.
- Recent observations: Camera views show Mount St. Helens to be clear this morning under a high overcast. A light steam plume is drifting over the east rim through Shoestring Notch. Telemetered instruments show no significant changes in the behavior of the volcano overnight. The slow growth of the new lava dome is continuing.
December 17, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift eastward.
- Recent observations: Mount St. Helens is completely obscured by clouds this morning, though our instrumentation indicates that lava extrusion continues. There have been no significant changes in the last 24 hours.
December 18, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift northward in the morning and eastward in the afternoon.
- Recent observations: Monitoring instruments on Mount St. Helens have remained operational throughout the recent heavy snow fall. A shallow magnitude 1.9 earthquake occurred in the crater at 05:51 AM this morning. Slow ground deformation, measured with tiltmeters and GPS, indicates that ongoing extrusion of the lava dome continues.
December 19, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift to the northeast.
- Recent observations: Clouds block views into the crater today. The signal from a magnitude 7.2 earthquake (0130 PST) in the Aleutian Islands is evident on the generally quiet St. Helens seismic records. Slow ground deformation, measured with tiltmeters and GPS, indicates that ongoing extrusion of the lava dome continues.
December 20, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift northeastward in the morning and southeastward in the afternoon.
- Recent observations: Monitoring instruments on the volcano remain operational despite recent heavy snowfall. Photographs from a remote surveillance camera taken earlier in the month show what appears to be a new rock spine emerging through the ruble pile. Ongoing ground deformation, occasional small earthquakes, and rock falls are consistent with continued slow growth of the lava dome.
December 21, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift southeastward.
- Recent observations: A short break in the winter weather this morning allowed partial views of a snow clad Mount St. Helens from remote cameras at the Johnston Ridge Observatory. Occasional small earthquakes and rockfalls punctuate otherwise quiet seismic records. Brief episodes of slow ground deformation are seen in tiltmeter records from instruments located near the active vent. These observations are consistent with continued slow growth of the lava dome.
December 22, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift northeastward in the morning and eastward in the afternoon.
- Recent observations: Gusting winds from a strong winter storm has increased the background noise recorded by seismic and tiltmeter monitoring instruments on Mount St. Helens. We note no change in the number or size of earthquakes, rockfalls, or slow ground deformation events. This sporadic activity is consistent with continued slow growth of the lava dome.
December 23, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift northeastward.
- Recent observations: The mouth of the crater is barely visible through clouds that surround Mount St. Helens this morning. No change is observed in seismicity or deformation except for increased background noise from winds associated with an approaching winter storm.
December 24, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift eastward in the morning and southeastward in the afternoon.
- Recent observations: ‘Twas night at St. Helens, and under darkening skies the eruption continues, but no tephra flies. Our instruments twitch, they tilt and they snap probing for when the volcano settles in for a nap. Rockfalls occur, tails sometimes aglow, the dome is still growing, but growing quite slow. As rock pushes ice, local thickness can double and Crater Glacier speeds forth, its arms racing on rubble. The rivers run high, it’s that time of year, but nothing’s unusual, water is mostly clear. We keep diligent watch should the mountain change pace and decide to try on an aggressive face. As winter sets in and piles up snow, if anything changes, we’ll let you know. From the CVO staff, a bit of holiday cheer, have a joyous time and a happy new year.
December 25, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift east this morning, shifting to northeast by afternoon.
- Recent observations: A few tiny earthquakes (less than magnitude 1) occurring each day and a few small tilt events probably related to deformation in the shallow volcanic conduit are the main indicator that lava extrusion continues at an otherwise moribund volcano. Infrequent, well-located larger earthquakes, in the range M1-2, have been recorded once or twice per week during the past month. No data are available from in-crater GPS receivers. Videocam observations in the previous 12 hours show the volcano in the light of the moon, its active spine steaming slightly.
December 26, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift southeast.
- Recent observations: High winds have saturated the seismometers closest to the new dome as a winter storm develops. The result has been a small spike in the real-time seismic amplitude measurements this morning, albeit in the absence of notable volcanic activity. Our in-crater tiltmeter shows only the sparse small tilt events related to deformation in the shallow volcanic conduit, currently the main indicator that dome lava is extruding sluggishly and quietly. Videocam observations have been obscured by the weather during the previous 12 hours.
December 27, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift to the southeast early in the day and to the northeast later in the day.
- Recent observations: Another winter storm is hitting the area. The volcano is obscured from view, but our in-crater tiltmeters show small tilt events related to dome growth. There has been little earthquake activity over the past 24 hours.
December 28, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift eastward to east-southeastward.
- Recent observations: Conditions remain unchanged from those of the past few months. Persistent cloudiness has prevented views of the growing lava dome.
December 29, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift to the east-southeast early in the day and to the east later in the day.
- Recent observations: The snowy base of the volcano to the crater breach is visible in the JRO volcano cam, with the upper flanks obscured by clouds. The recent storm has affected the telemetry of many of our seismic stations, but those operating show very few earthquakes. Small perturbations in deformation from our in-crater tiltmeters indicate that slow extrusion of the lava dome continues.
December 30, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift eastward.
- Recent observations: Heavy snow is interrupting signals from some seismic stations, but other stations in the network, along with tiltmeters, show that there has been no change in eruptive conditions. Clearing weather over the next few days may allow aerial observations and station maintenance.
December 31, 2007:
- Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds rising above the crater rim today would drift southeastward, but later today some low-altitude ash would drift westward to northwestward.
- Recent observations: Today's clearing provides the first views of the crater and growing lava dome in many days. Snow covers much of the dome's flanks and clouds of water vapor obscure the top. Data from monitoring networks show no change in eruptive conditions.
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