NOAA operates two Volcanic Ash Advisory Centers (VAAC) -- one in Anchorage, Alaska and the other in Camp Springs, Md. The centers issue advisory statements, including graphics and text messages about the location and size of the ash clouds, which are distributed through several global networks and posted online in real-time.

NOAA's National Centers for Environmental Prediction, also in Camp Springs, runs a Volcanic Ash Forecast Transport and Dispersion model that projects the trajectory and location of the ash cloud at different altitudes on certain time scales.

According to the latest VAAC advisory, "Increased seismic activity at the volcano suggests that an explosive eruption with little -- or no -- warning is possible." Mount St. Helens last erupted in 1980, which killed 57 people and left a thick coating of ash hundreds of miles away from the explosion.

"Volcanic ash plumes pose a costly and potentially deadly risk to planes and their passengers, should they fly through them," said Greg W. Withee, assistant administer for NOAA's Satellites and Information.

Retired Air Force Brig. Gen. David L. Johnson, director of NOAA's National Weather Service, said, "It's critical that pilots know in advance where the ash clouds are headed to avoid these risks, and keep passengers safe." He added that NOAA's Aviation Weather Center in Kansas City, Mo., part of the NWS, is critical to relaying VAAC statements to pilots.

NOAA sends the advisories and dispersion model forecasts to the Federal Aviation Administration, the U.S. Geological Survey, NWS forecast offices, climate analysts and scientists throughout the world.

NOAA scientists and researchers use geostationary and polar-orbiting satellite imagery to track volcanic ash eruptions and ash clouds. In addition to these satellites, NOAA operates moored and free floating data buoys in the world's oceans, research ships and aircraft, and land-based environmental stations -- all providing data that is used to track near term events like the possible eruption of Mount St. Helens or to help combat wildfires, or for the long-term observations of the planet and its natural phases that are used for ecosystem and climate research.

"NOAA researchers keep a constant check on the pulse of the Earth," said retired Navy Vice Admiral Conrad C. Lautenbacher Jr., under secretary of commerce for oceans and atmosphere and NOAA administrator, "so we can protect our citizens from dangerous natural occurrences like volcanic eruptions or hurricanes or tsunamis and to improve the scientific information needed for sound policy decisions in the future."

NOAA's Satellites and Information is the nation's primary source of space-based oceanographic, meteorological, and climate data. It operates the nation's environmental satellites, which are used for ocean and weather observation and forecasting, climate monitoring, and other environmental applications. Some of the oceanographic applications include observation for sea-surface temperature for hurricane and weather forecasting and sea-surface heights for El Nino prediction.

NOAA is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and providing environmental stewardship of the nation's coastal and marine resources.

Relevant Web Sites:

• NOAA http://www.noaa.gov
• NOAA Satellites and Information Service http://www.nesdis.noaa.gov
• NOAA Volcanic Ash Advisory Centers http://www.ssd.noaa.gov/VAAC/messages.html
• NOAA Real-time Mt. St. Helens Satellite Imagery http://www.ssd.noaa.gov/VAAC/hele-img.html
• NOAA Volcanoes Page http://www.noaa.gov/volcanoes.html

IMAGE CAPTIONS:

[Image 1: http://www.noaanews.noaa.gov/stories2004/images/mountsthelens-0518-1980b.jpg (75KB)] NOAA satellite image of the eruption of Mount St. Helens taken at 12:15 p.m. EDT on May 18, 1980. The ring structure is a cloud of volcanic ash propagating outward from the erupting mountain. The image was obtained 36 minutes after eruption. Credit: NOAA.

[Image 2: http://www.noaanews.noaa.gov/stories2004/images/mountsthelens100404-1800zb.jpg (111KB)] NOAA satellite image of Mount St. Helens steam and ash plume taken at 2 p.m. EDT on Oct. 4, 2004, about an hour after being released by the volcano. Credit: NOAA.

[Image 3: http://www.noaanews.noaa.gov/stories2004/images/mountsthelens100504-1700z2.jpg (120KB)] NOAA satellite image of Mount St. Helens steam and ash plume taken at 1 p.m. EDT on Oct. 5, 2004, about an hour after being released by the volcano. Credit: NOAA.