VANCOUVER, Wash. -- Wispy steam rose from Mount St. Helens on Wednesday morning, a day after a steam burst sent a plume of volcanic ash 36,000 feet into the air.

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IMAGES FROM THE MOUNTAIN Slideshow: Images From 3-8-05 Ash Plume Slideshow: Infrared Shots Of Activity At Mount St. Helens Slideshow: Dome In Mount St. Helens Crumbling Slideshow: Glowing Lava Oozes From Crater Slideshow: Large Plume Drifting North-Northeast Slideshow: Steam Eruption On 10-4 Slideshow: User Submitted Mount St. Helens Images Slideshow: Steam Vent Forms After Eruption Images: Mount St. Helens Gets Steamed Slideshow: Steam Shoots From Crater Webcam: Mount St. Helens VolcanoCam

Tuesday's half-hour outpouring began with practically no warning about 5:25 p.m.

MOUNT ST. HELENS Video: Time-Lapse Of Dome’s Growth Video: Time-Lapse Of Fin Growth Video: Thermal Imaging Of Rock Avalanche Slideshow: Hulking Rock Slab Grows In Volcano's Crater Slideshow: Images From 3-8-05 Ash Plume Slideshow: Infrared Shots Of Activity At Mount St. Helens Slideshow: Dome In Mount St. Helens Crumbling Slideshow: Glowing Lava Oozes From Crater Slideshow: Large Plume Drifting North-Northeast Slideshow: Steam Eruption On 10-4 Slideshow: User Submitted Mount St. Helens Images Slideshow: Steam Vent Forms After Eruption Images: Mount St. Helens Gets Steamed Slideshow: Steam Shoots From Crater Webcam: Mount St. Helens VolcanoCam Complete Coverage Of Mount St. Helens

A fine dusting of ash was reported as far as away as southern Grant County -- about 125 miles to the east.

An ashfall advisory for much of Eastern Washington was canceled at midnight.

It was the most powerful blast from Mount St. Helens since the latest round of volcanic activity began last fall, scientists said.

Scientists are hoping to get a look into the crater today.

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Video: Spectacular Eruption Draws Visitors

Roger Cloutier, a senior weather service forecaster, said very fine ash was reported in much of Yakima and Kittitas counties, including Yakima, Ellensburg and Toppenish.

"It's a very light dusting," Cloutier said. "You probably could only see it on cars."

Slideshow: Footage From Tuesday's Ash Plume

Aviation officials said commercial flights at Seattle-Tacoma and Portland, Ore., international airports were not affected.

Scientists said the explosion did not appear to indicate a higher risk of a more dangerous blast, noting that high levels of the kind of gases that often signal an eruption had not been detected in recent flights over the crater.

The latest blast may have been triggered by partial collapse of a lava dome which began growing in the crater beside an older dome in October.

"Until we get a better view in the crater, we won't know," said Bill Steele, coordinator of the Pacific Northwest Seismograph Network at the university in Seattle.

The newer dome had been crumbling slightly in the past week, releasing small puffs of ash and steam, scientists said.

St. Helens, about 50 miles north-northeast of Vancouver, has been spewing ash and steam since last fall.

Starting Sept. 23, swarms of earthquakes peaked above magnitude 3 as magma broke through solid rock as it rose through the mountain, reaching the surface on Oct. 11. Since then the emerging magma has resumed dome-building after a 19-year hiatus.