This apocalypse is refusing to cooperate.

The national press corps descended on Vancouver Friday, smelling disaster, armed with cameras, braced for Pompeii. Atlantis. The lava that ate Portland. Little planes laden with reporters and television crews already were roaring into the sky, trying hard to avoid the volcanic plumes (and each other).

Everybody was wildly envious of the Oregonian staff photographer who made a gorgeous moonlight picture of Mt. St. Helens, white and brilliant in the night illumination, spewing hot, thick ash into the air.

All over America, editors yelled long distance at their photographers: "Why didn't you get that picture?"

Mt. St. Helens has disappeared, is why. Early Friday the sky went lead-colored with a cloud cover that socked in the whole mountain.

The little planes kept going up, but all they could see were long black plumes shooting up through the gray-enormous plumes, 16,000 feet above sea level in some places, billowing dark and spectacular over the clouds. This morning it started to rain. The planes stayed down. The Forest Service people held another news conference to repeat their conviction that the situation would either worsen, improve or stay about the same.

The situation, obscured as it is by the aggravating but predictable Pacific Northwest spring weather, is this: Mt. St. Helens, at age 2500, a mere baby of a volcano in the Cascade range, is still rumbling and belching its way through the first American "lower 48" eruption in more than 60 years.

A hundred people have been evacuated from homes in a 15-mile radius of Mt. St. Helens' peak -- with the exception of an 83-year-old lodge owner who has firmly announced that he is not going to budge. Three hundred Washington National Guard members have been placed on stand-by alert in case further evacuations are necessary.

Roadblocks have been set up around the mountain to keep out enthralled sightseers, who have been piling into their cars and driving straight toward the eruption in such numbers that the police have been pleading with people to please stay home and watch it on television or something.

But immediate danger, according to geologists and Forest Service spokesmen, is minimal.

The wind is spreading ash (fine-grain erupted material, with a texture like sand) as far as 50 miles to the east of Mt. St. Helens, where it settles lightly over the mountain terrain. The long-term ecological effect is uncertain:

There has been some concern over the three linked reservoirs at the base of Mt. St. Helens. A massive mudslide into the top reservoir might trigger a chain reaction of overflow and flood the inhabited area below the lowest reservoirs. An official from Pacific Power and Light, the utility company that owns the reservoirs, said the water level was being reduced in the top reservoir to allow room for any mud that might slide into the water.

Mt. St. Helens erupted last during the 1840s and '50s, in a series of eruptions that were described by a number of astonished observers. The American missionary Samuel Parker, writing in his journal, described days of eerie quiet and total darkness "except a slight red, lurid in appearance, which was perceptible until near night."

Scientists here cannot explain exactly what brought an end to the mountain's dormant period -- just what it was that made magma, or molten rock, work its way toward the surface to force steam and hot gases through cracks in the rock.

They are not certain, either, about the precise relationship between the volcano's eruption and the strong earthquakes that accompanied it -- whether the earthquakes forced open a crack in the volcano's base, which allowed the pent-up heat to shoot up and out; or whether perhaps the earth was forced open by the intense pressure of magma working its way toward the surface.

As far as they can tell, though, from observation of the ashy plumes and examination of the material being expelled, the volcano so far is spewing only fragments from the much older volcano on which it rests. Hot, dry and reeking with the rotten-egg smell of hydrogen sulfide, the rock and ash is shot up through the core as intensely hot groundwater reaches the surface and flashes into steam.

No magma, the underground source of the furious heat, appears to have broken through. "We are seeing no lava flows," said Bob Christiansen, a U.S. Geological Survey geologist who flew above Mt. St. Helens Friday. "We have no indication whether or not we will see lava."

In the meantime, during an otherwise ordinary sort of week in southern Washington, the eruption has taken on the nature of grand theater.

There are D-Day-sized headlines in the local newspapers. ("St. Helens' Snowy Cap Shattered"). The hotels are doing a brisk business in eager reporters, and the T shirts already proliferate. One local paper ran a picture of two, on smiling models. "I Erupted at Mt. St. Helens," said the first, and on the other: "Mt. St. Helens -- Lava or Leave It."