The official search for bodies or any survivors of the May 18 eruption of Mount St. Helens ended in frustration today as rain, snow and thick gray clouds cut short the final mission.

"That's it. It's all over," said Army Maj. Ralph Paduano, after four helicopters flew down from the scarred hills around the volcano and landed at Salkum, a staging base for ground searches since the day after the eruption.

The choppers had been used to ferry ground searchers and tracking dogs into remote, ash-blanketed areas north and northwest of the volcano. Searchers spent only 30 minutes on the ground today before being retrieved because of the bad weather.

The ending came on a somber note. Rescuers, caked in mud to their hips, stood in a circle near the olive-drab helicopters discussing the outside chance of another search. It was pointless, they agreed.

The death toll from the eruption, which scientists said rivaled a hydrogen bomb blast, stood at 22. The missing numbered 53.

Many of the missing are entombed under tons of mud, logs and ash and probably will never be found, authorities said.

About 125 persons were rescued within two days of the blast. After that, only bodies were brought back by a constant shuttle of helicopters and ground searchers.

Today's announcement calling off the search came as the mountain had its first quiet Sunday in three weeks, with aerial observers reporting little ash in the volcano's steam emissions.

"It's been in a stable condition for the past two or three days -- I hope it stays that way," said Paul Lodato, a spokesman for the Federal Emergency Management Agency at the volcano watch center here.

Washington Gov. Dixy Lee Ray said she will ask President Carter for at least $2.5 billion in federal aid to finance the monumental cleanup in southwest Washington, ravaged by volcanic mudflows and flooding, and eastern Washington, which was blanketed in ash.

Geologists, meanwhile, said that contrary to initial indications, a volcanic dome may not yet be forming in the crater, though such a dome is still expected.

"No topographic feature has yet emerged on the crater floor, so it appears that lava has not yet actually erupted to the surface as flows or a volcanic dome," according to a U.S. Geological Survey statement today.

"Nobody's really seen back in there yet visually, but there's well-documented glowing in there, that we're sure of," geologist Tim Hait said today. He told reporters Saturday there were indications a dome had begun to form.

"The incandescence probably reflects the presence of magma very near the surface, releasing hot gases which heat the surface rocks in crater-like vents to temperatures high enough to produce the glow," the statement said.

Hait said a volcanic dome was still expected at Mount St. Helens, and further observations may change scientists' view of what is happening in the steam-shrouded crater.

Steam boiled to heights of 15,000 feet today, as airplanes flying near the volcano reported the rotten-egg smell of hydrogen sulfide and sulfur dioxide. The amount of sulfur dioxide is gradually decreasing, the survey said, but remains 10 times greater than its level before the May 1 explosion.

The statement said most earthquakes in the area were occurring six to 10 miles north of the volcano near Mount Margaret, but these "probably are related more to crustal stesses typical of the region than to the activity at Mount St. Helens."

Meanwhile, measurements of radioactive radon gas in ash near the mountain and in the water of Spirit Lake showed radioactive levels "less than most geothermal areas have naturally," said geologist Mary Hill.

Seismic activity at the volcano continued to be minimal.