The U.S. Senate can be accused of a lot of unsavory things, but being unprepared for heavy snow is no longer one of them.

Since last February, in an underground garage on Capital Hill, two new four-wheel-drive vehicles have been parked, unused but at the ready, just in case Senate chiefs get snowbound.

One, for Majority Leader Robert C. Byrd (D-W.Va.), is a $10,000 Ford Bronco. The other, for Minority Leader Howard H. Baker Jr. (R-Tenn.), is a $10,000 Chevrolet Blazer.

Go back 11 months, when Washington over a two-day period was blitzed with 23 inches of snow. The government was paralyzed.

Among those paralyzed was Byrd, snowbound in his suburban Virginia home. Not even his official limousine could break through the drifts.

The man in charge of seeing that Byrd and Baker get to work in Frank N. (Nordy) Hoffman, the Senate's sergeant-at-arms. So he had, as one car maker says, a better idea.

He rushed right out and plunked down $20,000 for the high-powered snow-beaters. "We have to keep this joint running." he said. "and we couldn't get Byrd or Baker in from their homes. The only way was with vehicles like this."

They have been waiting faithfully in the garage ever since. "It's insurance," Hoffmann said. "It's not a silly idea when you're trying to run the government."

The story of the Bronco and the Blazer emerges from the semiannual spending reports of the secretary of the Senate, two massive volumes that routinely detail -- to nickels and dimes -- how the Senate spends its money.

The clerk of the House issues similar reports every six months. Between them, the volumes offer tantalizing insights into congressional operators, which now cost $1 billion a year.

Here are some gleanings -- from blouses to dignitaries -- from the latest Senate report:

The Foreign Relations Committee likes to entertain bigwigs from overseas, using tax money, naturally, but it keeps things in perspective. The more noted the dignitary, apparently, the more it spends.

The real biggie from the last fiscal year was Prince Phillip, who was feted for $3,798. The least spent on any visitor was the $13.90 in goodies consumed when New Zealand legislator Tony Friedlander dropped by

The Capitol is, after all, the property of every American, so it stands to reason that tax money would be used to pay for a staff of tour guides -- about $300,000 a year.

The guides must be well dressed. The guide service last year brought 12 shirts for $100 from Bloomingdale's and 126 blouses for $2,583 from a Washington apparel shop.

Cynics laughed when newly elected Sen. Edward Zorinsky (D-Neb.) came roaring into Washington in 1977 decrying excessive federal spending and lamenting the costly expansion of congressional staffs.

They said Zorinsky would change, that his staff would expand and he would spend like most other senators.

Well, they were wrong. In his three years here, Zorinsky has returned slightly more than $1 million to the Treasury from his official staff allowance.

The secretary's report shows that Zorinsky spent $177,610 on staff during the last six-month period, making his payroll the Senate's most austere. Second-most austers for that period was Quentin Burdick (D-N.D-), who spent $178,314 over six months.

Interesting, how the example catches on. The other Nebraska senator, J.J. Exon, elected after Zorinsky, was the third-most austere. He spent $185,158 on staff salaries.

For comparative purposes, one can book at California, the largest state, and Montana, the 43rd state in population, when considering the Nebraska figures.

The highest Senate payroll during the period was that of S. I. Hayakawa (R-Calif.), who has complained a good deal publicly about big spending in Washington. In six months to spend $596,455 on staff -- or an annual rate of $1,192,910.

Sen. Max Baucus (D-Mont.) spent $394,982 on staff -- more than twice as much as Zorinsky during the period.

The much ballyhooed information explosion has had an impact on Capitol Hill as much as any place else. The secretary's accounting shows Senate committees spending thousands of dollars on subscriptions to specialized newsletters, presumably to get the inside story on what they themselves are doing.

Most of the specialized publications seem directly related to a committee's activities. Banking gets economic newsletters, Labor and Human Resources gets medical and job safety publications, and so on.

But a puzzler shows up now and then. The Veterans Affairs Committee, for example, spent $10 to buy a copy of The New York Times style manual, a handy document if you happen to write for that newspaper.

The daily newspaper also seems to be an important source of information -- every committee subscribes to or buys one or more dailies, the records indicate. Most are the major national papers.

But the Judiciary subcommittee on administrative practice and procedure subscribes to only one out-of-town daily, the Des Moines Register. The subcommittee chairman happens to be John Culver (D-Iowa).

There are other ways to get information, as the constitutional amendments subcommittee of Birch Bayh (d-Ind.) demonstrated. The subcommittee spent more than $150 a month for newspaper clipping service.

Judging from his payroll, Strom Thurmond (R-S.C.) is: (a) running the Hill's biggest welfare agency, (b) operating a school for government, or (c) not praticing the austerity he loves to preach.

Turns out to be none of the above.

The records show that Thurmond had 139 "interns" and "pages" on his personal staff during the six-month period, a staggering figure when compared to the dozen or fewer on most senatorial staffs.

Thurmond for years has run a special summer intern program, giving young people form South Carolina a chance to spend a few weeks on his payroll and learn a bit about government. Some may even do some work.

A Thurmond aide explained that the program has become so popular that the applications pour in each year, with no advertising needed by the senator. No wonder.

If one were to look only at the last names, the Senate's summer employment rolls would suggest a Who's Who of journalists and politicians.

Much of it is coincidence -- no family connection at all. But some of it isn't. The names belong to the children of famous or semifamous political and media people: Laxalt, Duke, Furlong, Leubsdorf, to pick a few.

"These kids came to me and we put them to work," Hoffman said. "They deserve to be considered like anyone else. If some father called me to ask me about a job, I wouldn't hire this kid."