St. Louis Cardinal fans are prepared for a double dose of trepidation Saturday. First, they will look out their windows to check the weather. Second, after arriving at Buschi Stadium, they will search for signs of their heroes' intensity.

Snow, which has kept St. Louis schools closed for three days, also has plagued Cardinal practices. Today, freezing rain and ice joined the assault before the rain turned to snow tonight. The forecast for Saturday anticipates extreme cold - zero temperatures at dawn rising no higher than the upper teens, and a chance of more snow.

There is no question that bad weather would hamper the Cardinals' speed-oriented offense more than it would the visiting Washinton Redskins.

"I like a dry, fast field," said St. Louis coach Don Coryell. "That's to our afvantage with our small backs. Weather conditions affect us more than some teams. We've had poor practice conditions all week. It's too cold. And with the snow the first day see couldn't do more than walk through things. Now it's very wet."

The subject of player ups and downs is also much discussed here, where is team that beat Minnesota and Dallas has been demolished in successive games by Miami and the New York Giants.

Certainly, the player seemed relexed today, as they killed time playing Foosball. Everybody enjoyed a chuckle at a cartoon, submitted by a fan, and that showed Eve plucking an apple and Adam saying, "Do you know what you've done? You've caused foods, famine and George Allen."

"The whole season comes down to this one," said cornerback Roger Wehrili. "If you're not up for this one, you'll never be up. In the Dallas game, we showed intensity that we have to regain. This is a pretty loose team. It's a hard team toread."

Quarterback Jim hart agreed with Wehrili's evaluation of the team's roller-coaster mood.

"We were relaxed and loose before the Minnesota game," Hart said. "And the way guys were clowning I thought maybby we ought to stop it. Then we blew them out.

"Before the Dallas game, the team seemed tight and I thought maybe (offenseive tackle Dan) Dierdorf and I should start clowning to loosen things up. We beat them ,too."

"I've never been able to figure out ahead of time how a team of mine will play," Coryell said."On etime we will have a great week of practice and fall on our face. Another time we will practice poorly and play very well."

Coryell has been sleeping in his office this week, with assistants for roommates. One morning he was seen wandering around in team's Busch Stadium offices in a tee-shirt, carrying a toothbrush and paste. Another time, a sweater found in the public relations office was traced to Coryell. Fifteen minutes after it had been returned, it was found lying on the floor in the hallway.

Tonight, despite the snow, Coryell decided to drive to his suburbab home. It was not, he said, an indication his preparations for the Redskins were complete.

"There's always more to be done," Coryell said. "I just think I want to go home. I want to be with my family one night this week."

Coryell probably has seen enough Redskin movies. The Cardinals have been working daily from 10 a.m. to 4:30 p.m., with films taking up a good portion of the sessions since outdoor practice has been limited. Naturally, a major jsbect of interest to those watching the films is Redskin quarterback Joe Theisman.

"theismann is such a great runner," Coryell said. "He's so dangerous he hurts your ability to tee off on the pass rush. Both Theismann and (Billy) Kilmer are great competitiors. Kilmer beat us last time, but I have great respect for Theismann."

"Kilmer has more experience, but Theismann is more mobile," Wehrili said. "Theismann picks up yardage on his own when you think he's stopped. He's a lot like (Roger) Starbach."

Wehrili thinks the breakdown of the Cardinal defensive secondary after injuries to Lee Nelson and Mike Sensibaugh was overdramatized.

"The other guys were with us all year," Wehrili said."(Jeff) Severson played as long as Sensibaugh. We lost both Perry Smith and Nelson on the other corner and Carl (Allen) was nervous his first game, but he was okay in the second. We knew it would be tough, losing two guys out of the secondary in one game, but we can't blame the last two defeats on that. We haven't played well as a team."

Wehrili, a frequent all-pro, has intercepted five passes his season for a pro career total of 29 and has picked up three fumbles to become the Cardinals' all-time leader with 17. But, as usual, he expects a difficult afternoon with Washington.

"The Redskins seem to have our number," Wehrli said. "They've played well defensively and they've enough to get points on the board, with punt returns if nothing else. (Danny) Buggs has played extremely well, given them excellent speed. He's an extra threat, an added dimension to their offense."

Of course, a major factor in the Redskins' recent successes has been fumbles by Cardinal runing back Terry Metcalf. A letter to the editor of the St. Louis Globe-Democrat today suggested that Metcalf watch Saturday's game, because "he has a tremendous amoungt of ability to fumble theball. If the man makes an apearance, we can kiss victory goodbye."

Perhaps that opinion had something to do with Metcalf's reluctance to be interviewed after today's practice. Instead, he played Foosball with the son of mananging partner Bill Bidwill.

All Cardinal home games were sold out this season for the first time, but a few tickets remain for this contest because the Redskins returned 188 of their 350 tickets. The last few may never be sold, considering the weather and local telecast of the game, and the club expects a record number of no-shows.