Now, the Mayers are not long in California, after early years in Boston, where the snow comes in trucks. And before that, Mr Mayer and his wife, they came from Canada, and before that, Minsk. We are talking Russia, where the snow is as heavy as history itself.
Well, the two Mayer daughters - Edie and Irene - are grumbling just a little. "After all," they say, "how's it going to be Christmas without the snow to look at?"
Not for the first time, Mr Mayer realises his girls have got heads on them. For this is a question that goes to the heart of all the sentimental claims of Los Angeles and the picture business. I should add that Mr Mayer - who has always been Jewish - long ago made the adjustment with Christmas. He loves it as an occasion, a message, a tableau, because it is so American, so into motherhood and the family, and such a box-office splurge. Mr Mayer has been known to be downright caustic about any Jews in the business who don't have a soft spot for Christmas. He celebrates the season, with a vengeance.
But he worries over the snow. Then, the "Click" goes off in his head. "What I could do," he tells his daughter, "is get the crew up from the studio and spread us a nice couple of feet all over the property" - theirs is one of the great beach houses in Santa Monica - "With maybe some snowmen, and a sled or two?" he adds.
"It won't melt?" asks Edie.
"No way," says Mr Mayer. "It's just gypsum and corn flakes. It'll stay there. Then, around New Year, we vacuum it out."
"But will it feel cold?" wonders Irene - she was always the suspicious one.
"Darling," says LB, "who needs cold?"
There's the nub of the matter. Snow can be a delicate crystalline marvel of nature; or it can be a property, an atmosphere, like lawn or woodland, brought in by the cubic yard. Snow is like a precipitation of the needy soul itself, or it is the cereal of sentimentality.
Thus it was, in June and July of 1946, at the RKO ranch at Encino, they made the snowscapes for It's a Wonderful Life. Encino is 10 miles north of Santa Monica, in the mountains, just beneath Mulholland Drive. RKO had acreage there for major exterior scenes, and that's where they built "Bedford Falls", the all-American town where history unfolds.
The snow was needed for the critical night of the soul where George Bailey comes so close to suicide at the thought of failure in the family bank. But he is accosted by an angel, Clarence, who dissuades him from that drastic action by showing him what would have become of Bedford Falls had George Bailey never been born. George sees the light and the snow fall and runs home, happy again, calling out "Merry Christmas" to all and sundry. The bank survives. The family endures. Life is still wonderful. And Christmas is the shawl of snow drawn up as a comforter - and a white lie.
It's a Wonderful Life is a classic, of course, which means it's a cliche and a chestnut that can surprise you any year you return to it - because it still works, and sustains a notion of American modesty and decency not easily found in the nation itself. OK, but more than that It's a Wonderful Life brought a revolution in movie snow.
For decades, "snow" on screen had been that odd amalgam of shaved gypsum and white-coated corn flakes. Now a change occurred. Maybe it was because director Frank Capra's vision called for the whole of Bedford Falls beneath the snow. Maybe it was also that Capra - educated originally as an engineer - knew enough to take advantage of technologies developed during the Second World War. The studio's special effects man, Russell Sherman, used foamite - the material from fire extinguishers - mixed with sugar and water. He applied it by high-pressure hoses and used 50 tons of the stuff. This was an early version of the artificial snow that is now resorted to by ski slopes when nature is slow to deliver winter's regular show.
In the bright summer light, with the temperature at 90F (32C), a winter of the spirit was laid down at Encino. I dare say the labourers were sweating to make the snow look right - with car tracks, footprints, and those small drifts blown against trees and walls. And it works on film - always has - so you feel as happy as George that he has come through the night in time for Christmas.
My other favourite movie Christmas was actually made for Mr Mayer - Meet Me in St Louis. It shows a year in the life of the Smith family, 1903 to 1904, as they get ready for the Exposition in their city of St Louis, and as they prepare to move to New York City, because of the father's promotion.
The film celebrates their ordinary lives - making ketchup, having their first romances, musical entertainments, braving Halloween, and so on, until they come to Christmas. The anxiety is never quite addressed, but the children don't want to leave St Louis. Late on Christmas Eve, older sister Esther (Judy Garland) finds kid sister Tootie (Margaret O'Brien) gazing out of the window at a garden filled with snow and snowmen. That's when Garland gives her wistful rendering of the uneasy song, "Have Yourself a Merry Little Christmas" - a song by Hugh Martin and Ralph Blanc.
Among other things, the song has the lyric, "Some day soon we all will be together", the mystery of which never fades. I suppose the song was meant for 1944 families separated at holiday time, but the family of this story is all together. So with Judy's eyes widening - she was never lovelier than in 1944 - and her rich vibrato rising and falling on the hope, it has to mean more - so that "some day soon" reaches beyond St Louis or New York, beyond the fretting of life, until the snow might come from Joyce's great story, The Dead: "His soul swooned slowly as he heard the snow falling faintly through the universe and faintly failing, like the descent of their last end, upon all the living and the dead."
Tootie is so moved by the song she rushes down to the garden and smashes the snowmen - so often, Christmas turns out to be a passage of turmoil, frustration and even grief for kids. And Margaret O'Brien was as good a child actress as we have ever had. The family gathers and the move to New York is cancelled. Just as in It's a Wonderful Life, staying home and steady are endorsed: there is no place like home. Meanwhile, the real souls of America cling to their state of blizzard, shift transfer and drift.
The snow in St Louis must be the old-fashioned kind, looking a little blue and amber in the Technicolor night. It's not real snow, which can be so hard to photograph, yet is ineffably mysterious - as witness everything from Herbert Ponting's landscapes brought back from Captain Scott's fatal expedition to the South Pole, to the extraordinary scenes in Smilla's Sense of Snow, one of those films that came close to greatness and then trailed away.
I'm a sucker for snow scenes. I think of the ending of Truffaut's Tirez sur le Pianiste, the manhunt scenes in Nicholas Ray's On Dangerous Ground, Track of the Cat, the William Wellman movie in which Robert Mitchum begins to feel the closeness of a cougar in the snowy wilderness. And Citizen Kane and Bambi.
I know, they sound like the extremes of early-1940s cinema. Yet I wonder. In Citizen Kane, the hero - and the mind telling the story - are haunted by the image of a small house in a snowball, and by its reference to a Colorado childhood so rudely ended when the boy was sent away to grow up as a rich young man. He has never understood why he had to lose his mother. That is the old-fashioned snow, for sure, with bits of it, like sequins, already attached to the shawl Agnes Moorehead will put on as she goes out into the open. And there is falling snow - a shifting, sinking brightness - on the page of the diary that records the incident from Kane's childhood.
If this page were a screen, I could cut to a very similar image, and the same inward falling, in a scene from Bambi - made the very next year - the scene where, after his mother's death, Bambi begins to develop a relationship with his father. There is something profound in the moment, about loss and growing up, that is in the animated snow - like tears, like ageing, like fragments of appearance, like the patter of time - such that I know the makers of Bambi had seen and felt Kane.
"That's so much supposing, I smell a snow job," Mr Mayer might have said. OK, Louis, but snow is a world and a genre unto itself, and snow is like light, wind and rain - it is a helpless bearer of meaning or continuity.