Warmer weather means more moisture in the air, which means more rain and more snow. Yet, a cold spell in the West has prevented the snow from melting, and now we have a problem.

Thanks to a blizzard-filled winter and an unusually cold and wet spring, more than 90 measuring sites from Montana to New Mexico and California to Colorado have record snowpack totals on the ground for late May, according to a federal report released last week.

Those giant and spectacularly beautiful snowpacks will now melt under the hotter, sunnier skies of June — mildly if weather conditions are just right, wildly and perhaps catastrophically if they are not.

Fear of a sudden thaw, releasing millions of gallons of water through river channels and narrow canyons, has disaster experts on edge.

Of course, the good news is that there is plenty of water for drinking and irrigation.

Hydrologists, meanwhile, are cheering what they say will be a huge increase in water reservoir storage for tens of millions of people across the West. Lake Mead and Lake Powell, two huge dammed reservoirs on the Colorado River battered in recent years by drought, are projected to get 1.5 trillion gallons of new water between them from the mammoth melt.

The bad news is that many communities have been built up in recent decades that are vulnerable to massive, sudden flooding.

Floods kill more Americans than lightning, tornados or hurricanes in an average year, according to federal figures. And flash floods, usually associated with summer downpours, like the one that killed more than 140 people in Big Thompson Canyon in Colorado in 1976, can come as if from nowhere.

“It just takes one really sunny hot spell to get things running,” said Arthur Hinojosa, the chief of the Hydrology and Flood Operations Office with the California Department of Water Resources. “And that’s where our concern lies.”

But try explaining to a Republican that melting snow at the North Pole causes record snowpack in the Rocky Mountains. I guarantee, it won’t compute.