SAN FRANCISCO (CBS) — Government scientists predict a 95 percent chance a strong El Niño building in the Pacific will continue through the winter but there’s no guarantee the rain will fall where California needs it most.

The Golden State’s reservoirs are running on empty. They’ve lost six trillion gallons of water during four years of drought.

Now, a wild and wet winter is in the forecast for California thanks to the intense warming of the Pacific Ocean near the equator known as El Niño .

NASA Oceanographer Bill Patzert warns “don’t count your raindrops yet.”

He says El Niño should bring rain to California, but the drought-thirsty Pacific Northwest is forecast to be drier than normal this winter.

Even the heavy rain forecast in Southern California is not a drought buster. The area is engineered with concrete channels designed not to capture water. Instead, water is flushed out to the ocean to protect homes from flooding.

“We made a decision in Southern California many years ago to turn our great rivers into flood control channels,” said Patzert. “Remember, there’s only one thing that’s more important in California than water — real estate!”

The state’s largest reservoirs are in Northern California where El Niño storms are much less likely to hit.

Pacific Ocean temperatures are also so warm, NASA hydrologist Jay Famiglietti is worried California will get rain, but not the snow it desperately needs. Why is snow so important?

“Think of it as the big statewide freezer that keeps the water frozen in the mountains over the winter and then lets it thaw out slowly in the Spring and trickle down into the reservoirs,” said Famiglietti. “So without snow there’s nothing to melt.”

That could leave those reservoirs low and dry.

No matter what happens, scientists say it will most certainly take more than one wet El Niño winter to bust four years of drought.

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