OXNARD (CBSLA)  —  Where is all this water coming from?

The sky is the easy answer, but it’s not the only one.

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The recent storms, and Thursday’s in particular, seem relentless, creating problems and dangerous situations all across the Southland.

A woman had to be rescued from her car after it sank into flood waters in Anaheim. A San Bernardino County Sheriff’s helicopter crew pulled two people from the Santa Ana River. The Via Verde Golf Course in San Dimas was flooded out.

Meteorologists say an atmospheric river fueled all the rain. It’s a long narrow stream of tropical moisture in the atmosphere that can result in heavy rain or snowfall.

It’s not been that cold. That’s because it’s all part of a system called “The Pineapple Express.”

KCAL9’s Rachel Kim spoke to National Weather Service Meteorologist Carol Smith to find out what’s causing all the water.

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“You can think of it also, on a day like today, when it’s so much water and the winds are strong, it’s almost like a fire hose that’s pointed on our coastline,” Smith says.

These atmospheric rivers are responsible for 30-50 percent of our rainfall. The strength of this event was unusual because of the amount of moisture that it brought.

“We’ve had a vigorous upper level low and cold front and the combination of those two things and the strong southerly flow just gave us a long duration of very heavy sustained rain rates,” Smith says.

Translation: too much water falling too fast.

Smith told Kim she wasn’t surprised to see the flooding and mud flows across the area today considering those rain rates.

“The entire seasonal normal is actually 14.93 inches for the whole season. So now, it’s February, we’ve already exceeded that value,” Smith says.

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Meteorologists at the NWS say this atmospheric river event is pretty much over. They’re now focusing on storms headed our way Friday and Sunday. They expect these storms to be drier but much colder.