Updraft® - Minnesota Weather News

El Niño driven rains to deluge Southern California

El Niño has yet to be officially declared by the National Oceanic and Atmospheric Administration but the weather maps may already be ahead of the game. Recent atmospheric circulation patterns over the Pacific and North America are starting to look more like a typical El Niño year.

A significant "atmospheric river" event is setting up to deliver a firehose of rainfall to southern California in the next 48 hours. Rainfall totals may reach 2 to 5 inches in the mountains of southern California and will likely trigger flooding and mudslides.

Tracking the pineapple express

The delivery system pipeline for the moisture from the tropical Pacific looks suspiciously like those we meteorologists call the "pineapple express." Pineapple express events are renowned for delivering significant multi-inch rainfall totals to California in El Niño winters.

Today's GOES West infrared color enhanced loop shows a powerful upper level low pressure center swirling off the west coast, and a sub-tropical moisture plume getting sucked underneath.

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NOAA

That plume will deliver soaking, even heavy rainfall to southern California in the next 48 hours. The San Diego National Weather Service highlights the expected 2 to 5 inch rainfall totals.

Flash flood watches are up through Wednesday morning for a big chunk of southern California.

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NWS San Diego

From drought to flood in 48 hours? Only in California. Keep an eye on your national newscasts.

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US Drought Monitor. USDA/UNL

It will take anywhere from 7 to 12-plus inches of rain and copious mountain snowfall totals to end the drought in California, so multiple storms will be needed to ease California's historic drought. For now, the NOAA seven-day rainfall totals forecast is a welcome development for the drought weary West Coast.

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NOAA

The abrupt changes to a much wetter pineapple express driven pattern in California may be the beginning of the end of one of the worst droughts in the modern California record that began nearly two years ago.

It may also be a sign that the stealthy El Niño of late 2014 is already here. This meteorologist thinks you may hear El Niño "officially" declared in the next few weeks, days, or even hours.

The Australian Bureau of Meteorology will issue an update overnight and may push the needle even closer to the point where we can declare that El Niño has indeed already arrived.