Days of heavy rainfall and melting snow that triggered Flash Flood Emergencies and that were blamed for the deaths of at least two people could return to the Golden State as another atmospheric event gears up over the moisture-laden Pacific.
The weekend brought a period of respite for millions of Californians who were under flood alerts and saw rainfall amounts that reached 12 inches in some communities.
“What we’re seeing right now, by the way, is the first atmospheric river. Keep in mind that we have another atmosphere that’s on the way, and just one of those atmospheric rivers can carry as much water as 20 Mississippi Rivers,” said FOX Weather meteorologist Michael Estime.
DEADLY CALIFORNIA ATMOSPHERIC RIVER CAUSES EVACUATIONS AS FLOODING WREAKS HAVOC ON STATE
NOAA’s Weather Prediction Center has already warned of a moderate risk for excessive rainfall and has highlighted areas from around San Francisco to Sacramento and points northward for seeing the highest risk of flooding on Monday.
On Tuesday, the greatest threat zone will sink south and include much of Central California.
In zones where flash flooding is considered “very likely,” there is at least a 40 percent chance that precipitation could become problematic within 25 miles of a given point.
Energy that will make up the next event is northwest of Hawaii. As the atmospheric river advances towards California, the FOX Forecast Center expects the system to strengthen and be capable of producing similar impacts to the events already seen in March.
The low-pressure system is expected to approach the coastline during the start of the workweek, and out ahead of it, gusty winds could impact large parts of the West, providing only some temporary relief from the wet weather.
The core of the system is expected to start impacting the Golden State late Monday and will last through Tuesday and into early Wednesday.
“Tuesday morning is when I think we’ll see the heaviest of that rain, just bullseye parts of Redding, California, toward Napa Valley and then work its way down the coast from Sacramento through San Francisco,” said Esteme.
Beyond Wednesday, forecast models show the low-pressure system moving through the Rockies and eventually the Great Lakes.
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Rainfall is expected to bring another considerable flooding threat to elevations below 5,000 feet to Northern and Central California. This includes the San Joaquin and Sacramento valleys, southern Sierra Nevada foothills and the coastal region from San Francisco to the north of San Diego.
Forecast models show between 1 to 3 inches of rain for many communities, with a few spots, especially along the coast and the foothills, possibly receiving more.
Where rain and snowmelt meet, creeks and streams vulnerable to flooding are expected to have a renewed threat.
Before the event begins, around a dozen major river gauges were either near flood stage or above.
In addition to the flood threat, authorities warn that the already saturated ground could lead to the toppling of trees and additional power outages. Winds of 20 to 30 mph with gusts to 40-60 mph could be widespread throughout the state, especially on Tuesday.
The deep moisture is expected to lead to snowfall amounts of a few feet in parts of the Sierra Nevada.
The expected wintry precipitation will make travel nearly impossible on some roadways. Avalanche threats are expected to remain high throughout the week with the additional snowpack and winds.
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