SAN FRANCISCO – Just three days after a record-breaking storm brought significant rain, widespread flooding and significant mountain snow to much of California, one other, even perhaps more powerful double whammy of an atmospheric river and bomb cyclone is targeting the region this week that might change into one among the more impactful storms to strike the state in years. Mandatory evacuation orders have even been issued ahead of the storm for neighborhoods with a high risk of flooding.
On this case, the developing storm will tap into abundant tropical moisture available within the Pacific Ocean, creating a fairly strong “atmospheric river” that may carry copious amounts of moisture from Hawaii to California.
“Mainly, an (atmospheric river) is a river within the sky of water vapor, and when it hits the mountains, (the moisture) is forced up over the mountains,” Marty Ralph, Director of the Center for Western Weather and Water Extremes, told FOX Weather. “That upward motion causes clouds and precipitation to form, and the faster the flow of air and water vapor is hitting the mountains, the faster the rain is falling, so that you get increasingly more rain with the stronger ARs hitting the mountains.”
This specific sort of atmospheric river, generally known as the “Pineapple Express,” in a nod to the storm’s fuel source because of its Hawaiian origins, is ready to bring significant moisture to California. Consider this as a narrow pipeline of moisture that originates within the tropics.
Flood Watches span much of the state, from near the Oregon/California border to simply north of the Los Angeles area.
Some areas along the northern and central California coast could see 5-8 inches of rain, while farther inland, rainfall totals within the mountains and their foothills could approach 8-12 inches in some spots.
The San Francisco area, which saw its second-wettest day on Latest Yr’s Eve, could see a further 2-5 inches of rain with locally higher amounts. Even the Los Angeles area could have 1-3 inches of rain – with as much as 6 inches possible within the Southern California mountains – by the point the storm system moves through.
“A whole lot of the main target was on the Sacramento Valley, the Bay Area and the San Joaquin Valley, but LA, prepare,” said FOX Weather meteorologist Britta Merwin. “We got rain on the way in which, and it’s going to be moving in as we go into Thursday morning.”
Since atmospheric rivers have been dropping near record amounts of rain and snow across California since before the Christmas holiday, forecasters worry additional heavy rain may lead to more flooding and landslides.
‘Likely lack of human life’ from atmospheric river impacts
Meanwhile, the bomb cyclone will create an amazing difference in pressure across regions, resulting in widespread strong wind events that might last for several hours.
High Wind Watches span much of the state into Thursday morning for gusts to 50 mph within the San Francisco Bay Area, 55 mph gusts within the Sacramento Valley and 65-70 mph gusts possible along the coastal and mountainous regions.
With heavily saturated grounds and hours of such wind speeds, several falling trees and power outages are likely. There is also potential damage from flooding and mudslides.
National Weather Service forecasters in San Francisco weren’t mincing words concerning the upcoming threat.
“To place it simply, this can likely be some of the impactful systems on a widespread scale that this meteorologist has seen in a protracted while,” an NWS meteorologist in San Francisco wrote of their forecast discussion Monday evening. “The impacts will include widespread flooding, roads washing out, hillside collapsing, trees down (potentially full groves), widespread power outages, immediate disruption to commerce, and the worst of all, likely lack of human life. This is really a brutal system that we’re taking a look at and desires to be taken seriously.”
While rain will fall on the lower elevations across the West, as you get higher in elevation, snow is anticipated. A number of the highest peaks of the Sierra Nevada could see a further 2-3 feet of snow by Friday when the storm systems move through.
There is no such thing as a (sun)light at the top of the tunnel yet
This latest storm will eventually push through by late Thursday or Friday, but there may be scant hope for drier weather within the Golden State anytime soon.
One other robust storm system is eyeing the state for the weekend, and prolonged forecasts suggest additional rain is probably going on multiple days next week, adding one other several inches of precipitation to the state.
Despite relentless atmospheric rivers, drought still consider California
Several inches of rain within the forecast on top of what’s already fallen this winter is definitely appreciated in a region mired in a years long drought. While every drop helps, the realm has a protracted solution to go.
“At this cut-off date, we still have one other 4 or five months in our snow season and in our typical rainy season,” Andrew Schwartz, lead scientist on the Central Sierra Snow Lab, said last week. “That signifies that while we’re form of scoring the touchdown in the primary quarter of the sport. Right away, we still have three-quarters left, and there’s so much that may occur.”
Schwartz said last yr’s winter season began well with a record-breaking December mountain snowfall.
“But January through March form of shut off, and we didn’t see as much precipitation come through in that period as we might have wanted,” he s
Even a median snowfall season wouldn’t be enough to get the region out of drought.
“At this cut-off date, we realistically need about an additional winter’s price of precipitation,” Schwartz said. “So, it’s not going to occur in a single yr. At minimum, we’re probably taking a look at three to 4 of above-average before we are able to really speak about getting out of the drought.”
In a median season, the lab sees 30 feet of snow. An additional season’s price of snow would mean 60 feet in a single yr. He said it’s a “high task to attempt to tackle.”