Meteorologists predict that on Wednesday into Thursday, a huge storm that will rapidly strengthen into a bomb cyclone off California will strike the Golden State, unleashing the possibility of life – threatening flooding, severe winds, and power outages.
The storm will hit just a few days after the state experienced devastating flooding and significant snowfall during the holiday weekend, endangering travelers and resulting in hundreds of thousands of power disruptions.
The heaviest precipitation will be fueled by an atmospheric river, or large plume of moisture, that is 2,500 miles away from the tropical Pacific Ocean. Where the atmosphere is cold enough, such a meteorological configuration can cause a wallop of snow that can halt movement as well as severe rain and flooding. As a Pineapple Express, this particular occurrence can be categorized because it will originate close to Hawaii and spread outward.
Porter listed mudslides as one of the risks that may continue for several days even after the rain stops.
“Not only will this storm be severe, it will be drawing on a big atmospheric river, and it is coming only days after the previous storm produced massive rain and significant floods, heightening the impacts and risks that can happen,” he warned.
Strong winds in addition to the high precipitation will increase the threats posed by the storm as it rapidly intensifies, a process known as bombogenesis. A storm has experienced bombogenesis when the barometric pressure drops at least 0.71 of an inch (24 millibars) in 24 hours. Meteorologists will frequently refer to this type of strengthening system as a bomb cyclone.
The California Department of Water Resources announced on Tuesday that it had prepositioned flood-fighting supplies and equipment at 38 different places and had sent out levee inspectors ahead of the rain in anticipation of probable flooding throughout the state.
According to meteorologists, coastal portions of California, north of San Francisco, as well as locations south of San Francisco to mountains just north of Los Angeles, are the areas most at danger for receiving up to 4 inches of rain from the new storm. Tuesday saw the issuance of an evacuation advisory for Watsonville, which is about 50 miles south of San Jose, and a mandatory evacuation order for the southern coastal regions of San Mateo County, which is located about south of San Francisco.
The lower west-facing slopes of the Sierra Nevada in California, which are located from east of Sacramento to just east of Redding, are another area where 4 or more inches of rain are predicted to fall.
Forecasters predict that San Francisco, Sacramento, and Los Angeles will still see flash flooding as a result of the storm’s strong rain. The storm is expected to bring San Francisco between two and four inches of rain, with Sacramento and Los Angeles receiving between one and three inches. A large portion of that rainfall might occur in a timeframe of 12 hours or less, with fast runoff accumulating on nearby streets and roads.
There may be washed-out secondary streets in the area, forcing motorists to take alternate routes, Anderson warned.
Strong winds from this storm, which in some places can reach hurricane force (74 mph or more), will be a major issue as well. As the storm’s barometric pressure drops and air rushes in toward the system’s core, strong winds are produced.
Poorly rooted trees in saturated soil can tumble over due to wind force. There will be power disruptions where utility lines are in the way. The storm may cause power outages for hundreds of thousands of utility users.
In order to prepare for the storm, Anderson advised locals to fill up their cars with petrol, have enough gas to run generators, and stock up on non-perishable food items in case there is a prolonged power outage.
People in parked cars and pedestrians below can sustain significant injuries as tree limbs break or trees fall.
Travel is severely discouraged during the storm’s peak, Anderson added.
According to Anderson, snow levels in the Sierra Nevada will be primarily above pass level on Wednesday before starting to decline Wednesday night and Thursday with several feet of snow, particularly over 7,000 feet. Due to significant snowfall rates, low visibility, and strong gusts, traveling over the higher passes of the Sierra Nevada on Wednesday night into Thursday may become quite challenging.
Due to the likelihood of significant snowfall, I-80 may experience road closures. Over the New Year’s weekend, the route in Sierra Nevada was closed for many hours due to stranded cars and quickly accumulating snow.
Snow levels are forecast to stay above Southern California passes, however Siskiyou Summit along I-5 close to the Oregon/Northern California boundary may get brief snowfall.
The atmospheric river that struck California’s Central and Northern regions The second-highest day rainfall in Downtown San Francisco’s recorded history occurred on Saturday. Only the 5.54 inches of rain that fell on November 5, 1994, followed the 5.46 inches of rain that poured on the city. Records first appear in 1849.
The Central Sierra Snow Lab recorded a startling hourly snowfall rate of around 7.5 inches per hour on Saturday afternoon due to the same configuration, and the high region of the Sierra Nevada received several feet of snow in 12 to 24 hours.
There is no doubt that the flurry of storms will significantly aid in easing the ongoing drought in California and many other Western states. Before the storm train begins to subside later in the month, some reservoir levels may rise to their maximum levels.
Up until the middle of January, there will be a lot more storms that come ashore from the Pacific. Sometimes, the duration between storms might be as low as 12 hours.
According to meteorologists, each of these storms has the potential to bring bouts of the flooding rain at the low elevations and heavy snow in high country. However, many of the storms may not bring much rain to Southern California since the overall storm track is projected to shift more to the north along the West Coast. Oregon and Washington are anticipated to experience an upsurge in storm-related issues.
