A powerful winter storm has descended upon the West Coast, bringing with it the dual threat of a "bomb cyclone" and atmospheric river, raising alarm across Northern California and beyond. Just as weather experts warned, this menacing storm system is set to deliver heavy rain, damaging winds, and significant snowfall, leading to potential flooding and power outages. The National Weather Service (NWS) has characterized this combination of phenomena as one of the most intense weather events to strike the region this year.
This potent storm, originating from the Pacific Northwest, is known colloquially as a bomb cyclone—a term used to describe storms characterized by rapid intensification, marked by significant drops in atmospheric pressure over short periods. To be classified as such, the center of the storm must record a drop of at least 24 millibars within 24 hours. Experts have noted the remarkable statistics of this cyclone, which has experienced pressure plummeting to as low as 942 millibars, contributing to its classification as historically intense.
According to the Weather Channel, as the storm traverses the coast, it is pulling moisture from the tropics, creating what meteorologists refer to as an atmospheric river, effectively channeling vast amounts of water vapor directly over California. These atmospheric rivers, described as thin bands of moisture, can lead to extreme rainfall and are responsible for delivering over 90% of the water vapor transported to the mid-latitudes from tropical regions. With the current atmospheric river, rainfall predictions are staggering, with some regions anticipating between 6 to 18 inches of rain.
"This is going to be one of the biggest storms of the season, if not the biggest one we've seen this year," said Eric Lau, meteorologist at the National Weather Service. "The impacts are likely to be significant, particularly across Northern California and southwestern Oregon, where the flooding risks will be heightened."
The storm is expected to span several days, starting with intense rain and wind on Wednesday, November 20, and leading to widespread weather advisories and warnings across the region. Flood advisories have already been issued for areas most likely to experience severe rainfall, including the North Bay, where up to 12 inches of rain is predicted. This could result not only in street flooding but also river flooding, as many regions have saturated soils from prior storm systems.
While Northern California braces for the worst, Southern California isn’t completely off the hook. Although it may seem fortunate to avoid the direct hit, the rest of the state will still encounter inclement weather conditions as the storm system rolls through. "We’re forecasting significant rainfall for this weekend heading toward Southern California," noted Henry DiCarlo, KTLA meteorologist. Disturbances later this week could lead to more widespread weather issues for the southern part of the state, as the storm system aims to move southward over the weekend.
Nature's fury has already wreaked havoc across parts of the Northwest, where intense winds have caused extensive damage. Reports indicate peak gusts reaching upwards of 70 mph, particularly along western coastal and inland areas. The storm has already led to numerous injuries, including two fatalities caused by falling trees, as it swept through the Seattle region earlier this week.
"The high winds are causing trees to fall, blocking roads and downing power lines," said Ian Livingston, meteorologist for the Washington Post. "It's incredibly dangerous out there as the storm continues to develop and move southeast toward California."
With power outages across Oregon and Washington affecting over half a million people, the Pacific Gas and Electric Company (PG&E) has proactively mobilized to prepare for potential outages across Northern California as the winds intensify. The utility company expects tree branches to break under the pressure of the wind and could lead to damage to power lines.
On the other hand, the snowfall brought by the storm could reach levels of up to 8 feet in higher elevations like the Sierra Nevada, transforming the winter wonderland and eliciting excitement among early-season skiers and snowboarders. Mount Shasta, for example, is forecasted to experience more than 100 inches of snow, though such heavy precipitation could result in treacherous travel conditions for mountain passes.
Travelers and commuters alike are being urged to stay updated with the latest weather forecasts, and anyone traveling through airports should be cautious. San Francisco International Airport has reported over 200 delays and nearly 50 cancellations due to reduced visibility and adverse weather. Travel experts recommend checking flight statuses frequently, as continuing storm conditions may lead to more disrupted travel schedules.
Many residents along the California-Oregon border have been advised to secure outdoor items, prepare for power outages, and stay alert for sudden flood warnings. Emergency services have been ramping up their readiness levels to respond to any unforeseen incidents caused by the barrage of rain and wind.
"Safety is our top priority as we navigate through this storm period," emphasized Paul Moreno, PG&E spokesperson. "We are urging everyone to exercise caution—stay indoors whenever possible, and be aware of your surroundings if you must venture outside."
The full force of this storm system will continue to play out over the coming days, with meteorologists closely monitoring its development. Heavy rain, powerful winds, and snow are forecasted to linger across many parts of the West Coast, compounding challenges faced by local communities already grappling with the potential of flooding and power outages. It's going to be one wild ride as nature unleashes its fury, prompting heightened awareness and preparedness from those living within the storm's path.
