![Atmospheric River Storm: Impacts & Forecast for [Region]](https://www.mercurynews.com/wp-content/uploads/2024/11/SJM-L-STORM-1123-3.jpg?w=1024&h=683 "Atmospheric River Storm: Impacts & Forecast for [Region]")
Atmospheric River Set too Impact Bay Area: What to Expect (November 2025)
the Bay Area is bracing for its second atmospheric river event of November, a “moderate scale” storm poised to arrive Wednesday evening and linger for approximately 24 hours.This system, currently developing off the coast, promises a potent mix of strong winds, heavy rainfall, and even the possibility of thunderstorms for some locations. Here’s a detailed breakdown of what residents can anticipate.
Understanding the System
Atmospheric rivers are concentrated bands of moisture in the atmosphere, capable of delivering significant precipitation. This particular storm is developing rapidly as a strong cold front interacts wiht existing high-pressure systems. This collision will create atmospheric instability, fueling the intensity of the approaching weather.
Wind Warnings & Advisories
The National Weather Service (NWS) has issued the following alerts:
* high Wind Warning: north Bay counties are under a High Wind Warning from 10 PM Wednesday to 10 AM Thursday.
* Wind Advisory: A wind Advisory is in effect for the remainder of the Bay Area during the same timeframe.
Expect sustained southerly winds of 15-25 mph, with gusts possibly reaching 50 mph in Alameda, Contra Costa, San Mateo, and Santa Cruz counties. The North Bay, including Sonoma and Napa, could see even stronger winds – steady at 20-30 mph with gusts up to 60 mph. Secure outdoor objects and be prepared for potential power outages.
Rainfall Forecast: Where Will It Hit Hardest?
Most of the bay Area has at least a 50% chance of receiving an inch or more of rainfall. However, the distribution won’t be uniform.
* North Bay (above Santa Rosa): A nearly 50% chance of 2+ inches of rain.
* Santa Clara Valley (San Jose), Concord, Livermore: These areas, sheltered by mountains, will experience a “rain shadow” effect, reducing precipitation chances to around 20%.
* Remainder of the Region: Expect heavy downpours in many locations.
The rain shadow phenomenon occurs as the atmospheric river is forced to rise over mountains, releasing much of its moisture on the windward side and leaving less for areas leeward.
Sierra Nevada Impact: Winter Storm Advisory
The storm will also significantly impact the Sierra Nevada. A Winter Storm Advisory is in effect above 8,000 feet and for the Greater Lake Tahoe area from 1 AM Thursday to 7 AM Friday.
* Snowfall: 4 inches of snow are expected between 7,500 and 8,000 feet, with up to 6 inches above 8,000 feet.
* Wind: Gusts near Lake Tahoe could reach 30-40 mph, with potential for 90 mph gusts at higher elevations.
* Travel: Expect significant travel disruptions through the Sierra passes on Thursday.
Timing & Duration
Meteorologist Rick Canepa of the NWS notes the storm’s relatively slow movement. This suggests a later arrival Wednesday evening and a lingering presence into Thursday afternoon. While the main event will conclude Thursday, isolated showers are possible afterward.
staying Informed & Prepared
This atmospheric river, while moderate in scale, demands preparation. Stay updated with the latest forecasts from the National Weather Service (https://www.weather.gov/) and local news sources. Consider these steps:
* Secure loose outdoor items.
* Be prepared for potential power outages.
* Avoid unnecessary travel, especially in the North Bay and Sierra Nevada.
* Monitor local conditions and heed any warnings or advisories.
This storm serves as a reminder of the dynamic weather patterns impacting california. Staying informed and prepared is crucial for navigating these events safely and effectively.
