An atmospheric river is currently impacting portions of California, with meteorologists predicting that multiple inches of rain will saturate the region until the storm dissipates due to a lack of moisture by Wednesday morning. According to the National Weather Service’s forecast on Tuesday morning, the atmospheric river is anticipated to gradually shift southward throughout the middle of the week as several waves of low pressure move along the front, facilitating the transport of significant moisture from the Pacific Ocean into the coastal areas, parts of the Central Valley, and the foothills of the Sierra Nevada mountain range.
The weather service has indicated that this influx of moisture will lead to further heavy rainfall in the area, heightening concerns of potential flooding, including in the Bay Area. The NWS stated on Tuesday that an additional 2 to 4 inches of rain is projected for the coastal regions, while the Sierra Nevada foothills could experience between 3 to 6+ inches of rainfall. The Weather Prediction Center has issued a Slight Risk (level 2 out of 4) of excessive rainfall for the region to account for these conditions, as mentioned by the weather service.
A Flood Watch is presently in place for the Bay Area and Central Coast until 4 a.m. local time on Wednesday, as communicated by the NWS office in San Francisco. The excessive runoff resulting from the heavy precipitation may lead to the flooding of rivers, creeks, streams, low-lying areas, flood-prone locations, as well as urban regions with poor drainage systems. The NWS has emphasized that the potential for flooding necessitates vigilance on the part of residents living in these areas, encouraging them to be prepared to take necessary actions in the event of flooding.
The NWS office in Sacramento also highlighted on Tuesday that widespread precipitation is expected to resume today and persist through the middle of the week as another weather system traverses the region. Some areas near Sacramento could witness up to 6 inches of rain, according to the weather service. Residents are advised to stay updated on the latest forecasts and remain alert for potential Flood Advisories/Warnings.
Those residing in flood-prone regions are strongly urged to be prepared to respond promptly should flooding occur, as reiterated by the NWS. For further insights, readers can explore the impacts of the Polar Express as it drenches California and the Northwest.
Additionally, over the weekend heavy rains led to the flooding of a residence on Shady Lane in Anderson on Monday, February 3, 2025. To better understand the phenomenon of atmospheric rivers and the Pineapple Express, we can delve into their characteristics and significance in meteorology.
Atmospheric rivers are prolonged and narrow channels within the Earth’s atmosphere that accumulate moisture from tropical regions near the equator and transport it towards higher latitudes. The National Oceanic and Atmospheric Administration notes that while the size and intensity of atmospheric rivers can vary considerably, on average, they carry an amount of water vapor that
