Low-lying parts of San Francisco are likely to see urban flooding Friday afternoon after the National Weather Service issued a warning of "life threatening flash flooding."All of San Francisco is under a flash-flood warning Friday until 3:45 pm as the atmospheric river stalls over the SF Peninsula and is potentially dumping some historic levels of rain. A flash-flood advisory is in effect until 8 pm.As recently as 9 am Friday, the National Weather Service was forecasting an inch and a half of rain today in San Francisco, but that has changed, and a few hours later, the Chronicle was warning of 3 to 5 inches of rain — potentially putting today on par with the New Year's Eve rainstorm of 2022, when we had the second-wettest day on record with 5.45 inches of rain in the city.This is due to an intense band of rain that is moving directly over San Francisco and the Peninsula, which is causing urban flooding that is expected to worsen.Now some roadways in the Marina, adjacent to the Bay, are ponding with water, and both motorists and pedestrians are being advised to avoid any areas like this.A Flash Flood Warning is in effect for San Francisco as rain continues to pummel the Bay Area. Here’s a look at the flooding in the Marina District. Live updates here: https://t.co/fhuEsrVMID pic.twitter.com/WFRqStqXE3— LiveDoppler7 (@LiveDoppler7) November 22, 2024 Flash Flood Warning including San Francisco CA until 3:45 PM PST pic.twitter.com/Dwy58FeLbk— NWS Bay Area 🌉 (@NWSBayArea) November 22, 2024 The Chronicle reported that there was a foot of water on part of I-280 in Daly City, leading to a significant traffic problem. KRON4 also reports that two lanes of US-101 northbound are blocked due to flooding in San Francisco, near where 101 and 280 intersect.A video on the Citizen app shows a vehicle stuck in floodwaters at Henry Adams and Alameda streets in the Design District. There was also a report of moderate flooding at Marina Boulevard and Divisadero, which looks to be where the ABC 7 footage above was taken.There are photos coming in from Buena Vista Park, where water is pouring down the steps onto Haight Street at Buena Vista West, causing ponding.Water was also pooling at the foot of Alamo Square Park, where it was also flowing down some steps to the street.Water coming down the steps of Alamo Square Park, November 22, 2024. Photo: SFistMeanwhile, in Santa Rosa near Mark West Springs Road, ABC News had a national correspondent, Matt Gutman, out broadcasting from the floodwaters Thursday, which are gathering over vineyards there. View this post on Instagram A post shared by ABC News (@abcnews) Significant rain is expected to continue falling until about 7 pm.This is a developing story.