California braces for historic winter as Super El Niño and climate change converge

Key points

• NOAA reports a 100% chance of a strong El Niño persisting through March, with an 83% probability it will rank among the most powerful since 1950.
• Climate scientist Daniel Swain estimates a 10% risk of a flood costing over $10 billion, which would be California's costliest on record.
• Sea levels in Los Angeles have risen 9.5 inches since May due to a Kelvin wave, with water levels currently 1-2 feet above expected.
• King tides are scheduled for November 24-26, December 22-25, and January 20-23, 2027, posing high risks of coastal flooding.
• FEMA has lost 17% of its staff since 2025, and federal disaster aid approval rates for blue states are significantly lower than for red states.

Background

The 2026 El Niño event has already shattered Pacific temperature records, with sea surface anomalies reaching 3.8°C above normal. Previous forecasts indicated a 98% chance of a very strong event, with peak ocean temperature anomalies projected to exceed 4.1°C. Governor Newsom declared a state of emergency in September to prepare for potential coastal flooding and erosion, particularly in San Diego.

How outlets are covering it

Yale Climate Connections emphasizes the scientific probability of a record-wet winter, citing model forecasts that show a 13% chance of the wettest winter on record. It highlights the compounding effects of climate change, which has tripled the risk of a trillion-dollar megaflood. The Mercury News focuses on local preparedness in San Jose, noting that officials are fortifying creeks and expanding emergency operations centers. However, it raises concerns about the lack of federal support, with Rep. Sam Liccardo pointing to job cuts at FEMA and blocked disaster mitigation grants. While Yale Climate Connections warns of widespread, historic coastal flooding, The Mercury News highlights the specific challenges of urban infrastructure and the potential for delayed emergency responses, as seen in the 2017 floods.

Why it matters

The convergence of a Super El Niño and climate change poses a severe threat to California's infrastructure, economy, and population. The potential for record rainfall and rising sea levels could lead to catastrophic flooding, with significant financial and human costs. The reduced capacity of federal agencies like FEMA and the uneven distribution of disaster aid exacerbate the risks for vulnerable communities, particularly in blue states. Effective local preparation and coordination are crucial to mitigating the impact of these extreme weather events.

What to watch

Monitor the progression of the El Niño event and its impact on sea levels and rainfall patterns. Watch for the king tides in November, December, and January, which could trigger coastal flooding. Assess the effectiveness of local emergency response systems and infrastructure upgrades in cities like San Jose. Track federal disaster aid approvals and the capacity of FEMA to respond to potential disasters. Evaluate the long-term impacts of climate change on California's flood risk and the need for continued adaptation measures.