A large marine heatwave is gripping the California Current system, pushing sea surface temperatures across Southern California waters well above seasonal norms and drawing comparisons to some of the most damaging ocean warming events in recent decades. NOAA scientists flagged the event with a sea surface temperature anomaly map dated February 13, 2026, showing widespread warm departures along the West Coast. The conditions have raised urgent questions about what prolonged heat could mean for kelp forests, fisheries, and coastal ecosystems already strained by prior warming episodes.
What is verified so far
The federal government’s ocean monitoring apparatus has confirmed that the California Current, stretching from the Pacific Northwest through Southern California, is experiencing another large marine heatwave. Michael Jacox, a scientist at NOAA’s Southwest Fisheries Science Center, is among the researchers tracking the event’s development and expected trajectory. The agency published an official SST anomaly snapshot on February 13, 2026, documenting the spatial extent of the warming and indicating that large portions of the coastal ocean are above the threshold used to define a heatwave.
NOAA’s California Current Marine Heatwave Tracker, sometimes called the “Blobtracker,” provides additional granularity on how the event is unfolding. The online tool compiles regional anomaly statistics and counts of record-breaking warm days for subregions, including offshore Southern California. Those figures place the current event in the same general league as two historical benchmarks that reshaped West Coast marine ecosystems: the 1997-98 El Niño and the 2014-15 “Blob,” a persistent mass of warm water that devastated marine life from Alaska to Baja California.
On the measurement side, the data pipeline behind these assessments is well documented. NOAA’s National Centers for Environmental Information calculates marine heatwave metrics using the Optimum Interpolation SST product, a 0.25-degree daily Climate Data Record (version 2.1) that blends inputs from satellites, ships, buoys, and Argo floats. This dataset applies interpolation techniques and bias-corrects its readings against buoy observations, which helps provide a consistent baseline for detecting departures from normal conditions along the West Coast.
The underlying gridded fields come from AVHRR satellite observations and related sources, compiled into netCDF files such as the OISST archive maintained by NCEI. Researchers use these daily fields to calculate anomalies relative to a climatological average and to track how the intensity and footprint of a marine heatwave evolve over time. Because the product is updated continuously, it allows agencies to compare current conditions with past extremes on a like-for-like basis.
To qualify as a marine heatwave under the standard scientific framework, water temperatures must exceed a seasonally varying 90th percentile threshold for five or more consecutive days. That definition comes from a peer‑reviewed classification published in Progress in Oceanography by Hobday and colleagues in 2016, which established event categories and intensity metrics now used globally. NOAA’s ecosystem status pages confirm that they follow this same protocol when identifying marine heatwaves in the California Current and other U.S. waters, ensuring that events are comparable across regions and years.
Nearshore monitoring stations add a ground-truth layer to the satellite-derived picture. Station LJAC1, located at La Jolla near the Scripps Pier, provides in-situ sea surface temperature readings as part of the National Data Buoy Center network. The station page for LJAC1 observations shows recent water temperatures, sensor status, and metadata describing how the measurements are collected. These continuous records allow scientists to check whether the gridded OISST product is accurately capturing rapid swings or localized extremes that can develop along the Southern California coast.
Taken together, these lines of evidence establish several points that are not in dispute. Sea surface temperatures along the California Current are significantly above normal over a large area; the anomalies meet the formal criteria for a marine heatwave; and the event is strong enough, in both magnitude and duration, to warrant comparison with some of the most notable warm periods of the last three decades. The monitoring infrastructure, from satellites to pier-based thermometers, is operating as intended and providing a coherent picture of unusual warmth.
What remains uncertain
Several important questions about this marine heatwave lack clear answers. No verified, peer-reviewed projection specific to Southern California has established how long the current event will persist or how intense it may become through spring and summer. Broader West Coast model outlooks exist, but translating regional forecasts into precise local timelines involves significant uncertainty, particularly because marine heatwaves can intensify, stall, or dissipate depending on atmospheric patterns that shift on weekly timescales.
Ecological impacts remain largely inferred from past events rather than documented in real time. The 2014-15 Blob triggered mass die-offs of sea lions, toxic algal blooms that shut down crab fisheries, and widespread kelp forest collapse. Whether the current warming will produce similar cascading effects depends on factors that scientists are still measuring: the depth of the warm layer, how quickly upwelling winds return, and the baseline health of species that were already weakened by previous heatwaves. As of the latest available monitoring data, there is no primary-source reporting confirming specific fishery catch declines, large-scale strandings, or species die-offs that can be directly attributed to this event.
Local institutional responses also remain unclear. While NOAA has published monitoring data and scientific framing, there is no verified public statement from Southern California research institutions such as Scripps Institution of Oceanography detailing active mitigation strategies or emergency research deployments tied explicitly to the current conditions. That gap matters because nearshore ecosystems along the San Diego and Los Angeles coastlines support both commercial fisheries and tourism economies that experienced substantial financial impacts during past marine heatwaves.
The comparison to the 1997-98 El Niño and the 2014-15 Blob, while useful for context, can also mislead if taken too literally. Each event had distinct drivers. The 1997-98 episode was tied to one of the strongest El Niño cycles on record, while the Blob was driven primarily by persistent high-pressure atmospheric ridging that suppressed normal ocean mixing. Whether the current heatwave shares a dominant driver with either predecessor, or instead reflects a different configuration of atmosphere–ocean coupling on top of long-term background warming, has not been resolved in the available reporting. Without a clear diagnosis of the underlying cause, it is difficult to say whether similar biological responses should be expected.
Another open question concerns vertical structure. Satellite products and OISST maps describe the surface, but many ecological impacts depend on how deep the anomalously warm layer extends. If the warmth is confined to a shallow surface cap, strong upwelling could eventually reintroduce cooler, nutrient-rich water to the euphotic zone. If instead the anomalies penetrate tens of meters or more, the heatwave could more thoroughly disrupt nutrient delivery and oxygen levels, with more severe consequences for plankton, fish, and invertebrates. The current public datasets do not yet provide a comprehensive, depth-resolved view for Southern California.
How to read the evidence
Not all evidence carries equal weight when assessing a marine heatwave, and the current information environment around Southern California’s warm waters illustrates why. The strongest claims rest on directly measured data: satellite-derived SST fields processed through the OISST Climate Data Record and in-situ temperature readings from stations like LJAC1 at La Jolla. These observations, subjected to documented quality-control procedures, support confident statements that the ocean surface is significantly warmer than normal over a broad region.
Derived products, such as anomaly maps, time series of heatwave intensity, and counts of record-breaking days, sit one step removed but remain robust when their methods are transparent. The California Current heatwave tracker, for example, builds on the Hobday definition to categorize events by duration and strength. When these products show that current anomalies rival those of the 1997-98 El Niño or the 2014-15 Blob, the comparison reflects a consistent analytical framework rather than a loose analogy.
Greater caution is warranted when moving from physical measurements to ecological forecasts. Statements that kelp forests “will” collapse or that fisheries “will” see specific percentage declines extend beyond what the present data can guarantee. Past heatwaves provide a warning that such outcomes are plausible, but the response of any given ecosystem depends on local conditions, management actions, and chance. In this context, it is more accurate to describe a heightened risk of harmful algal blooms, marine mammal strandings, or fishery disruptions than to assert that they are inevitable.
Similarly, attributions of cause should distinguish between what is known and what remains speculative. The presence of a marine heatwave is firmly established; the precise roles of El Niño–Southern Oscillation, atmospheric blocking patterns, and long-term climate change in shaping this particular event are still being analyzed. Until formal attribution studies are completed, explanations that lean heavily on one driver or another should be treated as hypotheses rather than settled fact.
For coastal communities and decision-makers, the most reliable guidance comes from integrating multiple strands of evidence: real-time temperature observations, standardized heatwave metrics, and carefully framed lessons from prior events. This combined view supports proactive monitoring of sensitive species and fisheries, without overstating what the science can currently say about the ultimate trajectory of the 2026 marine heatwave in Southern California.
More from Morning Overview
*This article was researched with the help of AI, with human editors creating the final content.
