Ingalls Weather<p><strong>Is La Niña returning Fall 2025?</strong></p><p>Winter 2024-25 came with a short-lived and weak La Niña that waned in the Spring. Since then, the equatorial Pacific has been settled in what we call an ENSO neutral pattern (meaning that we are not experiencing El Niño or La Niña).</p><p>Some modeling has hinted toward La Niña making a return around October or November of this year. Along with this, a few online weather sources have latched onto the La Niña train and the hype that it contains.</p><blockquote><p><em>Ingalls Weather thanks the support it gets from donors. Please consider making a small donation </em><a href="https://ingallswx.com/donate/" rel="nofollow noopener" target="_blank">at this link</a><em> to help me pay for the website and access to premium weather data.</em></p></blockquote>NOAA Climate Prediction Center forecast ENSO category chances. (NOAA)<p>The NOAA Climate Prediction Center is not sold on the idea of an impeding La Niña and neither am I. It is true that they slightly favor the emergence of La Niña October or November but it appears to be fairly short lived with ENSO neutral conditions returning around the New Year.</p><p>For the Climate Prediction Center to officially forecast a La Niña (or El Niño) event, they need to be favoring those conditions for five consecutive three month periods. Their latest forecast, issued July 10, only has two consecutive periods.</p> <p>Type your email…</p><p>Subscribe</p> Various weather model views on ENSO conditions through the end of the year. (StormVista)<p>To reach La Niña, the equatorial Pacific needs to have sea surface temperatures 0.5°C or cooler below average. We might tap that around October or November but the consensus is definitely closer to neutral conditions.</p><p>La Niña can be exciting in the Pacific Northwest because it can bring cooler weather and above average precipitation in the winter. Unfortunately for lovers of Cascade concrete this doesn’t seem the case for this year. There will certainly still be mountain snow, and there are other features that drive regional weather, but La Niña doesn’t appear to be one of those relevant drivers.</p><p>ENSO neutral years can bring plenty of exciting weather to Washington, Oregon, and British Columbia, however. Evidence suggests that fall wind storms are more common during ENSO neutral falls than under other ENSO categories. With this comes a higher risk (but not a guarantee) of a severe wind storm.</p><p>Despite early forecasts to the contrary, Fall 2024 came in ENSO neutral. We had plenty of fall storms including a particularly robust atmospheric river aimed at the Lower Mainland. These storms kept temperatures mild into December as the mean flow was out of the southwest.</p><p>Fall 2025 certainly won’t be exactly the same as Fall 2024 but the storm pattern could be fairly similar in scope. Even if La Niña conditions briefly emerge, it’s more likely to seem like an ENSO neutral fall rather than a La Niña fall because of how weak it appears to be.</p><p>ENSO, or the El Niño Southern Oscillation, refers to sea surface temperatures in the equatorial Pacific. The primary region meteorologists look at for diagnosis is from 120° to 170°W, well to the west of the Ecuadorian coast which sits at around 80°W. El Niño is present when water temperatures are above average and La Niña represents below average water temperatures.</p><p>The oscillation is driven by a number of factors, mainly coming down to how the wind interacts with the sea surface which impacts how much upwelling of cool water occurs on the South American coast. Air pressure values in Tahiti and Darwin, Australia are utilized to aid in diagnosis of the atmospheric pattern.</p><p><em>The featured image is of a bomb cyclone that struck the Pacific Northwest on November 19, 2024. (University of Wisconsin/NOAA)</em></p><p><a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://ingallswx.com/tag/bcstorm/" target="_blank">#BCstorm</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://ingallswx.com/tag/enso/" target="_blank">#ENSO</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://ingallswx.com/tag/orwx/" target="_blank">#orwx</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://ingallswx.com/tag/wawx/" target="_blank">#wawx</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://ingallswx.com/tag/weather/" target="_blank">#Weather</a></p>