The Return of the Blob
If you are a skier, fisher or weather geek, you remember the Blob of late 2013–mid-2015. The Blob was an extensive area of sterile and much warmer-than-average water in Northeast Pacific, and the Blob wreaked havoc on our marine ecosystem and mountain snowpack. I remember how skinny the Coho salmon we caught in Puget Sound were during autumn 2014, and I still get nightmares about how bare the mountains were during the dreadful 2014–2015 ski season. With only 104” inches of the white stuff for the entire year and well-above-average temperatures, the Summit at Snoqualmie even had trouble keeping their tubing center open!
Unfortunately, the Blob is back. Blob 2.0 began building in June and now extends throughout much of Northeast Pacific, though it has weakened in recent weeks. Like the last one, Blob 2.0 was caused by a persistent ridge of high pressure over the Eastern Pacific. With no storms to churn the water column and above-average sunshine, the water column became stratified, with warm, nutrient-poor water near the surface and cooler and more nutrient-rich water at depth. Despite the Blob being less than 50 meters deep in most spots, sea-surface temperatures are as much as 3–4 degrees above-normal, and this has huge implications for our weather and the marine life off our coast. The albacore tuna fishing has been top-notch this year, but the salmon fishing hasn’t been great.
And although 2019 didn’t feature the brutal heat waves and fires of the past two summers, Blob 2.0 caused our nighttime temperatures to be much warmer-than-normal, even during the few cool periods during the summer when highs were well-below average. In fact, Sea-Tac experienced 79 consecutive days with low of 55 or higher (6/28–9/15), shattering the record of 52 days set during 2013. The Blob warmed our temperatures in two ways: the onshore flow from the Pacific was warmer than normal, and our airmass was more humid since warmer air can hold more water vapor. Water vapor is a powerful greenhouse gas and helps prevent heat from escaping to space, and its effects are most noticeable at night when there is no incoming radiation from the sun. That’s why the Gulf Coast states have such hot, sticky nights, while high-elevation deserts cool dramatically after the sun sets.
Because these Blobs are so shallow, it only takes a few weeks of active weather over the Blob to mix the ocean and bring temperatures and nutrients closer to normal. September was an extremely wet month with lots of troughing over the NE Pacific, and thus, the Blob has decreased in strength. For skiers and salmon alike, let’s hope it continues to dissipate throughout October!
Charlie Phillips, a Madrona resident, received his B.S. in atmospheric sciences from the University of Washington and works in Portland as a meteorologist. Check out his weather website at to charlie.weathertogether.net.