In my last post back in September, I discussed the re-appearance of very unusual warmth in the North Pacific in 2018 and 2019, with the focus shifting from northwestern to northeastern parts of the basin during this period. However, it became clear that the warmth was not as well-established in the sub-surface waters as in the earlier iteration of the so-called “Blob” pattern of 2013-2015; … Continue reading Cooler Patterns – For Now
In the wake of truly exceptional summer warmth and dryness in southern Alaska, and increasingly unusual ocean warmth farther south near the west coasts of Canada and the lower 48, there has been something of a revival of interest in North Pacific temperatures and specifically the so-called “Blob” pattern of ocean warmth that first made headlines back in 2014. It’s therefore worth taking a look … Continue reading Has The Blob Returned?
In my last update way back in February, I highlighted a long-range NMME forecast suggesting that extraordinary warmth would develop by summer across much of the North Pacific Ocean. Here’s the sea surface temperature (SST) forecast that caught my attention at the time: The forecast turned out to be fairly good, with the verification map (below) showing some distinct similarities to the forecast – particularly … Continue reading Record North Pacific Warmth
The past six months have been rather quiet for “blob watchers”, as the North Pacific temperature patterns have been mixed and variable. The North Pacific Mode has been oscillating between negative and positive phases with some regularity, and the PDO did the same thing for the second half of 2017 before turning modestly positive so far this year. It’s a bit unusual to have a … Continue reading North Pacific Forecast
Last week a paper by Yu-Chiao Liang and co-authors was published in the Journal of Climate discussing the connection between North Pacific “blob” warming and atmospheric flow patterns spanning the North American continent from the North Pacific to the North Atlantic. Among other interesting results, the authors showed that variations in sea surface temperatures in the “blob” region of the northeastern Pacific are rather closely … Continue reading Atmospheric Connection to the Blob
It’s been about five months now since the North Pacific Mode, a useful measure of the “Blob” spatial pattern, turned negative. Cooler than normal sea surface temperatures across the northern North Pacific (but south of the Bering Sea) kept the NPM in the negative phase all winter, and the December-February average of the NPM index was the lowest since 2000-2001. Here’s a recent weekly SST … Continue reading The Blob in Hibernation
Just a few weeks ago I highlighted the return to a strongly positive phase of the North Pacific Mode (NPM), caused by persistent high pressure over the northeastern Pacific Ocean during summer. Well, it didn’t last long. The circulation pattern has undergone a dramatic reversal, with numerous strong storms across the North Pacific, and sea surface temperatures have dropped precipitously in the “blob” region. The … Continue reading Dramatic Changes in Recent Weeks
Those who follow North Pacific temperature patterns closely are well aware that the past summer brought a dramatic expansion of above-normal temperatures at the ocean surface across the northern North Pacific Ocean, reversing the cold anomalies that developed last winter during the strong El Niño episode. The two maps below illustrate the change, based on OIv2 SST data. The late winter pattern was very characteristic … Continue reading Subsurface Conditions
In my post last month I mentioned that the recent reversal of the North Pacific Mode (NPM) phase was related to this winter’s El Niño event. In other words, when we saw El Niño developing last year, we might have anticipated that “the Blob” would probably lose some of its surface signature over the course of the winter; it wasn’t a surprise. The chart below illustrates … Continue reading Negative NPM Here to Stay?
Carol Janzen and Rick Thoman have graciously invited me to contribute here, and it is a pleasure for me to do so. By way of introduction, I’m Richard James, a meteorologist with Prescient Weather and an Alaska weather enthusiast. Last September I gave a talk about the North Pacific Mode (NPM, “the Blob”) and Alaska winter climate at the University of Alaska Fairbanks – see here for … Continue reading Subsurface Warmth Persists