Record North Pacific Warmth

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

North Pacific Forecast

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

Atmospheric Connection to the Blob

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

The Blob in Hibernation

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

Dramatic Changes in Recent Weeks

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

Subsurface Conditions

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