The Blob is Back

Several of you have asked about it.   Many of you are concerned.  How much of this interest is based on fear or just scientific curiosity, I can't say.   But it is back.  The Blob has regained its strength, and that will be the topic of this blog.

As many of you know from my previous blogs, the Blob is a area of warmer than normal water (sea surface temperature, SST) in the northeast Pacific, originally named by Washington State climatologist and local weather wit, Nick Bond.  The Blob originally formed in late 2013 and then has waxed and waned during the last few years.   Research by Nick Bond and others revealed that the Blob is the love child of persistent high pressure.  High pressure is associated with weaker winds that result in less mixing in the upper ocean (mixing of cold water up to the surface).  It also changes surface ocean currents.

So lets check out the current Pacific SST situation by showing you SST anomaly (difference from normal, in °C).  First, for the first week of July.   The northeast Pacific off our coast was slightly above normal, but nothing exceptional.

But fast forward to a few days ago (Sept 8) and you will notice MUCH warmer temperature over the NE Pacific.   The Blob is back.

Want a closer view?   Here is the sea surface temperature anomaly for yesterday.  Some limited areas reaching 3-4C above normal.  Water is COLDER than normal over California and southern Oregon.   This makes sense because the unusual high pressure offshore that is producing the Blob also results in enhanced northerly winds along the coast, which produces increased upwelling of cold water from below.

As I mentioned, the Blob is produced by enhanced high pressure over the northeast Pacific.  Don't believe this?  Here is the anomaly (difference from normal) for the last 3 months of 500 hPa heights (think of this as pressure  around 18,000 ft).  The red offshore indicates higher heights (pressure) than normal.  Just where the Blob is located.

Or we can look at the difference of sea level pressure from normal for June through August (see below). The bright yellow shows much higher pressure than usual.

So what is the Blob's future?    The NOAA CFSv2 model prediction of SST anomaly for October through December shows a strong Blob offshore (darker red colors).  Warm water along the East Coast are good for hurricanes, by the way.

So the Blob may have some staying power.   Its direct impact on our weather is modest (increases our temperature by 1-2F based on some model experiments I ran) and it has implications for marine life (which is outside my area of expertise).    Let me end by noting that there is no reason to believe that the Blob is associated with global warming, since it is produced by high pressure and lack of vertical mixing in the ocean.

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Announcements: 

New Weather Smartphone App, uWx

At the UW, we have developed a wonderful FREE weather app for Android smartphones that also collects pressure for use in weather forecasting. If you want to try it, please go to the Google PlayStore and download it.

Talk on Northwest Climate Surprises on September 28.

During the evening of September 28, I will be giving a talk in Seattle at UW's Kane Hall on Climate Surprise: Unexpected Impacts of Global Warming on the Pacific Northwest. You think global warming will simply bring warmer temperatures, drought, less snow, and more storms? Think again. The latest climate model simulations provide a far more nuanced prediction of what will happen here, with some of the results quite surprising. This talk is sponsored by CarbonWa and the Audubon Society To find out more or to secure tickets, please go here.