Forget the 'warm blob' -- opposite 'cool blob' taking up roost in Pacific Ocean
It was the darling of the extended record warm stretch of weather we had in 2015 -- a pool of warm waters that had formed off our coast in the Pacific Ocean, given the nickname "The Blob" by our state climatologist.
The warm blob is long gone -- you might have noticed it wasn't like 55 degrees every day in winter. But now it appears we have the opposite effect going, albeit it in much weaker form.
Measurements of sea surface temperatures off our coast in the Northeastern Pacific Ocean are now showing cooler than normal temperatures. (I don't want to call it an "anti-blob" since it's still technically a blob. Maybe we name it "Henry"? It seems giving regular names to natural events is all the rage this year...)
The warm blob was thought to have formed by a lack of storminess in the Gulf of Alaska during the autumn of 2014 and that stagnant water didn't allow cooler water from the deeper parts of the ocean to mix to the top. Generally persistent high pressure for months kept seas calm.
This year's "Henry" was likely caused by a few factors.
"The cold anomalies off the coast of the Pacific Northwest are certainly due to the atmospheric forcing over the last 6-8 months -- and in particular related to the rather impressive winter and spring that we enjoyed around here," said UW's Nick Bond, who also serves as our state climatologist.
Researcher Nate Mantua with NOAA’s Southwest Fisheries Science Center notes that the northeastern Pacific was under a persistent north wind for much of the fall and winter (and early spring.)
"That big patch of anomalously strong winds from the north are likely the primary agent of the cooling that’s taken place," he said.
Both add that the wind anomalies from the north in that region are consistent with La Nina, which was around for last fall and winter.
Not only do those north winds bring in colder air from near Alaska, helping refrigerate the water a bit, it pushes the ocean waters south, drawing in colder water from near Alaska as well. Plus, the churning of the waters from the stormy weather also had a part in the cooling process.
"It is safe to say that the large-scale weather patterns that brought us cooler and wetter conditions also cooled off the ocean," Bond said. "In turn, the cooler ocean did stack the deck in a small way towards cooler temperatures. "
How much? The cool blob is just a couple degrees cooler than normal and Bond estimates it maybe roughly had about one degree of cooling influence in our winter and spring average temperatures -- not a lot, but perhaps a little noticeable.
On the other hand, warm blob had temps about 5-7 degrees above normal, helping provide a virtual "electric blanket" of heating to our weather, not to mention moderating temperatures of incoming weather systems that traversed the "Blob."
Bond did note that we can't blame the soggy weather on the cool blob though.
"There is little observational or theoretical evidence that the ocean temperatures off our coast have much if any impact on precipitation in the Pacific NW," Bond said.
Sun fans probably just have to blame their bad luck is was a La Nina winter on that one...