UW Weather Prof: The "Blob" is back
SEATTLE -- I guess it's apropos this Halloween "scary movie" season that just when you thought a meteorological villain was totally vanquished a few years ago, here comes the sequel.
Another "Blob" of warm water (about 3-4 degrees F above normal) has spawned in the northern Pacific Ocean, according to University of Washington Atmospheric Sciences Professor Cliff Mass.
Those that have been around here a few years might remember the first "Blob" -- a huge pool of warm water that formed in the northeastern Pacific Ocean in 2014 and 2015 and hung around for several months. As much of our weather comes from that region, the Blob (in tandem with one of the strongest El Nino's on record) was blamed for contributing to 2015 being the hottest year on record in Seattle, featuring a very mild winter (the final sub-50 degree high temperature that year occurred on Feb. 1), a very low mountain snowpack season (Snoqualmie Pass had just 104 inches of seasonal snow, about a quarter of normal) transitioning to the hottest summer on record (although that was nearly matched this past summer.)
What's causing this Blob -- or "son of Blob" as Mass is calling it? Another surprisingly resilient ridge of high pressure over the Gulf of Alaska and northeastern Pacific Ocean that just won't let go.
"Persistent high pressure is associated with lighter winds. Such light winds result in less mixing in the upper layer of the ocean, so less cooler water from below is mixed to the surface," Mass wrote in his weather blog, crediting fellow UW Professor Nick Bond and his colleagues for much of the research into The Blob. "The result? A warm water anomaly and the rebirth of the BLOB."
The 2015 version of The Blob lasted over a year before finally surrendering. How long will this Blob last? Hopefully not as long.
"As this point, it looks like things are evolving to a pattern with less high pressure offshore, so the BLOB should weaken," Mass wrote, adding with a bit of Halloween dark humor and, I picture, some imagined horror movie music in the background: "Unless is doesn't!"
But with El Niño now a strong odds-on favorite for this winter, Blob or no Blob, the signs were already leaning toward a mild winter. NOAA is scheduled to release its official winter forecast Thursday and it's expected to predict overall mild and drier than normal conditions in the Pacific Northwest.