By Yasemin Saplakoglu, Live Science
A returning patch of warm water in the Northern Pacific Ocean called “the blob” could spell wonky weather for the U.S. this winter. Or, that’s what recent news reports suggest.
But as monstrous as its name sounds, “the blob” doesn’t really have a major impact on the atmosphere and the weather beyond a couple hundred miles inland of the West Coast, scientists at the National Oceanic and Atmospheric Administration (NOAA) told Live Science.
In 2015, the blob was blamed for a dry spell in the West and for prompting endless snow on the East Coast. But this is a questionable and “overly simple narrative,” said Mike Halpert, the deputy director of the Climate Prediction Center at NOAA.
Unlike El Niño — a climate cycle sparked by unusually warm water in the tropics that can have a major impact on the atmosphere and weather patterns — a blob of warm water that far up in the Northern Hemisphere has “fairly minimal” effects on the atmosphere, Halpert said. “In the tropics where El Niño is, the ocean drives the atmosphere, but up in the northern latitudes like the south of Alaska, the atmosphere drives the ocean,” Halpert said.
Where did the blob come from?
The current “blob” in the Northeast Pacific is a result of a mega-high-pressure zone that took shape in the atmosphere above it. This higher-than-normal pressureover the Gulf of Alaska, which most likely formed as a fluke, sprinkled Alaska with a mild and warm autumn, free of major storms. The absence of heavy winds and drops in temperature heated up the North Pacific waters.
It wasn’t the blob that created a high-pressure zone; it was the high-pressure zone that created the blob.
That being said, the blob itself can have some significant effects on the temperature along the West Coast, according to Nicholas Bond, the state climatologist for Washington and research scientist with the University of Washington and the Pacific Marine Environmental Laboratory at NOAA, who was the first to coin the term “blob.”
“Prevailing winds from California to southeast Alaska blow from west to east,” Bond said. In other words, they blow off the warm ocean onto land. In 2015, because of these winds, the coast was warmer than usual, he said. In June of that year, average monthly air temperatures were 1.8 to 10.8 degrees Fahrenheit (1 to 6 degrees Celsius) warmer than normal in the Western states.
But the effects can be felt for only a couple hundred miles inland, Bond said. Besides impacting nearby air temperatures, the “blob” doesn’t “seem to play a big role in terms of wind and pressure patterns themselves,” he said.