The American Geophysical Union is reporting that a large ‘blob’ of warm water off the West Coast of North America is responsible for much of the continent’s recently odd weather. The patch of water is two to seven degrees Fahrenheit above normal and could be a harbinger of more significant, global changes.

Some of the irregularities that could be caused by the phenomenon include the West Coast having recently been warmer and drier than unsual, the East Coast having been cold and blanketed in snow, fish migrating into new waters and seals on California beaches washing up hungry.

The anomaly began in 2013 – 2014 in the Gulf of Alaska but, to the surprise of scientists, has continued not only to exist but to expand. An oceanographer at Newport, Oregon’s Northwest Fisheries Science Center described the unusual nature of the warm area as “totally new.” But Bill Peterson went beyond the simple ‘blob’ description, characterizing the current temperature of the Pacific Ocean, from the West Coast to Japan, as “super warm.”

Exotic ocean species have been appearing in unexpected places, such as sunfish off the coast of Alaska. Also unusual there have been sightings of the tropical skipjack tuna.

The 2013-2014 “blob” was just the beginning. That summer, warm water also arrived off the California coast. Nate Mantua, a landscape ecology team leader with La Jolla, California’s Southwest Fisheries Science Center, said the ever-expanding heat blob – which is a consolidation of multiple such anomalies – may have global consequences. Rather than being just a large, unexplainable bubble, Mantua said it “looks like just an extreme shift into the warm state of the PDO.”

That’s the Pacific Decadal Oscillation, a strong, normally expected pattern of ocean and climate variability in a large region of the middle latitude areas of the Pacific Ocean. A change in this pattern, as suggested by Mantua, could be an indicator that Earth’s climate is on the edge of becoming warmer.