Pacific Ocean 'blob' hints at warm winter ahead for Alaska
The “blob,” as it’s called, is a huge area of warmer-than-normal water in the Pacific Ocean that extends from the coast of California to Alaska. The sea surface temperatures are some 2-3 degrees Fahrenheit above normal.
The blob formed during the winter of 2013/2014 when a large, persistent area of high pressure formed off the west coast of the Lower 48 and into the Gulf of Alaska.
Warmer temperatures formed beneath the ridge and there was little wind, due to the persistence of the ridge, which only strengthens the pattern.
“There is a bit of positive feedback that when we tend to have the ridge, we have warmer temperatures and when we have warmer temperatures, we tend to have the ridge so it does kind of tend to support itself,” says Bill Ludwig, a Senior Forecaster at the Anchorage National Weather Service Office.
For Alaska, warm sea surface temperatures in the Gulf of Alaska and the Bering Sea mean we'll likely continue with warmer-than-normal temperatures, particularly for southern coastal area.
The moderate-to-strong El Nino we're currently experiencing is expected to erode portions of the blob, particularly near the coasts of California and Mexico.
For Alaska, the El Nino years typically mean warmer sea surface temperatures, so the current El Nino won’t help the situation.
“Over the Northeast Pacific say from Washington and Oregon north into the Gulf of Alaska that warmth is not just at the surface, the anomalous heat content actually extends to some significant depth below the surface and that means it's going to take quite a while to change that,” said NWS Climate Scientist Rick Thoman.