DULUTH - Climate experts for the National Oceanic and Atmospheric Administration on Thursday bumped the chances of a strong El Niño to 95 percent, up from 90 percent, signaling a better chance for a warmer winter across the Upper Midwest.
The current El Niño warming of Pacific Ocean waters is approaching the strength of the strongest on record, 1997-98, and should persist through the winter, said Mike Halpert, deputy director of NOAA’s Climate Prediction Center.
But Halpert said he’s not yet convinced the current El Niño will be stronger than ‘97-’98.
“We don’t throw a 95 per-
cent chance out very often,” Halpert told a national media teleconference Thursday. “The question is how strong it stays through the winter.”
The relative strength of the current El Niño should make its effects even more noticeable - spreading rain and floods to drought-parched California, weakening Atlantic hurricanes and bringing warmer conditions to the Upper Midwest.
Halpert said he’s already seen an impact with weaker Atlantic storms in recent weeks.
Climate experts say there are historical records showing strong El Niño winters mean warmer temperatures across the northern Great Plains and into the Great Lakes. That’s already showing up in the NOAA long-range forecast for December-February which shows a very strong chance of a warmer-than-normal winter for all of northern Minnesota, with a bull’s-eye on Duluth.
The 1997-98 El Niño brought Duluth a winter that ended up a whopping 9.5 degrees above average, according to National Weather Service data. That included a high of 35 on New Year’s Day and 37 on Jan. 2. There were only six days all winter with any below-zero temperatures.
International Falls was even farther above normal during the winter of 1997-98, at 11.7 degrees above average.
An El Niño winter doesn’t mean it can’t get cold -- it did hit 20 below zero one January morning in 1998 in Duluth. And it’s not a guaranteed connection. In 2009-10, a moderate El Niño year, Duluth ended meteorological winter with near-normal temperatures. But, on average, the majority of strong El Niño winter days see temperatures well above normal.
Precipitation for the region seems less impacted, but snowfall is generally down some.
Snowfall during the 1997-98 winter was just 4 inches below normal for Duluth, although the 1957-58 El Niño winter saw less than half the normal 50 inches from December through February.
El Niño events officially are marked by a 1.5 degree Celsius or greater temperature rise in the equatorial Pacific Ocean, which causes a stalling of trade winds and a shifting of a subtropical jet stream. This year, the water may top 2 degrees warmer than usual, and already has topped that in some areas.
During the past two months the current El Nino has “continued to warm and is continuing to evolve,” Halpert said.
El Niños can wreak havoc in areas where they bring heavy rain and floods or enhanced winter storms. But they also can be a godsend to Midwesterners’ pocketbooks thanks to lower heating bills. A 1999 study published in the Bulletin of the American Meteorological Society estimated that while the 1997-98 El Niño caused $4 billion in damage, it brought with it $19 billion of economic relief: lower heating bills and less damage from hurricanes.
Strong El Niños hit in 1997-98, 1982-83 and 1972-73. There were moderate El Niños in 2009-10, 2002-03 and 1991-92.
