Previous trends in the tropical Pacific favored a weak El Niño event this winter. Weak El Niño events (+0.5C) exert less predictable influence on wintertime upper air patterns in the northern hemisphere than moderate (+1.0C) or strong (+1.5C) El Nino events.
“We find ourselves on the verge of El Niño this year, with the equatorial Pacific ocean recently warming to levels close to the minimum threshold,” said Mike Halpert, deputy director of NOAA’s Climate Prediction Center, in a telephone briefing with reporters on Thursday. “There’s currently an El Niño Watch in place with a 70 to 75 percent chance that El Niño will develop during the next few months.”
Milder, wetter than normal winter on tap for NM
Here’s the typical average wintertime upper air pattern over North America in a moderate or strong El Niño event.
Wet and mild: Warm winter predicted for much of the US
The latest October ensemble average from the suite of ENSO models calls for a slightly stronger #ElNino event than was predicted in September. New ensemble average calls for borderline weak/moderate event peaking around 1°C in December-February. pic.twitter.com/hWLHYMXOUf
ALBUQUERQUE, N.M. — A weak El Niño weather pattern could bring milder and wetter than average conditions to New Mexico this winter, according to the NOAA Climate Prediction Center’s winter outlook for December through February.
This winter’s El Niño event may be showing signs of evolving into a so-called “El Niño Modoki” event.
Most El Niño events feature warmer than average ocean water in the eastern Pacific off the coast of South America. But El Niño Modoki events feature warm water in the central Pacific, bracketed by colder water to the east and west.
El Niño Modoki is a coupled ocean-atmosphere phenomenon in the tropical Pacific. It is different from another coupled phenomenon in the tropical Pacific namely, El Niño. Conventional El Niño is characterized by strong anomalous warming in the eastern equatorial Pacific (see figure above). Whereas, El Niño Modoki is associated with strong anomalous warming in the central tropical Pacific and cooling in the eastern and western tropical Pacific (see figure above). Associated with this distinct warming and cooling patterns the teleconnections are very different from teleconnection patterns of the conventional El Niño. Hence, the new phenomenon is of interest to the climate community.
Jet stream pattern during an El Niño Modoki winters may vary from typical El Niño winters. That can impact temperature trends across North America.
There are two strong reasons to predict a milder than average winter this year. The likelihood (70% to 75%) of an El Niño event this winter is one. The longer-term trend of a strong winter warming signal in Minnesota is another. So the climatological forcing mechanisms favor a milder than average winter this year.
But confidence is lower than in most El Niño winters. The El Niño Modoki may throw jet stream patterns into disarray. That leaves open the possibility of more frequent polar outbreaks.
Halpert said the southern one-third of the United States and much of the East Coast could be hunkering down for a wetter than normal December through January. The chances are highest in southeastern Georgia and much of northern and central Florida.
Paul Huttner is chief meteorologist for Minnesota Public Radio. Huttner has worked TV and radio stations in Minneapolis, Tucson and Chicago. Paul is a graduate of Macalester College in St. Paul and holds a bachelor’s degree in geography with an emphasis in meteorology.
There are signs that El Niño, a climate phenomenon characterized by a warming of waters in the eastern tropical Pacific, is imminent according to an update released on Thursday by the International Research Institute for Climate and Society (IRI). It will arrive just in time for winter to rearrange the worlds weather, including ushering in a warmer-than-normal winter for much of the U.S.
The latest update on El Niño that included input from human researchers at IRI and the National Oceanic and Atmospheric Administration (NOAA) was released on Oct. 11. It gave strong odds that El Niño would form in the next month or so. The update released on Thursday uses models only, and finds the odds to be even higher. It puts the chances well see an El Niño from winter until early spring of 2019 at an 85-90 percent.
The conditions in and above the Pacific seem to agree. NOAA defines El Niño as when ocean temperatures in a region of the eastern tropical Pacific (dubbed NINO3.4 in climate nerd talk) are 0.5 degrees Celsius (0.9 degrees Fahrenheit) above normal for three months in a row. That region is currently just over that threshold, and a big pulse of warm water below the surface thats working its way across the Pacific should help El Niño conditions blossom. Its not likely to be a blockbuster El Niño, but it should still have enough of an impact as it propagates through the atmosphere to affect weather patterns elsewhere.
And as it so happens, the El Niño update on Thursday coincided with NOAAs winter weather outlook. Meteorologists know how El Niño can tip the odds one way or the other for certain types of weather, so the outlook is pretty confident in showing higher odds of warmth across much of the U.S. save the Southeast. The outlook also shows wet weather for the southern tier of the country, while the Northern Rockies are likely to be drier than normal. The wet weather in the Southwest would certainly be a relief, since the region is in the grips of an intense drought.
El Niño is far from the only natural climate shift to affect weather. Youve got your Arctic Oscillation and your Madden-Julian Oscillation (to say nothing of the unnatural shift driven by human-caused climate change). And a forecast for, say, increased odds of a warmer-than-normal winter in Spokane does not mean there will be no cold spells. Sometimes winter just has to winter.
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