El Niño no longer the prohibitive favorite for this winter

Seattle basks in some morning sunlight as seen from Kerry Park (KOMO Photo)

Just when we thought we were heading back to another El Niño winter this year, computer forecast models are starting to pump the brakes.

The latest analysis from the long range forecast models are backing off what was increasing confidence that we were doomed/blessed to experience another El Niño winter -- usually marked by generally mild conditions with lesser frequency of storms and greater difficulty getting lowland snow average mountain snow packs.

Late in April, the models were up to about a 65-69 percent chance of us having an El Niño winter, with about a 28 percent chance of neutral conditions (and just minimal chance of La Niña.)

Early and mid spring is a tough time to gauge the likelihood of El Nino/La Nina (called the "spring barrier") because the ocean is usually in a transition period. But now we're starting to get beyond the barrier and with new data in, the odds have now pushed back to where the odds of El Niño and a neutral winter are about even-steven - each in the mid-upper 40 percent range (with still a fractional chance of La Niña.)

Forecasters say the newest calculations suggest while the critical area of the central Pacific Ocean where temperatures are measured for El Niño will likely reach, then hover around the +0.5 Celsius warming anomaly to get El Niño status, the warmth "may not last long enough to qualify as an El Niño episode" (which requires 5 months in a row at +0.5C or more) and may not be strong enough to impact the atmospheric circulations that would trigger typical El Niño conditions.

"Relative to last month, the forecaster consensus reflects slightly lower chances of El Niño (~45%), in part due to the conflicting model guidance and lack of a clear shift toward El Niño in the observational data," NOAA said.

In other words, while our last El Niño was given a "Godzilla" nickname and was among the strongest on record, this El Niño may end up being about as weak as it gets to still claim the title.

If ocean conditions don't quite reach +0.5C then it will be considered a "neutral" winter. Historically speaking, neutral winters run the gamut with warm periods, cold periods, extended calm periods and extended stormy periods. Most of the region's greatest wind storms and flooding events have happened in neutral years (while snow tends to be more toward La Niña, but do happen in neutral years too.)

So skiers and cooler winter fans can have some hope that the odds of a mild winter just dropped a bit. But if I'm, say, a state climatologist, I'm probably not going to promise to eat a bug if we don't get a cold snap this winter.