Although the fall colors have begun in the Mount Hood region, winter is
already predicted to arrive later and to be warmer and drier then the past two
years.

The National Oceanic and Atmospheric Administration (NOAA) winter weather
outlook for 2018-19 predicts a 70 percent chance of El Niño conditions
developing this winter, resulting in higher-than-average temperatures with
lower-than-average precipitation in the Pacific Northwest. The scientists at
NOAA use global weather patterns as well as the development of El Niño or La
Niña conditions to make their seasonal forecasts.

“It’s kind of (looks like) what we expect with an El Niño winter, a mild winter,”
said David Bright, meteorologist with the National Weather Service in
Portland.

El Niño and La Niña are opposite phases of the El Niño-Southern Oscillation
(ENSO) cycle. The ENSO cycle is a scientific study of the temperature
fluctuations between atmospheric and ocean temperatures in the central
Pacific.

Of these two phases, La Niña is considered to be the cold phase of the ENSO
cycle, and El Niño is considered to be the warmer phase.

Bright stated that tropical water temperatures are currently a degree higher in
the central Pacific, which is in the weak to moderate range for El Niño
conditions.

In the Pacific Northwest there is a 50 to 55 percent El Niño prediction from
September through December, with above-average temperatures and below-
average precipitation.

This suggests the possibility of a slow start to winter conditions in the
Northwest with drier conditions in the fall.

In mid to late winter, January through March there is a 70 percent El Niño
prediction with above-average temperatures predicted and equal-to-average
chances of precipitation after the new year.

“Precipitation signals are weaker with El Niño conditions,” Bright said. He
added it was hard to predict if the condition would impact the amount of
precipitation on the mountain, but that the winter would be milder overall.
“Let’s hope we fill the reservoirs and get some snow on the ground for
recreation.”

“Both 2016-17 and 2017-18 were La Niña, which tends to be a cooler, wetter
winter,” Bright added. “We’re looking at a milder winter.”

As recently as 2017-18 the Northwest received higher levels of precipitation
then the initial NOAA forecast.

Current information about the ENSO El Niño Watch can be found online at
https://www.climate.gov/enso.