Climate Prediction Center: El Niño Watch (70% chance during winter 2018-19) #ENSO

Here’s the diagnostic discussion from the Climate Prediction Center:

ENSO Alert System Status: El Niño Watch

Synopsis: ENSO-neutral is favored through Northern Hemisphere summer 2018, with the chance
for El Niño increasing to about 65% during fall, and to about 70% during winter 2018-19.

ENSO-neutral continued during June, as indicated by slightly above-average sea surface temperatures (SSTs) across the central and eastern equatorial Pacific. The latest weekly Niño indices were between +0.3°C and +0.6°C, except for the Niño-1+2 index, which was -0.2°C. Positive subsurface temperature anomalies (averaged across 180°-100°W) continued over the past month, and the volume of anomalous warmth now extends to the surface in the eastern part of the basin. Convection remained suppressed near the Date Line and was near-average over Indonesia. Low-level wind anomalies were near average across the equatorial Pacific Ocean, except in the east- central Pacific, where anomalies were westerly. At upper-levels, winds were easterly over the east-central Pacific and near the International Date Line. Overall, the oceanic and atmospheric conditions reflected ENSO-neutral.

The majority of models in the IRI/CPC plume predict ENSO-neutral to continue through the Northern Hemisphere summer 2018, with El Niño most likely thereafter. The forecaster consensus favors the onset of El Niño during the Northern Hemisphere fall, which would then continue through winter. These forecasts are supported by the anomalous subsurface warmth across the eastern half of the tropical Pacific Ocean. In summary, ENSO-neutral is favored through Northern Hemisphere summer 2018, with the chance for El Niño increasing to about 65% during fall, and to about 70% during winter 2018-19 (click CPC/IRI consensus forecast for the chance of each outcome for each 3-month period).

From The Durango Herald (Jonathan Romeo) via The Cortez Journal:

Southwest Colorado may escape the arid grip of the La Niña weather pattern, with forecasters saying there’s a good chance El Niño, and the moisture it brings, will return this fall.

One of the major dictators of weather in Southwest Colorado is surface water temperatures in the eastern-central Pacific Ocean that come in cycles known as the “El Niño-Southern Oscillation climate pattern.”

When surface water temperatures in the ocean are colder than normal, a La Niña pattern kicks in. La Niñas typically bring above-average temperatures and little, if any, precipitation to Southwest Colorado.

This past year has been a classic La Niña pattern, with little snowpack and virtually no precipitation, resulting in one of the driest years in Southwest Colorado’s recorded history.

Since April, the region has been listed in “exceptional drought” – the most intense drought category, according to the U.S. Drought Monitor. As of Tuesday, the region still holds this listing.

However, the National Oceanic and Atmospheric Administration’s Climate Prediction Center released some good news recently: El Niño, which holds the promise for more moisture, could be on its way.

The opposite of La Niña, an El Niño, which often brings Southwest Colorado winters with plentiful snowfall, occurs when surface water temperatures in the Pacific Ocean are warmer than normal, which results in a better chance for precipitation.

Michelle L’Heureux, a climate scientist for NOAA’s Climate Prediction Center, said Southwest Colorado has been in a “neutral” weather pattern since the effects of La Niña subsided a few months ago.

This map of a typical El Nino weather pattern shows Colorado right on the edge of moisture impacts. (Courtesy: National Weather Service)


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