National Weather Service backtracking some on El Nino forecast

Via NOAA: "After several months of intensification, warmer than normal sea surface temperatures in the Pacific, a sign of El Niño, have weakened. This image, taken from NOAA View, shows sea surface temperatures that are warmer or cooler than then 1981-2010 average, as measured by NOAA satellites. The “tongue” of red extending across the eastern equatorial Pacific is much smaller in July 2014 than in the comparable image from June 2014. "

Via NOAA: “After several months of intensification, warmer than normal sea surface temperatures in the Pacific, a sign of El Niño, have weakened. This image, taken from NOAA View, shows sea surface temperatures that are warmer or cooler than then 1981-2010 average, as measured by NOAA satellites. The “tongue” of red extending across the eastern equatorial Pacific is much smaller in July 2014 than in the comparable image from June 2014. “

Many meteorologists thought El Nino was a done deal this year, or close to it. Turns out, like an obstinate dog, the would-be El Nino has balked.

The National Weather Service today reduced the odds El Nino will develop by next winter from 80 percent to 65 percent.

“We’ve gone from an estimated 1-in-5 chance that we won’t have an El Nino to a nearly 1-in-3 chance,” notes the NWS El Nino blog.

The warming of tropical Pacific ocean waters required for El Nino to develop has actually reversed in the past month. And the atmospheric signal of El Nino has yet to emerge.

“As of the beginning of August, we still haven’t seen a strong atmospheric response … and the sea-surface temperature in the central-Eastern Pacific has cooled,” the El Nino blog says.

Although ocean temperatures  are headed in the wrong direction for an El Nino event, NWS climate analyst Michelle L’Heureux told Climate Central that of the seven El Ninos since 1990, a June to July ocean cooling event occurred in three instances – 1994, 2004 and 2006 — before warming resumed. “So there is precedent for this, I guess, sort of summertime lull,” L’Heureux said.

Despite recent inauspicious signs for El Nino prospects, the NWS still believes the balance of evidence favors its formation – at weak to moderate levels – into the fall. Models remain bullish El Nino remains in our future, from the NWS CFS version 2 model to its National Multi-Model Ensemble (NMME).

“All of the (NMME) models are still calling for El Niño conditions to develop,” the El Nino blog says.

July North American Multi-Model Ensemble (NMME) ensemble forecast for Nino3.4 sea-surface temperature. (NWS CPC)

July North American Multi-Model Ensemble (NMME) ensemble forecast for Nino3.4 sea-surface temperature. (NWS CPC)

Several of the models forecasting El Nino correctly captured the recent ocean cooling, increasing confidence in their future outlooks.

The El Nino blog reminds us that NWS’ assessment that El Nino has a 65 percent likelihood is almost twice the climatological “norm”. But is also notes that there’s a one in three chance models will be wrong, just like two years ago when forecasts for El Nino fell apart.

An El Nino event, if it occurs and depending on its strength, could help relieve the California drought while favoring a snowy winter in the Mid-Atlantic. While not completely formed as of the moment, it is thought to already be increasing Pacific hurricane activity and decreasing Atlantic hurricane activity in its fledgling state.

Related: El Niño plays coy with forecasters in 2014 | Edging closer to El Niño: 70 percent chance of development this summer | Which parts of U.S. could benefit most from El Niño? | El Niño odds rise to 80 percent by winter; beware of forecasts of doom | Bet on El Niño, says NOAA | A super El Niño on the way? Subtle signs emerging | Mid-Atlantic may enjoy cool summer if El Niño develops | El Niño watch posted: May portend fewer Atlantic hurricanes and beneficial California rains

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