Updated 03/08/18 – La Nina transition to Enso Neutral in the Spring and Summer 2018

Synopsis: A transition from La Niña to ENSO-neutral is most likely (~55% chance) during the March-May season, with neutral conditions likely to continue into the second half of the year. During February 2018, La Niña weakened, but was still reflected by below-average sea surface temperatures (SSTs) in the east-central equatorial Pacific Ocean (Fig. 1). The latest weekly index values were -0.8C and -0.6C in the Niño-3.4 and Niño-3 regions, respectively, and were near zero in the surrounding Niño.4 and Niño1+2 regions (Fig. 2). While negative anomalies were maintained near the surface, the sub-surface temperature anomalies (averaged across 180°-100°W) warmed to near zero (Fig. 3). This warming was due to the eastward propagation of above-average temperatures along the thermocline in association with a downwelling equatorial oceanic Kelvin wave (Fig. 4). The atmospheric anomalies typical of La Niña weakened considerably across the tropical Pacific. Convection was suppressed near Indonesia and was only weakly enhanced over the far western Pacific (Fig. 5). Also, low-level wind anomalies were westerly over the western and central Pacific, while upper-level winds remained anomalously westerly over the eastern Pacific. Overall, the ocean and atmosphere system suggests La Niña is weakening. Most models in the IRI/CPC plume predict La Niña will decay and return to ENSO-neutral during the Northern Hemisphere spring 2018 (Fig. 6). The forecast consensus similarly favors a transition during the spring, with a continuation of ENSO-neutral conditions through the summer. In summary, a transition from La Niña to ENSO-neutral is most likely (~55% chance) during the March-May season, with neutral conditions likely to continue into the second half of the year (click CPC/IRI consensus forecast for the chance of each outcome for each 3-month period). This discussion is a consolidated effort of the National Oceanic and Atmospheric Administration (NOAA), NOAA’s National Weather Service, and their funded institutions. Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center web site (El Niño/La Niña Current Conditions and Expert Discussions). Forecasts are also updated monthly in the Forecast Forum of CPC’s Climate Diagnostics Bulletin. Additional perspectives and analysis are also available in an ENSO blog. The next ENSO Diagnostics Discussion is scheduled for 12 April 2018. To receive an e-mail notification when the monthly ENSO Diagnostic Discussions are released, please send an e-mail message to: ncep.list.enso-update@noaa.gov. Climate Prediction Center National Centers for Environmental Predict



  1. Hope you enjoyed the rain……1-2 inches in S. California and more in Ventura.


  2. Pretty soon it will be there and quite a bit I think… 4-8 inches of rain or more in the lowlands with much higher amounts in the orographically favored locations. Perhaps over 20 inches in some mountain areas. Should be a very dangerous storm to some canyon locations as well as coastal areas where the high tides, wind, and flooding makes a high impact.

  3. Thanks very much….I appreciate your interest….I will try to keep you informed of extended Sierra weather in my summary.

  4. Great site! My daughter’s class is studying weather. Her teacher wrote: ” I was wondering if there are any meteorologists out there or just huge weather buffs who would like to come do a presentation to the sixth graders about air and water currents, in particular El Nino years. We’ve been studying it in class but I am not a specialist in this area and would love to have someone with more knowledge explain the factors that influence weather.” I wondered if this us up your alley at all? Let me know if so, and I’ll find out more particulars. Thanks a lot. –Teal

    • Teal,

      Sure I have done this for my kids and several classes at Children’s Health Council where I worked for over 14 years….I would need an internet connection that could be projected onto a screen from my laptop so that I could use visuals and they could see first hand how weather forecasts are done and the forces that causes weather changes……

      What school and what are the ages of the students?

      Richard Stolee

      • Thank you! The kids will love it. These are 6th graders at JLS in Palo Alto. What’s the best way to contact you to work out date/time etc?


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