Updated 08/21/17 ENSO Neutral through late Summer 2017 into the Winter 2017-18

Synopsis: ENSO-neutral is favored (~85% chance during Jul-Sep, decreasing to ~55% during Dec-Feb) through the Northern Hemisphere winter 2017-18. During July, ENSO-neutral continued, as equatorial sea surface temperatures (SSTs) were near average across most of the Pacific Ocean (Fig. 1). The latest weekly Niño SST index values were close to zero in all four Niño regions (Fig. 2), having recently decreased from higher levels in the Niño-4 and Niño-3.4 regions. The upper-ocean heat content anomaly was near average during July (Fig. 3), reflecting below-average temperatures along the thermocline across the central and eastern Pacific overlain by slightly above-average temperatures (Fig. 4). Tropical convection was near average over the eastern half of the Pacific and enhanced over the western Pacific and the Maritime Continent (Fig. 5). The lower-level trade winds were slightly enhanced near the International Date Line, and upper-level winds were near average over most of the tropical Pacific. Overall, the ocean and atmosphere system remains consistent with ENSO-neutral. The majority of models favor ENSO-neutral through the remainder of 2017 (Fig. 6). These predictions, along with the demise of the recent Pacific warmth and continued near-average atmospheric conditions over the Pacific, lead forecasters to favor ENSO-neutral through the winter. However, some chance for El Niño (15-20%) or La Niña (25-30%) remains during the winter. Also, ENSO-neutral conditions are predicted for the upcoming peak months (August-October) of the Atlantic hurricane season. In summary, ENSO-neutral is favored (~85% chance during Jul-Sep, decreasing to ~55% during Dec-Feb) through the Northern Hemisphere winter 2017-18 (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 14 September 2017. 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.



  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?


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: