EL NIÑO/SOUTHERN OSCILLATION (ENSO) Discussion

[Gman]

issued by
CLIMATE PREDICTION CENTER/NCEP
6 March 2008


Spanish Version


Synopsis: La Niña is expected to continue through the Northern Hemisphere spring 2008.

Atmospheric and oceanic conditions during February 2008 continued to reflect a strong La Niña. Equatorial SSTs were more than 2.0°C below average across large portions of the central and east-central equatorial Pacific (Fig. 1), and the corresponding weekly values of the Niño-4 and Niño-3.4 indices remained between -1.6°C and -2.1°C during the month (Fig. 2). In contrast, SSTs in the far eastern equatorial Pacific were above average during February 2008, in association with a warming trend that began in mid-December. The upper-ocean heat content (average temperatures in the upper 300m of the oceans between 180° - 100°W) remained below average across the equatorial Pacific during February (Fig. 3), with the largest temperature anomalies averaging -2°C to -6°C at thermocline depth (Fig. 4). Consistent with these oceanic conditions, stronger-than-average low-level easterly winds and upper-level westerly winds persisted across the central equatorial Pacific, convection remained suppressed throughout the central equatorial Pacific, and enhanced convection covered the far western Pacific. Collectively, these oceanic and atmospheric conditions are similar to those accompanying the last strong La Niña episode in 1998-2000.

The most recent dynamical and statistical SST forecasts for the Niño 3.4 region continue to indicate a moderate-to-strong La Niña through March 2008, and a weaker La Niña through April-May-June 2008 (Fig. 5). Thereafter, there is considerable spread in the forecasts, with approximately one-half indicating that La Niña could continue into the Northern Hemisphere fall. Current atmospheric and oceanic conditions and recent observed trends support the likely continuation of La Niña through the Northern Hemisphere spring 2008.

Expected La Niña impacts during March-May 2008 include a continuation of above-average precipitation over Indonesia and below-average precipitation over the central equatorial Pacific. The above average SSTs in the eastern equatorial Pacific may result in increased rainfall over Ecuador and northern Peru, similar to the evolution during the 1998-2000 La Niña episode. Compared to the Northern Hemisphere winter, La Niña impacts over the United States in spring are typically less pronounced. The primary springtime signal for the contiguous United States is an increased probability of below-average precipitation across the South, particularly in the Southeast.

This discussion is a consolidated effort of the National Atmospheric and Oceanic 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 for the evolution of El Niño/La Niña are updated monthly in the Forecast Forum section of CPC's Climate Diagnostics Bulletin. The next ENSO Diagnostics Discussion is scheduled for 10 April 2008. To receive an e-mail notification when the monthly ENSO Diagnostic Discussions are released, please send an e-mail message to: [e-mail].

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.html

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Even shorter synopsis: It's going to stay dry in the US Southeast and the La Nina continues through the spring.

[panader0]

1. La nina makes it dry here too.

Where is the tilde on the keyboard?

[Gman]

2. You hold down the Alt key, then with the number keypad type 165

for a capital Ñ or alt + 164 for a lower case ñ. You must use the number pad rather than the regular numbers on the keyboard for this to work.

Didn't think you'd learn this in the environment/energy forum, huh?!

[phantom power]

3. is there somewhere these are documented?

[Gman]

5. Look here

http://www.spanishnewyork.com/spanish-characters.html

[Tashca]

4. Midwest climatologist

Elwyn Taylor is like a weather god here in the corn belt. He is retired but still puts on meetings for Iowa State University when he has time. I had the opportunity to listen to him in mid-February. Of course he will not make a direct prediction like any good climatologist....but pointed out trends.

He talked about La Niña and here is his statement:"If La Nina lasts into August, there is a 70 percent chance of a below trend line yield of 142 bushels per acre on corn, and a 34 percent greater risk of drought," Taylor said.

Now this isn't the part that has been haunting me...

I'm trying to remember what all he said.
He went on....he talked about the 21 year drought cycle here in the corn belt....based on over 800 years history. (I think I have that right)... The last major drought was 1988. We are entering our 19th year in this cycle. He claims the cycle has never ever gone over 23 years. I realize that certainly doesn't mean a drought here this year.....but it's coming....and with all the weather related crop shortages happening around the world
Well you get what I mean I'm sure..

[Dogmudgeon]

6. How do you think this will affect Tornado Season?

There seems to be a very strong flow of tropical air across the eastern quarter of North America. While it has suppressed snow, the same effect should produce a strong climate for spring thunderstorms. But these ENSO-related weather regimes are difficult to divine. Any thoughts?

--p!