The Return of La Niña???!!!

August 15, 2011

PrintPrintEmailEmail
Your rating: None Average: 2.9 of 5 (14 votes)

La Niña might return. The huge Pacific weather event that shaped last winter and this year’s miserable spring may come back.

SAY IT ISN’T SO! This could mean another frozen winter, continued drought in Texas and even a possibility of floods in the Midwest next spring. How likely is it? Should we be getting out the long winter underwear?

First—let’s do the world’s quickest review. A La Niña (Spanish for “little girl”) is the world’s strangest name for rotten weather. It is a huge pool of cool water in the tropical Pacific. The water cools the air above it – which changes air pressure—which changes wind patterns—which changes weather. Since the La Niña is huge, its impact affects global weather, including conditions in the US. (This combination of ocean and weather conditions is frequently abbreviated as ENSO).

This week the National Oceanic and Atmospheric Administration (NOAA), the agency that monitors weather, climate and ocean conditions, wrote: ENSO-neutral is expected to continue into the Northern Hemisphere fall 2011, with ENSO-neutral or La Niña equally likely thereafter. (Translation: Expect a normal fall and maybe winter will be normal and maybe it will be miserably cold.)

Yet the agency’s Climate Forecast System’s models writes: The CFS . . . predicts La Nina conditions to develop during the Northern Hemisphere fall 2011. (Translation: The La Niña and the crummy weather it brings will hit this fall and winter.)
CFS Forecast
The average of the US Climate Forecast System models predict the tropical Pacific will drop over 1°C (1.8°F) below normal, creating a cold La Niña. Source: NOAA

Huh? Which is it—normal weather or a cold La Niña?

Here’s what’s going on: Different nations are trying to predict whether La Niña will come back and they disagree. The US models almost all predict a cooler tropical Pacific. (See graph A) However the Korean models expect a mild warm El Niño. The French predict a neutral Pacific. Some of the Japanese models agree with the US that there will be a cool La Niña. It’s kind of a mess. When you average everything, all of the warm and cool models, the result is somewhere in the middle.
ENSO Model Predictions
Climate models from all over the world differ on whether or not there will be another La Niña and the average result is that the Pacific will remain normal. Source: NOAA

NOAA’s official pronouncement, is hedging between the global and its own CFS models. Unfortunately, the CFS has had a fairly good record for being right. So hope the global models are right and we have normal weather. Meanwhile, polish your skis in case snowy La Niña comes back!

Related Articles


Evelyn Browning Garriss, historical climatologist, blogger, writer for The Old Farmer's Almanac, and editor of The Browning Newsletter, has advised farmers, businesses, and investors worldwide on upcoming climate events and their economic and social impact for the past 21 years.

Comments

spring planting

By Larrymcf

I don't know about Texas, but we didn't have planting weather this year until late June in Central Oregon High Desert

Texas Weather

By Katherine Lewis

didn't the almanac predict a wetter than usual 2011 spring/summer for texas?

Record breaking USA winter 2011-2012

By MorElectricHeating

Nice post. Looks like a record breaking USA winter 2011-2012. Extreme cold & Snowmageddon levels of snow in the Northwest and Eastern USA especially.

And we are also saying huh at their ENSO forecast. We looked at the charts again today at

http://wattsupwiththat.com/reference-pages/enso/

and at

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

and if the Nina threshold is -0.5, then we are almost back to Nina RIGHT NOW, not in fall or winter!

Post new comment

Before posting, please review all comments. Due to the volume of questions, Almanac editors can respond only occasionally, as time allows. We also welcome tips from our wonderful Almanac community!

The content of this field is kept private and will not be shown publicly.
By submitting this form, you accept the Mollom privacy policy.