What exactly does La Nina mean, you may be asking? It essentially is a cooling of Sea Surface Temperatures (SST) in the central and eastern portions of the tropical Pacific Ocean. The set up has warmer than average SST's over the western Pacific and cooler than average SST's in the central and eastern Pacific. La Nina typically occurs ever 3-5 years but consecutive episodes occur nearly 50% of the time, according to the NOAA Climate Prediction Center. While La Nina stems from the anomalies of SST's, its impacts go way beyond ocean temperatures.
|Sea Surface Temperatures showing a cooler eastern Pacific which signals a La Nina return. Via NOAA CPC.|
What can we expect for winter 2011? Average La Nina winters cause wetter than normal conditions here in the Pacific Northwest and can often expect cooler than average temperatures, too. La Nina doesn't offer much drought relief during the winter months either for those in the South and Southwest,
“This means drought is likely to continue in the drought-stricken states of Texas, Oklahoma and New Mexico,” said Mike Halpert, deputy director of the Climate Prediction Center.
|Typical La Nina setup|
With La Nina's anticipated return, records could fall again this winter. That would not be welcome news to most.