What Is El Nino and La Nina?

YouNewsTV™

Story Published: Oct 4, 2006 at 1:49 PM PDT

Story Updated: Oct 4, 2006 at 1:49 PM PDT

By Scott Sistek

They are large-scale patterns that result from changes in ocean temperatures in the equatorial Pacific Ocean region.

El Nino is caused when the temperatures are warmer than normal. La Nina is when they're cooler than normal.

Scientists are still trying to find out what causes these phenomenon and their apparent effects on the climate around the world.

However, during El Nino events, the winters around the Pacific Northwest tend to be warmer and drier than normal, as the jet stream tends to point further south into central and southern California.

La Nina events tend to lead to cooler and wetter-than-normal, as the jet stream tends to park over the Pacific Northwest.

"Neutral years" -- winters where there's neither of those two events going on -- tend to be more variable, as the jet stream tends to move around more often. So we could have a stretch where it's warm and dry, followed by a stretch of cold and snowy. In essence, all bets are off, and we're open to anything.

Neither of the events appear to have much of an effect on summer weather, but there's still plenty of research going on in the field.

For More Information:

El Nino Information -- www.cdc.noaa.gov
La Nina Information -- www.pmel.noaa.gov

This content requires the latest Adobe Flash Player and a browser with JavaScript enabled. Click here for a free download of the latest Adobe Flash Player.

KOMO Weather

Current Temp 60 °F

Partly Cloudy

Wind : From the South at 5 MPH

Humidity : 78 %

Pressure : 30.07" (1018.7 mb)

More Weather

Traffic

Traffic Alert

North Cascades Highway (S.R. 20) is closed due to high avalanche danger through the weekend. Crews will return on Monday to assess road conditions. The state DOT advises drivers to check mountain pass conditions for all passes before leaving this weekend.

More Traffic