1.   Is it affecting the weather all round the world?

2.   All agree that we are now in an extended La Nina, an event that occurs in the equatorial Pacific but affects weather in both hemispheres.

3.   But lately, in an effort to understand better how broad changes in climate might affect day-to-day weather, experts have begun to scrutinize the patterns more closely.

4.   Climatologists are blaming the trend on La Nina, a cooling of Pacific waters off the coast of South American that affects global weather.

5.   El Nino occurs when trade winds slow in tropical regions of the Pacific Ocean, warming water temperatures off the coast of Peru and affecting weather around the world.

6.   El Nino occurs when trade winds slow in tropical regions of the Pacific Ocean, warming ocean temperatures off the coast of Peru and affecting weather around the world.

7.   For that matter, nobody knows exactly how the huge patch of warm Pacific water manages to affect weather around the world.

8.   How is it measured, and how does it affect the weather?

9.   Should El Nino develop as predicted next winter, it could affect the weather in the United States in a variety of ways.

10.   Some seemingly far-fetched explanations have even included global warming and El Nino, an occasional warm ocean current that can affect the weather, Sakai said.