WSET.com - ABC13Developing La Nina by Matt Ferguson

When referring to weather, many of us have heard of El Nino and La Nina, but what does it really mean??? El Nino - is warmer than normal sea-surface temperatures in the central and eastern tropical Pacific Ocean that impact global weather patterns.

La Nina - is cooler than normal sea-surface temperatures in the central and eastern tropical Pacific Ocean that impact global weather patterns.

Both El Nino and La Nina affect our weather here in Virginia very differently. Of course, there are always many other factors that come into play as well. Others include: Madden Julian Oscillation, Arctic Oscillation, North Atlantic Oscillation, Pacific/North American Pattern, Antarctic Oscillation.

Right now we'll focus on El Nino and La Nina.

For late 2009 and early 2010 scientists have observed El Nino conditions in the Pacific. This caused there to be less hurricanes in the Atlantic Ocean last season. For one reason, El Nino usually causes strong upper level winds over the Ocean, which tends to tear tropical systems apart. Also for our state it brought normal to above normal precipitation. If you recall, last winter we had numerous Gulf Lows that brought us heavy rain or snow. El Nino usually causes a strong subtropical jet stream to develop bringing storms off the Pacific, across Mexico and the northern Gulf of Mexico then up through the southeast.

Right now La Nina is developing. Therefore, hurricane season is expected to be very active, since upper level winds across the Atlantic will be weaker. During a La Nina our weather is affected in an opposite way of El Nino. Look for drier conditions as we head into this upcoming fall and winter. As far as temperatures are concerned, usually the La Nina pattern brings above normal temperatures to the region. With all this said, I think it's probably a good bet that we will NOT see as much snow as last winter. However, you never know what Mother Nature will bring around the next corner.

PS: **NEWSFLASH** While over the last 1 to 2 years the average global temperature has been rising... Get ready for a full reversal! There are indications that the world is getting ready to go into a net cooling phase!!