The National Oceanic and Atmospheric Administration has made it official: Another El Nino has begun, with sea surface temperatures in the eastern and central tropical Pacific Ocean now more than 1 degree Celsius above the average.

Red and orange colors on the map at left show where sea surface temperatures in the Pacific are 1 to 2 degrees above average.

The phenomenon, which occurs every two to five years, on average, typically triggers changes in weather trends around the globe. It is expected to last at least a year, and is the first El Nino since 2006. Here's more from NOAA.

For Maryland, El Nino's effects are not as cut and dried as they are for some parts of the world, such as the Pacific coast and Indonesia. But studies have found a trend toward stormier winters. That can mean a lot of snow, or very little - a sort of all-or-nothing deal, depending on temperatures. The most notable storm in an El Nino year may have been the Feb. 11, 1983 storm that dropped 22.8 inches on Baltimore (photo, right).

The general conclusion the experts have reached about El Nino Winters in Baltimore is summed up this way:

"El Niño winters in the Baltimore Region mean a milder than normal December. They also tend to be all or nothing when it comes to snowfall. Either there are no significant snow storms and season snow totals average less than 5 inches or there is a tendency toward multiple snow storms with seasonal totals above 30 inches.  These storms usually occur in January and February. November, December, and March often see little or no snow."

You can read more about this here.

(SUN PHOTO by Weyman Swagger 1983)