NOAA (National Oceanic and Atmospheric Administration) just released an announcement heralding the arrival of an El Nino event. I think the name El Nino more often than not conjures up negative weather images in many peoples minds but not all of the impacts of this global weather pattern are bad. In the short term we may see a decrease in the Atlantic hurricane activity for the remainder of the Summer. This is caused primarily by an increase in stratospheric wind speeds over the tropical Atlantic where these seasonal storms breed. I suspect the seasonal hurricane forecasters are scrambling to update their foreacsts based on this new information. So far we have just seen one weak Tropical Depression form in the Atlantic hurricane arena.
Many of you may recall the tremendous rain and resultant mudslides along the west coast which were associated with the El Nino of 1982. While we may see more rain out west that can also supress the wildfire activity. Obviously another benefit.
Here in America's Heartland El Nino should have little if any effect on our warm season weather although a decrease in tropical activity could reduce the threat of flooding similar to what we had here last September from the remnants of "Ike". The most pronounced impact here in St. Louis may be a relatively dry and mild Winter. There are, of course, exceptions. The last El Nino was in 2006 a year which brought a significant early season Winter storm to St. Louis.
Here's a link to the NOAA Press Release.