SAN DIEGO (KGTV) - The Climate Prediction Center released the final El Niño advisory for 2019, which means El Niño is over and now we are in a neutral phase with a 55 percent chance of continuing into winter.
So what does that mean for the rest of summer and, most importantly, San Diego's winter? In order to put this in perspective, let’s review what this seasonal change means.
San Diegans typically associate El Niño with a wet winter, or more rain and a better water supply. However, El Niño is more than that.
The National Weather Service defines El Niño as a recurring climate pattern involving changes in the central and eastern tropical Pacific Ocean. Warm and cool changes are associated with the ENSO cycle. El Niño and La Niña are extreme phases of the ENSO cycle, but there is a third phase, less well known, called the ENSO neutral. That third phase is where San Diego is headed for the rest of the year and possibly through the winter months.
El Niño and La Niña have a greater impact during the winter months. La Niña doesn’t do much for winters in California; it typically keeps San Diego dry and warm. The opposite happens during El Niño, which explains why it’s so much more popular. El Niño brings an active Jet and more frequent storms, reducing our drought and helping our water supply, with cold driven storms and snow for the Sierra Nevada mountains.
The neutral phase is where San Diego is headed this fall with a 55 percent chance of it sticking around through the winter. The ENSO neutral phase is neither cold like La Niña nor warm like El Niño. The ENSO neutral phase is associated with sea surface temperatures closer to average, and stronger winds near the equator. It typically keeps the coldest air over the Northeast, warmer temperatures through the southern portion of the country, and wetter through the Midwest and Northeast.
The ENSO Neutral typically keeps San Diego warm and dry. The extended forecast calls for above-normal temperatures for the remainder of the summer and near normal rain, which means dry since we are usually dry during those months.
The winter outlook also brings near to slightly above normal temperatures. Rainfall will average near normal.
San Diego's rainy season begins in November and lasts through March, sometimes lasting through April.
Month | Average Rainfall
|
November | 1.01” |
December | 1.53” |
January | 1.98” |
February | 2.27” |
March | 1.81” |
April | 0.78” |
The average rainfall for the entire year in San Diego is 10.34 inches. During the months of November through April, we average more than 9 inches of rain. So, all we need is one storm every month during the winter time to keep us on track for the year.
While the forecast favors an ENSO Neutral phase, there is a 30 percent chance the seasonal outlook could retrend toward El Niño. If we go back to El Niño, there is a better chance any given storm that moves into Southern California will be a rain maker, even if we only have a few storms.
We will continue to monitor the changes; another year of surplus rain would be great for our region.
