Shift in Pacific Ocean Temp Offers Weather Predictability during Winter Months

Earlier in the spring, a strong El Nino was predicted in the equatorial Pacific, which would bring drought relief to much of the south and west.  Now, scientists are saying the El Nino isn’t that strong, and could break down before winter.  Dr. Ryan Boyles, North Carolina State Climatologist says it’s a week to week affair:

“Through May and June it was really strengthened. Here in recent weeks it has not continued to strengthen as fast. There are some concerns it is going away. It really is a week to week variance. There are a lot of sensors across the tropical Pacific Ocean, a lot of satellites and scientists that are keeping an eye on it. It really affects our seasonal forecasts.”

Boyles says the southern tier of the US wouldn’t be affected by El Nino in the summer, anyway:

“When we have El Ninos in the winter time, it is usually associated with wetter conditions across the Southern US. But in the summer there is not a strong relationship. What happens in the south and west is more driven by what happens with monsoon flow and where in the west they rely on the winter time snow pack for water. So they need a few good snow storms in the winter to replenish it. In the summer with El Nino its not a very strong relationship.”

But, a shift in temperatures in the Pacific does offer a measure of predictability explains Boyles:

“What El Nino does, (El Nino is when the tropical Pacific is warmer than normal, La Nina is when its colder than normal), it gives us predictability. And sense that the coming season will shift one way or the other. When we have El Nino we tend to have wetter conditions in the Carolinas. When we have La Nina we are more likely to have drier conditions in the winter across the Carolinas. But it doesn’t mean the winter wont be wet or dry, it gives us confidence that it will more likely be wet or dry. But it doesn’t by itself dictate the weather we will get in any given month.”

North Carolina State Climatologist Dr. Ryan Boyles.