A Strengthening El Nino Could Mean Wet Winter On The West Coast

Transcript

MELISSA BLOCK, HOST:

California could be in for a whole lot of rain this year. El Nino is strengthening in the Pacific. That's the prolonged warming of that ocean around the equator. And to talk about what that means I'm joined by Mike Halpert. He is with the Climate Prediction Center of the National Oceanic and Atmospheric Administration, or NOAA.

Mike, welcome to the program.

MIKE HALPERT: Thank you very much.

BLOCK: And how does El Nino of 2015 look?

HALPERT: At this point, the ocean is roughly one to two, and along the East Coast three degrees, Celsius - above average - so it's doing quite well.

BLOCK: Doing quite well. Well, we're talking about a huge amount of heat energy in the Pacific, right? What are the impacts of that? How is that felt?

HALPERT: Right. Typically, we would see tropical rainfall in the western part of the basin, so over Indonesia and northern Australia, that part of the world. When we see El Nino in the ocean in the central and eastern part of the Pacific warms, that rainfall moves into the central part and even the eastern part of the Pacific Ocean, and areas like Indonesia become drier than average. The rain is now over - largely over the Pacific Ocean. But we've disrupted and changed the pattern of heating into the atmosphere across the Pacific.

BLOCK: And we're seeing the effects of that already?

HALPERT: Well, the biggest impacts that we see in the northern hemisphere will happen in the late fall, through the winter and then into the spring. What we've seen in more episodic type things is that the disruption or the changes in the hurricane seasons in both the Atlantic and the Pacific. El Nino is known to suppress the Atlantic hurricane season and enhance it in the Pacific. And while it's still early in the season, we've certainly seen some pretty impressive hurricanes in the eastern part of the basin, you know, with one just recently delivering its moisture up into California and the southwestern part of the country.

BLOCK: When you look at the measurements that you're seeing and think about what might be in store, especially for Southern California, into the fall and the winter, what does that look like? How strong will El Nino be, do you think?

HALPERT: At this time, the official Climate Prediction Center outlook does favor a strong event, so departures at least a degree and half Celsius above average. In particular, folks commonly think of '82, '83 and '97, '98 as those very strong events. And in both of those cases, all of California really, good parts of the United States, in general, saw very wet winters. But, you know, it's a sample size of two. Now, I don't think we really know enough to draw that distinction.

BLOCK: What about effects on the drought in the West?

HALPERT: Well, obviously California at this point, I think, is hoping for a wet winter, and if El Nino makes that likely, then that's a good thing. Of course, there is always the concern that too much rain in a short period of time can have negative impacts. We saw that just recently with very heavy rains in Southern California that resulted in roads being washed out and landslides. Drought can help to make these things worse in that the dry ground just doesn't really absorb the water and it all ends up running off. And maybe intuitively, it's like, well, wait a minute, we have a drought. But that is something that we could be looking at.

BLOCK: OK. Well, Mike Halpert, thanks for talking with us.

HALPERT: All right. You're quite welcome.

BLOCK: Mike Halpert is deputy director of NOAA's Climate Prediction Center. Transcript provided by NPR, Copyright NPR.