Climate Change Making Stronger El Ninos, Study Finds

Speaker 1: 00:00 Today, we've got two types of weather conditions to talk about both extreme and at the opposite ends of the spectrum. We're talking about the dry Santa Ana winds. We're all feeling that could easily spark a fire and then the potential of rainy El Nino conditions that could cause a flood. A recent study by the national Academy of scientists suggest we could see more El Nino weather patterns. Alex tardy with the national weather service joins us to talk about how those weather extremes could impact our area. Alex, welcome. Thanks for having me on. Before we get to the prospect of stronger El Ninos, let's look at current weather conditions. Are we still in the middle of a Santa Ana? Speaker 2: 00:38 We are. We're in a transition right now from the first Senate Anna, which developed Sunday, Monday, and I'm sure everyone's feeling it either with the warm temperatures, very warm and there or the dry conditions. Now a new Santa Anna is going to form. In fact, us starting Thursday and roll all the way through Friday. I'm going to, so what's the humidity level right now? So the humidity right now is in the 20s. It's been dropping down into the low teens. To put that in perspective, that's just very dry. Um, and on Thursday and Friday we think it's going to get even dryer, single digit humidity. So that's where you know, your, your hands feel it, your face feels it, your body feels that maybe if you have respiratory, how long until we can say the Santa Ana is over, it looks like a, we'll start losing the wind on Saturday, but it still will be very dry Saturday. So the first day for most of us to feel more normal conditions will be Sunday. Okay. So between now and then, fire risk pretty high. Yeah. And especially a Friday, Speaker 1: 01:39 you know, are the frequency and links of Santa Ana is increasing? Speaker 2: 01:44 Well, um, certainly some years, like this year, so far and a couple of years ago in 2017 [inaudible] we see a frequency, but we also see the lack of rainfall. And so the key is these Santa Ana's are very significant and more impactful when it hasn't rained, especially in the fall. So it's more the fact that we're going longer into the fall without seeing significant rainfall. And are there certain areas of San Diego County that are seeing the worst of Santa Ana winds right now? Well, um, as we get into Thursday, yeah, it'll be places like Valley center, Alpine, uh, all the way up to Julian and Ramona. It's our Foothill areas. But we think the Santa Ana will be strong enough on Friday that even locations along I 15 corridor will feel some of that easterly wind. Speaker 1: 02:35 So El Nino's seem to be the opposite of Santa Ana's. Remind us what they are and where they come from. Speaker 2: 02:42 Yeah, it could not be more opposite. And it's okay to talk about El Ninos now I think because this is actually California flood preparedness week and historically we've associated El Ninos with flooding or heavy rain. So just a quick recap of El Nino. So way up by the equator, South a Hawaii, it's a episode of very warm or unusually warm waters that develop in that area. It's not necessarily climate change. They occur every three to five years where we see the water naturally warming, naturally going away. So El Nino is the warm phase of that episode and historically that has correlated to some of our wet years here in Southern California. Speaker 1: 03:25 And tell us about the recent study of El Nino's by the national Academy of scientists. What did they say about what we can expect in the future? Speaker 2: 03:32 So that particular study and a few others that have occurred really since the 2015 16 El Nino, if we flashed back, that was the strongest El Nino in terms of ocean temperatures being warmer than usual, the strongest one on record. Um, and so a lot of research including that a paper has come out since 2015 16 episode, but we are seeing stronger El Ninos related to the overall Pacific ocean being warmer than usual. So in other words, the Pacific ocean starting off a little bit warmer, especially in the central Pacific and El Nino on top of that may have resulted in that Speaker 1: 04:13 record breaking 2015 16 episode. Now let's talk about that more because you know, if we get stronger and what are El Ninos, which areas of San Diego will be affected most? I imagine Imperial beach for instance, a lot of our coastal communities Speaker 2: 04:27 combined with a little bit of sea level rise, uh, erosion on the coast. Our community's most susceptible. Yeah, we'll be places like Imperial beach, LA Jolla shores, ocean side locations that already are impacted and were impacted in 2015 16 from the big waves. So the one thing with El Nino that's important to remember is it does enhance our JetStream. It does bring storm systems further South often and sometimes even more powerful storm systems. But the other thing is you don't necessarily need to have rain to have impacts. So what we found out in 2015 16 is a lot of our coastal communities had high impact from coastal flooding and erosion from these big storms out in the Pacific that were generating massive swells. Even though some of that rainfall never made it down. Here in Southern California, we still saw a lot of impact with erosion and high waves along our beaches. Speaker 1: 05:26 You know, I'm curious to know because I think many people would expect that these two weather extremes would balance each other out, right? But that's not necessarily the case. If you are in a really dry, arid situation, for example, and then you get a ton of rain dumped down on you, the ground can be too dry to absorb it and you have flooding in places that you wouldn't even typically have flooding in. How do these two extremes, um, how could they impact our area? So in these El Nino situations, it gets really complicated because a lot Speaker 2: 05:58 of times the storms come in and we see a break. So it's all about the timing. If we see repeated storms or consecutive storms that results in the, obviously the most devastating flooding that we see now in terms of the dry conditions. Um, California's done research on drought followed by deluge and, and some of the impacts are significant. So [inaudible] we can have significant flooding even with conditions being very dry initially or when we have repeated storms and the ground is just too saturated. The new problem in California, not necessarily new, but is the wildfire then followed by the flood because the wildfire opens up a whole new threat, which we call a debris flow or mud flow threat. And then maybe even with, with an a significant amount of rain, we then have more brush going into fire season. That's what we're seeing this year. So all the benefits of all the rain last year, uh, it was a very wet year. Speaker 2: 06:59 Most of our mountains and communities on the foothills saw one and a half times more rainfall than an average year. That's resulted in a lot of vegetation and we haven't seen rain really since may of last year. So yes, it's, it's a balancing act. Um, but we're, in reality what we get is not a balance, um, in some of these episodes of either El Nino or episodes of atmospheric rivers, which is often separate. We're seeing more extremes rather than any type of balance. We're not seeing a lot of balance in it. We're seeing more of the extreme, and do we know yet if we are likely to have an El Nino this year, and if so about when can we expect it? So this year we're not expecting an El Nino of any significance. Now, overall, and that study that we talked about, overall, the Pacific is much warmer than it should be. So this year though, it doesn't look like El Nino's in the cards, but that doesn't mean we could not receive a big rainfall event like such as a individual atmospheric river event that may only last for four days. I've been speaking with Alex tardy from the national weather service. Alex, thank you so much. Thanks for having us on again. Speaker 3: 08:16 [inaudible].