It's likely that Alaska and, really, the rest of the globe will see a very strong El Niño climate pattern this fall and winter.
As it turns out, we're already in an El Niño, typically known to promote warmer weather. But the somewhat technical designation of a "very strong" El Niño -- which some of the more hyperbolic forecasters are calling a "super" El Niño or a "Godzilla" El Niño -- comes from water temperatures being 2 or more degrees Celsius above normal in a bellwether patch of the central Pacific Ocean.
And National Weather Service climate researcher Brian Brettschneider -- back for another Ask a Climatologist segment -- told Alaska Public Media's Casey Grove that we've only ever seen a very strong El Niño a handful of times in recorded history.
This interview has been lightly edited for length and clarity.
Brian Brettschneider: The strength of an El Niño doesn't correlate with the strength of the impacts. It becomes more likely that you will have typical impacts. So if if we're typically warm in winter in an El Niño, the stronger the El Niño, the more likely we are to be warm, but not the warmer we're supposed to be. That said, in the case of some of these really, really strong El Niños, and the current forecast is for us to essentially compete with the strongest that's ever been recorded. You know that's a big statement. And there's a lot of all of our best computer models are saying, "Yeah, this will be at least as strong as the record, and very likely stronger than the the current record holder." But it seems like when we have those really, really strong events, it almost is so extreme that that warm push of air that we typically get gets shunted even farther to the east, and so it's kind of directed toward, maybe, southeast and British Columbia, and maybe not quite as extreme here in Alaska. But again, we want to be cautious because there's only a couple of examples to go on.
Casey Grove: Yeah, I mean it is pretty striking, though, Like you said, this has only happened four times in recorded memory, and that this is either going to match that or break those records. I mean, with that caveat that there's plenty of variability, and we don't know exactly what's going to happen, would you expect, for instance, more severe or or more frequent big storms like we saw with the remnants of Typhoon Halong that devastated parts of Western Alaska?
BB: So we want to be really careful, because it's this is a season-long event. So there's no storm that we say, "This is an El Niño storm." That's really something that is, not only just kind of frowned upon, it's irresponsible to do that. So you're being irresponsible, Casey.
CG: As usual.
BB: No, but that said, the whole global ocean is much warmer than it's been ever, and so you need warm ocean to sustain tropical cyclones. And now we actually have a physically larger area that can sustain cyclones. So if there was one, it could perhaps retain its strength and its tropical characteristics farther north than would otherwise be expected.
That also means you could have a storm forming farther north, perhaps like Merbok did. Merbok formed in an area where storms aren't supposed to form, because there was now warm enough water. So you could, in theory, have a situation like that again. But we are not saying a typhoon, ex-typhoon remnants, are more likely in Alaska or less likely. But you could make arguments in several ways why that might be a little bit more likely to happen versus not. But we also want to remember these are low-probability events. I know it's happened twice in the last decade, but you know, even if you double the chances of a low-probability event, it's still a low-probability event. And so people should not expect that it's going to happen but, as always, should be prepared that, in our new world, that these things are a reality now.
CG: And maybe a little more on the lighter side of things, should I be prepared to leave my snowboard in my shed and my skis hanging up? Is it a foregone conclusion with perhaps a warmer winter that we will have a bad snow winter?
BB: Of all the climatological statistical relationships with El Niño in winter, the strongest is low-snow winters across the mainland of Alaska. And so I'm already sad about our upcoming winter, and that it's going to be probably low on snow, or that that's the the favored outcome. We could always get lucky and have a good snow winter, but more times than not, the El Niño winter, a strong El Niño winter, is a low-snow winter.
And that's a combination of more of the precipitation falling as rain, but also generally just being drier. We generally have more of a, in the mainland, more of a southeasterly flow, which means the moisture gets caught up on the coastal mountains, and so we get a rain shadow from the Chugach and Talkeenas and the Alaska Range, and and they all kind of tend to dry the atmosphere out.
