Alaska had its driest June on record this year, but it’s been mostly rainy, especially in Southcentral, since about the first week of July.
National Weather Service climate researcher Brian Brettschneider says that’s when a low-pressure system set up over the Bering Sea, causing moisture to flow from the Pacific Ocean into Alaska.
And Brettschneider says the resulting days upon days of rain, plus a glut of precipitation earlier in the year, have amounted to the wettest year on record in Anchorage through mid-August, even when factoring in the drought conditions earlier this summer.
Brettschneider says, if the shift to rainy weather seemed earlier than usual, that’s because it was.
The following transcript has been lightly edited for clarity.
Brian Brettschneider: Well, we typically see the rainy season set in toward the end of July. I mean, June is a dry month, July is fairly dry, but wetter. And August is a pretty wet month everywhere. So the timing of when the rainy season sets in, it’s not usually as dramatic as it is, say, for the monsoons of Southern Asia or the southwestern lower 48. But there usually is a pretty dramatic rise in precipitation over a week or 10-day period. And it certainly happened about two weeks early this year. But we’ve also had a number of years where the rainy season set in this early or even earlier. And so it’s not exceptional, but it was definitely welcome this year for the fires.
Casey Grove: Definitely nice to see the fire danger signs flipped to the green, “low” danger and stay there. Tell me more about this atmospheric river that’s going to hit Southeast. How big of a deal is that? Would you expect to see landslides as a result? What do you think?
BB: Well, we never forecast landslides. But landslides are certainly more frequent and more common when there is heavy rain or right after heavy rainfall events. So I want to be clear that there’s not a forecast for that, but there is a potent atmospheric river that’s going to rain pretty hard for most of Southeast Alaska for 24 or 36 hours in most places. And it’s forecast to drop two to three, four inches of rain in spots. And that’s a lot for 36 hours. So we should definitely expect rises in streams and and an increased chance of landslides.
CG: And we should mention, just recently in the Mat-Su, there was some flood danger as well, right? The local creeks and rivers were either at bank-full, or I think in maybe one case above, right?
BB: Yeah, there’s been a series of really high total precipitation events. Here in Anchorage, we had a 1.61 inches in 24 hours, which is our heaviest 24-hour precipitation in 18 years. Up in the Valley, they had a couple of very high-end precipitation events, too, over Palmer and to the west and northwest, you know, a station in Hatcher Pass had five inches in like one day. So those are going to have impacts on local streams and create localized flooding conditions. And that’s definitely what we saw.
CG: So, as we’re speaking, today is Election Day in Alaska, the special general election for U.S. House and then also the primary election for the general election in November. And considering it’s been rainy here recently, and it is today, does that discourage people from going out to the polls? Do you know?
BB: So I looked into this a little bit. And there’s a body of research that has looked at correlations between the weather and election participation. And it’s one of those things where people think that, “Oh, yeah, well, this, boy, if it’s bad weather, it’s really going to keep people away from voting.” And it turns out, there’s a very, very small effect, but it’s almost statistically insignificant. To the extent that there is an effect, it does tend to keep people from voting. But again, that’s a lot of noise in perhaps a pretty small signal. So we shouldn’t expect that the weather is going to have a have a material effect on voter turnout.
CG: And I’m assuming those are broader numbers than just in Alaska, where, of course, we are much stronger in hardier than anyone else right?
BB: That is correct. We, you know, walk uphill both ways to the voting booth in the snow and blizzard conditions and so on.
CG: So Brian, what are we looking at going forward here?
BB: It looks like over the next couple of weeks, we actually may break free from our cool and wet pattern. So perhaps a late August, early September, warm dry spell is in our future. And that’s always a tough call, you know, two weeks out, two and a half weeks out. But the signals are looking increasingly strong that high pressure is going to develop over the state and perhaps give us a break from the cool wet pattern we’ve been stuck in for the last five or six weeks.