The historic heat wave that shattered more than 1,500 temperature records across the West last week broke more this week.
That climate change-driven heat was a hit to Colorado’s already record-low snowpack, down to 38% of normal on March 25.
The melt-out forced Buttermilk Mountain to close early, and will likely have far-reaching consequences for Colorado River water users and this summer’s wildfire risk.
Dr. Zachary Labe studies weather patterns for Climate Central, a nonprofit that tracks and communicates climate trends. During a national climate briefing on March 18, Labe highlighted Colorado’s record warm winter.
Labe spoke with Aspen Public Radio’s Michael Fanelli about how unusual the March heatwave was and what it means for the state’s water outlook.
The conversation below has been edited for clarity and length.
Michael Fanelli: Looking back on that heat wave, it seems like it ended up being even hotter than forecasters were expecting. Can you just kind of reflect on what we saw last week?
Zachary Labe: For probably a week leading up to the start of the heat wave, internally, meteorologists, climate scientists, we were all acknowledging that this was going to be a potentially very historic heat wave, especially time of year. I have to keep reminding myself, it's mid-March. And so very much, the forecast, I think, was well forecast with sort of the size and the strength of this heat wave. But you're right. I think temperatures got even hotter than I think a lot of us could have ever expected, again, I'll keep saying, because it's only mid-March. And so I think I lost track after even, like, two or three days into the heat wave, of just the number of records being broken, because we're seeing not just one day and one location that's shattering its all-time highest in March. We're seeing many locations shattering their all-time warmest March temperature, multiple days in a row. In some cases, breaking April temperature records. So yes, it's just been truly shocking, quite honestly, to just reflect on this heat wave and really its persistence, how many days it lasted and for the time of year. So I think truly, it's one of the strongest, most unusual heat domes to impact the Lower 48 U.S. in a very, very long time.
MF: As an expert in this field, is this still surprising to you?
ZL: Yes and no, is it still surprising to me. Spring is arriving earlier, unusually hot temperatures are arriving earlier and earlier in the year. So that part is not surprising at all, and this is very consistent with what we would expect for a changing climate. I think this particular heat wave though, did surprise me. Every now and then we get an extreme event that is just really extreme, and that even for climate scientists, is just really eye-opening. And to me, this was one of them, which I think broke more temperature records than I would have guessed for this time of year. And so, yeah, this event was particularly alarming.
MF: During your climate brief, you spent a lot of time highlighting what's happening here in Colorado. What was it that made you decide to focus on the state?
ZL: One thing prior to this historic heat wave that we've been watching the entire winter has been the snow drought across the West. So for much of winter, or lack of winter, across the West has been featured with really unusually warm temperatures. And so all of this warmth in particular has contributed just to a lack of snowfall. I think when we actually look at the amount of precipitation that fell across the West this winter, it hasn't been that unusually dry. It's not like, record dry. So one of the drivers of the lack of snow in the higher elevations all across the West, but particularly across states like Utah and Colorado, has been really warm temperatures. So I think we wanted to feature the briefing providing these updates of whether there has been any improvement for the snow-water equivalent conditions across the West. Unfortunately, the answer was no, there wasn't really an improvement. And now, after this historic heat wave, unfortunately, conditions have only worsened for snowpack across the entire West.
MF: Is this kind of our new normal, or is this unusual even in a warming world?
ZL: This is still unusual right now. This was certainly an outlier —
MF: We shouldn't expect this every year?
ZL: No, absolutely not. And like I said, we still would expect that — maybe next winter will be unusually cold. I mean, we can't rule that out. So it's certainly not a new normal, in terms of every year, we can expect this record low snow drought. This is an example of an extreme event on top of the long term trend, which is warming. So that's at least what we can say now, moving forward into the future, later in the 21st century, this type of event might not be such an outlier. It might be closer to the norm, but right now, this is still an outlier for our climate.
MF: Looking towards this summer, why is the low snowpack across Colorado and the West so concerning?
ZL: There's a couple different feedbacks at play. So one of them, what we're seeing already, is just very early snow runoff. So all of that water is, instead of sort of slowly melting as we get into spring and in the summer across the highest elevations of the West, we're already seeing rapid melt for even the highest elevations. I just checked the numbers today for the average snow-water equivalent in Colorado. So basically, as it sounds, the sort of an average amount of water being held in the snowpack is already sharply falling, like really rapidly declining, after this heat wave. And so all of that water is already running off. And what that essentially does is, it's going to have potentially significant ecological consequences, because you have such an early spring melt and snow runoff. This could lead to conditions where later on in the summer, you see the soil moisture more quickly dries out. That can also feed back and create more heat. It can also create conditions that are more favorable for wildfire weather. So there's all these sort of long term consequences from this really early melt from the little bit of snow that they did get this winter.
MF: I also thought it was really interesting to learn that this unusually cold East Coast winter that seemed to get so much coverage this season, was actually not that remarkable in historical standards, especially compared to what was happening here in the West, right?
ZL: Right, absolutely. And I think this really goes to our changing perspective on climate. So across the Northeast, I'm located in Pennsylvania, and it felt very cold this winter. And so I think everyone around here has been talking about, “Must have been a record cold winter,” but when you actually look at the rankings, it was pretty unremarkable. If this type of winter had occurred, let's say 50 years ago, nobody would have remembered, because winter temperatures were much more like the conditions we had this year. I was looking at the states and who ranked coldest in terms of most unusually cold, and it still was something only like the 28th coldest winter, I think it was the state of Delaware. So that doesn't stand out at all, despite all of these headlines about the brutal winter the Northeast has had. And again, highlighting that our average temperature is changing. You might not feel it all the time, but it's warming, and we're just getting used to these milder conditions.
