Tuesday, June 15, 2010
Chasing the Elusive New Mexico Monsoon Forecast
By John Fleck
Journal Staff Writer
Kerry Jones starts hearing the question every year around this time. What's the monsoon season going to be like? Will it be a wet summer?
A forecaster at the National Weather Service's Albuquerque office, Jones had called to talk about Monsoon Awareness Week, an effort to get the word out about lightning and flash flood safety as the summer rains approach.
But a forecast? Jones and his colleagues don't have much to offer.
As a card-carrying weather wonk, I can get excited about most any meteorological phenomenon. But New Mexico's summer thunderstorms are in a class by themselves. Their towering purple clouds, the smell of humid desert air and the splats as the first big raindrops herald a downpour set my heart racing.
The rains typically arrive the first week of July, give or take a week. But to avoid annoying questions from people like me every time the dew point builds and we see storm clouds on the horizon — "Is this the monsoon?" — the weather service decreed June 15 (today) the Official Start of Monsoon Season.
So welcome to monsoon season! But if you want to know how wet it will be this year, you're out of luck. For folks in the seasonal forecast game, New Mexico's summer rainy season has proved maddeningly elusive.
Working out of a concrete block building off the end of the Albuquerque airport's main east-west runway, Jones and his National Weather Service colleagues are in some sense a victim of their own success.
It's easy to complain about forecasts, but statistics show they have become extraordinarily good at telling us what the weather will be like over the next three to five days.
That extraordinary hot spell two weekends ago? Jones and his colleagues alerted me nearly a week ahead of time. Last January, I watched in awe as a series of epic storms barreled through California and Arizona toward New Mexico, hitting New Mexico exactly when and where the forecasters predicted.
Meanwhile, the weather service's Climate Prediction Center has gotten pretty good at winter seasonal forecasts. Using this past winter's El Niño as a guide, its forecast called for wet weather, especially across southern New Mexico. Check.
So we've come to expect that "Will this summer be wetter or drier than normal?" has a meaningful answer.
But despite more than a decade of serious effort by climate scientists, the National Weather Service's summer forecast maps for the Southwest remain blank, noted University of New Mexico climate researcher Dave Gutzler.
Gutzler has been working on the problem since he came to New Mexico in 1995 and has done as much as anyone to move our understanding forward.
The lack of a forecast is "not because we haven't tried," he told me.
In 1997, Gutzler and student Jessica Preston looked like they might have cracked the problem. Looking at a little more than 20 years of data, they discovered that in years with heavy snowpack on the Colorado Plateau, the summer rainy season tended to be dry in New Mexico.
Apparently, they reasoned, the high country warmed more slowly in those years. And it is that warming in the high country that draws in the moisture that feeds the monsoon.
People like me got excited and started calling Gutzler about this time every year for a forecast.
Three years later, Gutzler wrote a second paper extending the research to longer periods of time. In other periods of history, the snowpack-summer monsoon relationship doesn't work so well, he found.
But while the relationship he and Preston found was not a perfect forecast tool, it's clear they were onto something. Other scientists still cite the paper, and much research has been done trying to build on its insights.
In the years since, Gutzler and his colleagues have looked at the effect of sea surface temperatures, ocean rainfall patterns, wind over the Gulf of California and more.
The forecast problem still stands.
"From a strictly scientific perspective, the story in my mind is how little definitive progress the community has made in improving prediction skill over the past decade," Gutzler wrote in an e-mail last week. "I'm not sure there's a newspaper story there but that seems to me the way the science is playing out here."
But actually, if you want to understand how science works, this turns out to be a great case study.
Movies and textbooks treat science as a fixed body of knowledge — the things researchers have already figured out. But most real science is more like what Gutzler and his colleagues are doing here — poking and prodding in the dark, learning that things are more complicated than they first appeared.
Gutzler thinks scientists understand the monsoon better today. But part of what they understand is that the things that influence its behavior are more complex than scientists realized, making the forecast problem harder than they thought.
"At this point," he said in an interview, "I'm less confident than I was a decade ago."
For a science journalist, that should make the monsoon a great story, a chance to show how science really works. But I admit I've stopped calling Gutzler every year to ask for his forecast.
UpFront is a daily front-page news and opinion column. You can reach John Fleck at email@example.com or 823-3916.