ENSO Alert System Status: El Niño Watch
Synopsis: Borderline ENSO-neutral/ weak El Niño conditions are expected to continue into Northern Hemisphere winter 2012-13, possibly strengthening during the next few months.
During September 2012, the trend towards El Niño slowed in several key oceanic and atmospheric indicators. However, the Pacific basin reflects borderline ENSO-neutral/ weak El Niño conditions. Equatorial sea surface temperatures (SST) remained elevated across the Pacific Ocean (Fig. 1), although anomalies decreased during the month as indicated by weekly index values in the Niño regions (Fig. 2). The oceanic heat content (average temperature in the upper 300m of the ocean) anomalies also weakened (Fig. 3), but continued to show large regions of above-average temperatures at depth across the equatorial Pacific (Fig. 4). Interestingly, low-level westerly wind anomalies were evident over the equatorial western Pacific Ocean (Fig. 5), which may portend possible strengthening of the subsurface anomalies in the coming months. Despite these winds, the atmosphere was still largely ENSO-neutral, as reflected by the Southern Oscillation index and near-average upper-level and lower-level winds across much of the Pacific. Tropical convection increased near the Date Line, which is consistent with weak El Niño conditions, but also remained elevated over eastern Indonesia, which is further westward than expected (Fig. 6). Thus, the atmosphere and ocean indicate borderline ENSO-neutral/ weak El Niño conditions.
Compared to the past few months, the chance is reduced for El Niño to develop during Northern Hemisphere fall/winter 2012-13 (see CPC/IRI consensus forecast). Due to the recent slowdown in the development of El Nino, it is not clear whether a fully coupled El Niño will emerge. The majority of models indicate that borderline ENSO-neutral/ weak El Niño conditions will continue, and about half suggest that El Niño could develop, but remain weak (Fig. 7). The official forecast therefore favors the continuation of borderline ENSO-neutral/ weak El Niño conditions into Northern Hemisphere winter 2012-13, with the possibility of strengthening during the next few months.
This discussion is a consolidated effort of the National Oceanic and Atmospheric Administration (NOAA), NOAA’s National Weather Service, and their funded institutions. Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center web site (El Niño/La Niña Current Conditions and Expert Discussions). Forecasts for the evolution of El Niño/La Niña are updated monthly in the Forecast Forum section of CPC’s Climate Diagnostics Bulletin. The next ENSO Diagnostics Discussion is scheduled for 8 November 2012. To receive an e-mail notification when the monthly ENSO Diagnostic Discussions are released, please send an e-mail message to: firstname.lastname@example.org.
WHAT THE REPORT MEANS TO ME…………JR
Compared to the past few months, the chance is reduced for the development of a full El Niño during the Northern Hemisphere fall/winter 2012-2013. The majority of models indicate a borderline ENSO-neutral/weak El Niño to continue and a little less than half of the models suggest that a weak El Niño could develop but remain weak. The official NWS forecast favors the continuation of borderline ENSO-neutral/weak El Niño for the next few months, with the possibility of strengthening in the coming months… Whatever develops from these forecasts, it doesn’t bode well for a normal/average winter H2O.
A cornfield in Nebraska, which has been suffering from drought.
WASHINGTON — A season of warmer ocean waters that has been expected to produce a Niño episode and perhaps bring relief from the continuing drought may turn out to be a bit weaker than advertised, according to climate experts.
The periodic upwelling of warmer waters in the eastern equatorial Pacific can be one of the most telling calls that a climatologist can make. A powerful Niño can drive global patterns of drought, storm, snow and flood, with big consequences for farmers and fishermen, relief organizations and reservoir operators, schoolchildren and ski bums.
But after seeing signals for months that a moderate Niño might be arriving right about now, the more likely case appears to be an episode that is weak indeed: probably short, and hardly nasty or brutish.
Scientists who predict the weather months in advance pay close attention to back-and-forth swings in what they call El Niño Southern Oscillation, or ENSO, which includes the mirror-image oceanic cooling called La Niña that probably made the past year’s drought worse. And recently they have been peering at their computer models from the edge of their seats, eager to detect the latest change.
“We believe that there will be an El Niño, but the strength of it is debatable, and it may be a fairly weak one,” said Huug van den Dool, a meteorologist at the federal government’s Climate Prediction Center.
“The bigger the El Niño, the bigger the effect,” said David Neelin, a professor of atmospheric and oceanic science at the University of California, Los Angeles. “This may be El Niño manqué, a borderline El Niño — a wannabe El Niño.
Ok El Nino is playing some October games with the winter ahead. Check out the new outlook and ocean temps in the Pacific.
I am not sure of your geographical area of interest. The first two graphs are for your NW San Juan Mountain drainage. Other drainages look somewhat similar, though the San Juan River group has had better runoff earlier this season than on your (north) side of the San Juan ridge (see figure 3). Figures 4 and 5 are percent of normal and departure from normal precipitation for all of Colorado this year. Finally at the bottom are some monthly precipitation data for Ridgway and Silverton.
You can see that this year is very dry but is not as dry as 2002. In addition, 2002 was preceded by two dry seasons, so all fuels even large fuels (such as large conifer trees) were under drought stress. Also reservoirs in 2002 were lower than they are this year which raised irrigation/agricultural drought concerns.
In ‘Patagonia,’ Pristine Rivers And A Plan For Dams—Directed by a former Prescott College student of mine…
The Baker River is one of two waterways that would be dammed in a proposed hydroelectric project in the fabled Patagonia region of Chile. This section of the river would become a reservoir under the plan.
The way the Andes divide Patagonia, Argentina gets most of the land and Chile most of the water. As shown in Patagonia Rising, a new documentary, the landscape on Chile’s side of the border is similar to coastal British Columbia or the Alaska panhandle: chilly, forested, mountainous and very wet.
As in many other Latin American countries, the water doesn’t belong to the people: The government utility that once controlled it has been privatized and is now owned mostly by European investors. Their goal is to dam the cascading rivers to generate electricity for the country’s north.Patagonia Rising makes a clear, if not particularly impassioned, case against this plan, which is well along the course to approval.
Five dams would rise on the Baker and Pascua Rivers, a $7 billion project in an area that currently lacks roads and utilities. The residents are mostly farmers who still travel by horse and ox cart; the only ones who have electricity get it from solar panels. There’s no Internet or cellphone service, although some people did recently get ham radios.
Director-editor-cameraman BRIAN LILLA’S film offers stunning views of the region and evocative glimpses of a near-vanished agrarian lifestyle. It also turns to environmental experts — mostly North American — to explain the effects of damming large rivers. These consequences turn out to be global.
On a regional level, the five dams would displace longtime inhabitants, degrade water quality and dramatically change the landscape. They could destabilize the area’s “warm glaciers,” which are just slightly below freezing and thus easily liquefied, and cause ruinous floods. The dams will also undermine a small but lucrative ecotourism trade.
Plus, they would generate electricity far from the market for it: The high-voltage transmission lines would have to run through a 1,200-mile clear-cut corridor to Santiago.
Patrick McCully, the Irish-American executive director of California-based International Rivers, looks beyond the immediate area. “Big dams destroy rivers,” he says, and are among the leading causes of extinction of freshwater creatures. They also deprive oceans of nutrients, leading to dead zones, loss of sea life and a lessened ability to moderate the planet’s climate.
Large dams are an archaic means of generating power, adds Stephen Hall, co-author of a National Resources Defense Council report on energy. He notes that Chile is well-positioned to produce electricity by wind, geothermal and solar energy; its northern desert is one of the globe’s most promising solar sites. In addition, he argues, as much as half of the juice generated by the seven dams could be replaced simply by modernizing Chile’s electrical use and grid.
The filmmaker also interviews proponents of the dam, including a corporate spokesman, people on the street in Santiago and Patagonian residents who expect to benefit from the construction. But their remarks tend to be shallow or self-interested.
The Atlantic Ocean, especially the North Atlantic, is peculiar: Every few decades, the average temperature of surface water there changes dramatically.
Scientists want to know why that is, especially because these temperature shifts affect the weather. New research suggests that human activity is part of the cause.
Scientists originally thought that maybe some mysterious pattern in deep-ocean currents, such as an invisible hand stirring a giant bathtub, created this temperature see-saw.
And that may be part of it. But there’s a new idea: The cause isn’t in the water; it’s above it — a kind of air pollution called aerosols.
Ben Booth, a climate scientist at Britain’s Met Office Hadley Center, says that aerosols create clouds.
“The more aerosols you have, the more places there are for water vapor to condense,” he says. “And so what aerosols do is they cool.”
They cool the ocean because clouds reflect sunlight back into space before it can hit the ocean.
Aerosols are fine particles like soot or sulfur compounds, mostly from burning fuel. They seed a kind of cloud that’s especially good at reflecting solar radiation back into space. Even on their own, without clouds, these aerosols act like sunblock.
Yesterday, we took a look at invisible winds suddenly made visible, streaming across the Earth. This being the blustery season, I’ve got more wind today, this time streaming across the sea, but looking uncannily like a van Gogh sky.
Most of the surface currents in the ocean are shaped by wind. In this visualization from the folks at NASA, the ocean is rich with lazy spirals that move in great circular sweeps (called “gyres”) clockwise in the northern hemisphere, counterclockwise in the south. Think of the ocean surface here as a reflection of the winds above, a kind of watery mirror (though the spinning of the Earth, tugs of sun and moon and obstruction of continents play a part.) Click on this video, and you’ll see the dance of wind-on-water everywhere.
I like watching the Gulf Stream roar past the tip of Florida in the beginning, all white and purposeful, heading up the North American coast. There’s something playful about water and wind bumping into large land masses likeAfrica, breaking into whirligig spirals, spinning along the shore. Then there’s the equator, which in this version seems almost wall-like. As the winds approach it, they flatten into jet like streams racing along a corridor.
What this map doesn’t show is the newest discovery created by ocean gyres. It’s called the Great Pacific Garbage Patch, a vast, Texas-sized clump of human garbage floating in the Pacific. Created by a convergence of ocean currents and wind somewhere betweenHawaii andCalifornia, it’s not visible from satellites. Apparently, a thick blanket of pop bottles and chemical sludge sinks a little below the surface so it can’t be seen from above and, anyway, it turns out garbage doesn’t clump in a spiral; it looks more like a Nickelodeon splat, so if we could see the Garbage Patch, it would ruin the mood created here.
This is an image of wild wind, water and spiral beauty. And what does it say about us that our first human mark is a splat that feels like we’ve dropped some mud onto a van Gogh painting?
April 11, 9:47 a.m. | Updated with a reaction from Stefan Rahmstorf below |
Here’s a followup to my piece on how greenhouse-driven warming is loading the dice toward more hot weather extremes. In late March, the journal Nature: Climate Change published a “perspective” article by Dim Coumou and Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research titled “A decade of weather extremes.” The piece, discussed by its authors on the RealClimate blog, was widely cited in news accounts and blogs as new scientific analysis.
The article summary is here:
The ostensibly large number of recent extreme weather events has triggered intensive discussions, both in- and outside the scientific community, on whether they are related to global warming. Here, we review the evidence and argue that for some types of extreme — notably heatwaves, but also precipitation extremes — there is now strong evidence linking specific events or an increase in their numbers to the human influence on climate. For other types of extreme, such as storms, the available evidence is less conclusive, but based on observed trends and basic physical concepts it is nevertheless plausible to expect an increase.
I sent the article around to some researchers working on these questions. Here are their reactions, along with another valuable assessment posted by Michael Tobis at Planet 3.0:
Daffodils bloomed in St James’s Park in London on March 1.
Some people call what has been happening the last few years “weather weirding,” and March is turning out to be a fine example.
As a surreal heat wave was peaking across much of the nation last week, pools and beaches drew crowds, some farmers planted their crops six weeks early, and trees burst into bloom. “The trees said: ‘Aha! Let’s get going!’ ” said Peter Purinton, a maple syrup producer in Vermont. “ ‘Spring is here!’ ”
Now, of course, a cold snap in Northern states has brought some of the lowest temperatures of the season, with damage to tree crops alone likely to be in the millions of dollars.
Lurching from one weather extreme to another seems to have become routine across the Northern Hemisphere. Parts of the United States may be shivering now, but Scotland is setting heat records. Across Europe, people died by the hundreds during a severe cold wave in the first half of February, but a week later revelers in Paris were strolling down the Champs-Élysées in their shirt-sleeves.
Does science have a clue what is going on?
The short answer appears to be: not quite.
The longer answer is that researchers are developing theories that, should they withstand critical scrutiny, may tie at least some of the erratic weather to global warming. Specifically, suspicion is focused these days on the drastic decline of sea ice in the Arctic, which is believed to be a direct consequence of the human release of greenhouse gases.
“Dad, what causes wind?” asks 6-year-old Calvin (of the comic strip Calvin and Hobbes).
“Trees sneezing,” his dad explains.
“Really?” says Calvin, amazed.
“No,” says Dad, “but the truth is more complicated.”
Well, it’s not that complicated. I can do better than Calvin’s dad. And anyway, I’ve just discovered a video (see below) that makes wind startlingly beautiful to think about. If only Calvin were around to show it to. What causes wind?
Well, wind begins with difference.
Little Cloud On A Sunny Day
Think of a patch of ground on a sunny day. Sunshine pours down. The air gets warmer. Along comes a cloud, not a big one, but big enough to cast a shadow. The air in that shadow cools a little.
Now we’ve got a difference: cool air is sitting next to warm air — and the air that’s warming up is getting lighter. The air that’s cooling down is getting heavier, and as the warmer air rises, the sinking cooler air slips in to take its place. That slipping in? You feel it as a gentle push against your cheek; that’s the beginning of a breeze.
Breezes, blustery days, wind — all come from warm and cool air slipping, sliding, tumbling, like kittens at play, across the earth. Normally you can’t see this happening, but two designers, Fernanda Viegas and Martin Wattenberg, have just made a moving map of the wind. If you were a wind god gazing down at America, this is what you’d see. This isn’t a painting. It’s the real deal, taken from the government’s National Digital Forecast database.
A couple enjoy a sunny afternoon against the backdrop of the Midtown skyline from Piedmont Park in Atlanta in late March.
Across the country, more than 7,700 daily temperature records were broken last month, on the heels of the fourth warmest winter on record.
While it might be time to lie on a blanket in the park, climate scientists are worried. They say all these sunny days are actually an extreme weather event, one with local and global implications. READ/LISTEN……
Bridger Bowl Wet Slab, March 27, 2012
Many people that saw the photos of the avalanches from Bridger Bowl yesterday were probably scratching their heads, wonder why runs that were so skier compacted would slide. Thanks to the Gallatin National Forest Avalanche Center and Bridger Bowl Ski Patrol we now have some answers. This informative video discusses why such slides can occur. The sheer destruction is pretty incredible. Thanks to Gallatin National Forest Avalanche Center and Bridger Bowl for such an informative video.
WATCH……SOMETHING TO KEEP IN MIND DURING SPRING WARM UP especially with the winter we’ve had in the San Juans. JR
I’m riding in the backseat of a vintage 1948 Buick RoadMaster running late for a flight at the Santiago airport. My head rings with a Pisco buzz, the result of a four hour lunch at the El Perón with an old friend. We reviewed lies and good times that we’ve shared while skiing the Rockies and Andes and in other adventures. In my mind I compare the old ride, belching out fumes and rattling down the highway to my old friend, Señor Tim Lane. Both genuine, classic originals…..
Peter Shelton second from right, enjoying lunch with old friends in Rio Blanco Chile……………………
We interrupt this Catalina Island coming-of-age trilogy to comment on the recent spate of avalanche deaths.
I wrote the news story this week about 18-year-old Norwood student Garrett Carothers, and it broke my heart. “Dear, sweet Garrett,” read the caption on a Facebook photo.
By all accounts Carothers and his snowmobiling friends and family were not behaving badly on Saturday when the last in line of their little motorized train was snuffed by an avalanche that released above them. They weren’t high-marking some wind-loaded, primed-to-slide alpine bowl. They were struggling in deep snow on a summer road and had decided to turn around. Too late, as it turned out. Innocents abroad.
Other accidents recently in the news revealed evidence of hubris. In November, there was famous skier, cliff jumper Jamie Pierre, ignoring all the classic signs of instability, including natural and triggered releases everywhere around him, to attempt a narrow, thinly covered chute at Snowbird before the ski area was open. The moving snow didn’t kill him, the rocks he bashed over did. He was beloved, too.
On Stevens Pass in Washington, a giant, unwieldy group of “experts and industry insiders,” 13 of them, decided to ski off the backside of the ski area immediately following a two-day, 26-inch storm that came with strong winds. They claimed they were using proper protocol – skiing one at a time, stopping in safe zones – but somehow five of them got caught by a monster slide. Three were buried and killed.
Then, there was Telluride’s own Nate Soules tragedy, though I don’t use that word. Soules chose to snowboard into Bear Creek, alone, on the first real powder day in a long time, with two inches of water and all of that attendant weight added to an especially rotten San Juans snowpack. He knew what he was doing. But he was blinded by what long-time avalanche forecaster Jerry Roberts calls powder shock. You’re not supposed to speak ill of the dead, but I was mad at him then, and I’m still mad. As a father and grandfather. Yes, as many have said, he died doing what he loved. But he also loved his wife and young son. What was he thinking?
I haven’t skied the backcountry for a few years now, after devoting the better part of the last 40 years to it. The reasons are complex and include two hip-replacement surgeries and the digging out, just before the first hip, of a friend who barely survived an avalanche on Red Mountain Pass. That friend was one of the most knowledgable and conservative wild-snow skiers I have known. His triggering a big slide, and getting tumbled and crushed blue by the weight of the snow on top of him seemed to prove the adage: that if you are out there enough, you will eventually get caught.
Chris Laundry observing avalanche mitigation on RMP. J. Roberts photo
WESTERN SLOPE – The Colorado River Basin is losing water at an ever-accelerating rate, and snow scientist Chris Landry wants people to know about it.
But spend a day with Landry, and you will accumulate more questions than answers: How much snow falls (or doesn’t); how dense and water-laden it is (or isn’t); and is there enough of it to reflect surface radiation back into the atmosphere and preserve it, or is it destined to continue to melt away earlier every coming year?
Each winter since 2003, Landry, the director of the Center for Snow and Avalanche Studies, a research organization in Silverton, has been on the job at his two research plots, Swamp Angel and Senator Beck Basin, near the summit of Red Mountain Pass. Here, Landry digs over 100 snow pits over the course of each winter to observe the layers of dust that accumulate on this outlying garrison of Colorado mountain ranges.
J. Roberts photo Snow/Water equivalency scale
WESTERN SAN JUANS – As snow continues to fly across Colorado on a steady basis, bringing a sense of winter normalcy back to most areas, state snowpack levels have improved. But to realize an average end-of-season snowpack after a dismally dry start to the season, March needs to be a very, very snowy month.
“If you look where the statewide snowpack totals are right now, we are where we typically should be on February first. As snowpack levels go, we are kind of a month behind,” said Natural Resources Conservation Service Snow Survey Supervisor Mage Skordahl on Monday. “Currently we are at 77 percent average statewide, which is an improvement from 72 percent at the beginning of February. The percent of average snowfall needed next month (to get to 100 percent average) is 178 percent of average. We are still playing catch-up.”
After a high pressure ridge kept most of Colorado relatively dry in December and for the first part of January, the Pacific jet stream finally shifted southward and positioned itself over southern Wyoming and northern and Central Colorado, bringing precipitation to basins to the west of the Continental Divide. Relatively speaking, Colorado’s southern mountains had a better start to the winter than the central and northern Mountains. But as a typical La Nina precipitation and snowfall pattern returned to Colorado in January, the southern basins saw a significant decrease in precipitation.
Avalanche forecaster Jerry Roberts and I are riding in his orange welfare rig. We’re on our way to check storm boards for recent snow accumulation totals. It’s the middle of the night. Our tires leave tracks several inches deep. Snowflakes in the air stop, eerily, strobe-like, in each sweep of the yellow flossing light on the roof…..
“3-Mary-14, this is 3-Mary 51. Come in Doug.” ”Ya, Jerry, this is 14. I’m over in Ironton Park on my way up. It’s snowing pretty hard. Visibility is pretty poor. See you on the pass.”
“I’ve got a lot of respect for the plow drivers,” Jerry says working the defroster to keep the wipers from icing up completely. ”Man, that’s a lonely, hateful job. Ninety percent boredom and 10 percent terror.”
‘RED MOUNTAIN PASS – CHIEF OURAY HIGHWAY: A History of Forecasting and Mitigation.’—Jerry Roberts—The Avalanche Review
Gary King photo
The Avalanche Review, February & April 2009
It’s anybody’s guess why forecasters do this job. It could be the smell of powder, throwing 50 pound shots from the helicopter, watching hard slab failure release energy over several alpine basins at once, or maybe just the company you keep.
Whatever the reasons, you get hooked on the excitement and the challenges of the job. It requires a lot of field experience (series of non-fatal errors), collection of empirical evidence, listening to your inner voice (intuition), and distilling all of the variables to reduce uncertainties until you can finally make a decision that you can live with. There are many truths to be learned. It’s no big mystery; you pay attention and do your work because you don’t want to be a victim of your own bad planning. It helps to be comfortable in the world of uncertainties.
The radio chattered with the “heads up” signal, and a few seconds later we heard the boom of the gun, and then the eerie sounding whistle of the bullet piercing the air. Then the second report of the charge exploding somewhere up in the cloud obscured ridge. We chatted nonchalantly–all of us had watched expectantly as round after round was lobbed into the paths near town with no result. Surely the first shot wouldn’t do anything here.
And then we saw it: the pristine white snow all the way across the starting zone appeared to be cracking like ice. I lifted my camera to my eye and started pushing the button over and over again as the huge slabs of snow succumbed to gravity and began moving down the mountain, then turning into a great white cloud, and then into a 100-foot high locomotive. It kept gathering speed, kept growing. When it was about halfway to the creek, I looked up from the camera’s viewfinder. The Prescott students are already in retreat, on the highway and moving tentatively toward the elusive safe zone. Only Roberts and I were still perched on the snow bank and he had a strange, elated, frightened look on his face.
I waited for him to say something, for him to utter some transcendent haiku about the beauty and the power of snow, about staring death in the face and laughing, about pisco, Chilean cantinas, orange welfare rigs, or that final , poignant look on an angry, disappointed lover’s face as she walks out the door for the last time.
But the haiku never came. The Zen in Jerry Roberts had vanished. All that remained was the redneck.
“RUN LIKE BASTARDS” he yelled, then jumped off the snow bank and sprinted up the road.
‘Snow & Avalanche Forecasting Education-Prescott College’–Jerry Roberts–The Avalanche Review, December 2002
The idea was birthed over a bottle of good pisco on a stormy January night in the early 80′s in Chattanooga, Colorado, just below Red Mountain Pass. Tim Lane was persuading David Lovejoy, jefe of Outdoor Education at Prescott College that he needed to give his winter mountaineering students, who were camped just outside the cabin door, something more substantial than a pinche three day search and rescue course.
The pisco was about finished when Lovejoy agreed that the college might be interested in a more structured avalanche program and if we were interested in developing one, a formal proposal should be sent. Surprisingly the proposal got written on the old typer and was shipped off into the Arizona desert. Over 25 years later the program is still alive…. ….
I finally contacted my old friend and NWS weather forecaster and guru, Joe Ramey at the Grand Junction, National Weather Service and asked him… “Joe, what’s going on with our San Juan mountain weather this season??”From: Joe RameyHappy New Year Jerry, that is if you can be happy with less snow. I wasn’t too worried through December when the pattern was overly amplified. With the big ridge offf the west coast the storms were diving due south through the inter-mtn west producing only light snow here in western Colorado. By Christmas we could see that pattern breaking down to a less amplified more progressive pattern with the storms tracking across the northern tier of states, which is typical of La Nina. Also January has a strong snowy climate signal under La Nina conditions. This held out hope for increased snowfall at least favoring the northern mtns. But that pattern devolved into this moderately amplified pattern with the ridge in the eastern Pacific again blocking us from the storm path.Now I am getting worrried with this pattern progged to persist for the next 10 days at least.Current Snotel sites are running roughly 60-70% of average for this date (Upper Rio Grand and Arkansas are still higher from the upslope events in Dec) ftp://ftp.wcc.nrcs.usda.gov/data/snow/update/co.txt and of course these percentages will be dropping significantly over the next week or more.The storm for Saturday is still only producing 1-3 inches in the mtns north of highway 50. The official 6-10 and 8-14 day forecasts reflect this pattern with increased probabilities of below normal precipitation. http://www.crh.noaa.gov/climate/main.php?type=outlook&page=temp_pcpn.php The longer Jan-Feb-Mar seasonal outlook still holds on to the La Nina pattern of increased snowfall across the north.Crossing all my appendages with hopes for a pattern change…before its too late!
A dust storm in Phoenix in July. Scientists say it is hard to gauge the cleanliness of Western air.
DENVER — Oh say, can you see across the Grand Canyon? Not as well as you used to on some days.
The question of how clean the air is in the American West has never been an easy one to answer, strange to say. And now scientists say it is getting harder, with implications that ripple out in surprising ways, from the kitchen faucets of Los Angeles to public health clinics in canyon-land Utah to the economics of tourism.
It is at least partly about dust, something that has been entwined with Western life for a long time, and now appears to be getting worse.
But now a new and even more complicated chapter appears to be unfolding, researchers in many different fields say. From off-road vehicle use, which has in some places replaced the clumping trod of the old cattle herds, to drought’s impact on plants with their soil-anchoring roots, more dust appears to be up and moving.
And scientists say they are also understanding for the first time the deep connections between the dust’s main source — a vast high-desert region called the Colorado Plateau, which stretches through four states and is home to national parks like the Grand Canyon and Arches — and the economic, environmental and demographic life in cities and suburbs far removed.
In the last few years, winter dust storms on the high peaks of the Rocky Mountains in Colorado have sharply increased in number, affecting the rate of melting snows into the Colorado River, a main source of water for agriculture and for the drinking supply for more than 20 million people. Of 65 so-called dust-on-snow events since 2003, when tracking began, 32 have struck in just the last three years, according to the Center for Snow and Avalanche Studies, a nonprofit research group based in Silverton, Colo. Dust can accelerate how fast snow melts because it absorbs heat.
“It’s not a mysterious process,” said Chris Landry, the organization’s executive director. “Anybody who has thrown coal dust on their driveway or sidewalk to melt it down knows the theory.”
EL NIÑO/SOUTHERN OSCILLATION (ENSO) DIAGNOSTIC DISCUSSION issued by CLIMATE PREDICTION CENTER/NCEP/NWS 8 December 2011
ENSO Alert System Status: La Niña Advisory Synopsis: La Niña is expected to continue through the Northern Hemisphere winter 2011-12.
During November 2011, below-average sea surface temperatures (SST) associated with La Niña conditions continued across the eastern and central equatorial Pacific Ocean (Fig. 1). The recent weekly SST indices in the Niño-3.4 and Niño-3 regions maintained levels near –1.0°C (Fig. 2), indicative of weak to moderate La Niña. The oceanic heat content (average temperature in the upper 300m of the ocean, Fig. 3) weakened slightly, but still indicates a large area of below-average temperatures at depth in the eastern Pacific (Fig. 4). Also reflecting La Niña, the atmospheric circulation over the global tropics featured anomalous low-level easterly and upper-level westerly winds in the central and west-central Pacific. Averaged over the month, convection was suppressed near and just west of the Date Line and enhanced over northern Australia and parts of Indonesia (Fig. 5). Collectively, these oceanic and atmospheric patterns are consistent with the continuation of La Niña conditions.
A majority of the models predict a weak or moderate strength La Niña to continue through the Northern Hemisphere winter (Fig. 6) and then gradually weaken after peaking during the December – January period. The models are roughly split between those that predict La Niña to remain weak (3- month average in the Nino-3.4 region between -0.5 and -0.9°C) and those that predict a stronger episode. Over the last half-century, La Niña events that were preceded by ENSO-neutral conditions during the Northern Hemisphere summer (May-August) were less likely to attain strong amplitude (stronger than – 1.5°C) the following winter. This observation, in combination with the model forecasts, favors a weak- to-moderate strength La Niña during the Northern Hemisphere winter, likely weakening with the onset of northern spring.
During December 2011 – February 2012, there is an increased chance of above-average temperatures across the south-central and southeastern U.S. below-average temperatures over the western and north-central U.S. Also, above-average precipitation is favored across the northern tier of states, excluding New England, and drier-than-average conditions are more likely across the southern tier of the U.S. (see 3-month seasonal outlook released on 17 November 2011).
This discussion is a consolidated effort of the National Oceanic and Atmospheric Administration (NOAA), NOAA’s National Weather Service, and their funded institutions. Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center web site (El Niño/La Niña Current Conditions and Expert Discussions). Forecasts for the evolution of El Niño/La Niña are updated monthly in the Forecast Forum section of CPC’s Climate Diagnostics Bulletin. The next ENSO Diagnostics Discussion is scheduled for 5 January 2012. To receive an e-mail notification when the monthly ENSO Diagnostic Discussions are released, please send an e-mail message to: email@example.com.
ENSO is predicting warmer temperatures and less precipitation for the southern tier states (that’s us, especially south of I-70 in Colorado) through February. JR