Weather Post by Dr. Ryan Maue
The Atacama desert in Chile described as the driest place on Earth just got walloped by an extreme cold front (climate change) and was buried in snow.
From NDTV: (with video coverage)
According to the national emergency centre in Chile, the area had not seen this amount of snow in close to 20 years. Some areas received up to 80 centimeters (32 inches) of snow, leading to closed roads and stuck vehicles. The temperature in Santiago, Chile dropped to as low as -8.5 degrees Celsius on Wednesday. Other countries in Latin America such as Uruguay and Argentina have also been affected by the cold front.
Indeed, temperatures over much of middle-latitudes South America have been averaging 5°-10° C below normal for the past week.
From Wikipedia’s excellent article on the Atacama Desert:
Some parts of Atacama Desert, especially, surroundings of the abandoned Yungay town(in Antofagasta Region, Chile) are arguably the driest places on Earth,and are virtually sterile because they are blocked from moisture on both sides by the Andes mountains and by the Chilean Coast Range. A coastal inversion layer created by the cold Humboldt Current and the anticyclone of the Pacific is essential to keeping the climate of the Atacama dry. The average rainfall in the Chilean region of Antofagasta is just 1 millimetre (0.04 in) per year. Some weather stations in the Atacama have never received rain. Evidence suggests that the Atacama may not have had any significant rainfall from 1570 to 1971. It is so arid that mountains that reach as high as 6,885 metres (22,589 ft) are completely free of glaciers and, in the southern part from 25°S to 27°S, may have been glacier-free throughout the Quaternary, though permafrost extends down to an altitude of 4,400 metres (14,400 ft) and is continuous above 5,600 metres (18,400 ft). Studies by a group of British scientists have suggested that some river beds have been dry for 120,000 years.
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In order to get moisture into the desert, it must get into the so-called rainshadow. A possible route is from the NNW, which would require a slug of high-precipitable water or moist air to travel poleward along the South American west coast. Currently, a cut-off low or upper-level potential vorticity anomaly is spinning happily off the Chilean coast — and the clockwise flow (cyclonic in the Southern Hemisphere) is distinctly opposite to the typical anti-cyclone situated in that location. From the most recent week of Precipitable Water animation: all sorts of extreme weather can be found, including Tropical Storm Arlene, it’s landfall and remnants flooding the American Southwest (thunderstorms fueling haboobs), as well as the Atacama snowfall. Click on the image to watch the last week (Java Animation) of precipitable water and low-level wind flow from FSU Maps site.
The July 7, 00Z NCEP GFS global model forecast has additional snowfall for Chile during the next week: Image Link…
Dave Springer says:
Small point Dave. The Atacama desert has the driest place on Earth. There are some places there where it has never rained in recorded history. Antarctica is the driest continent on average, but it still snows at all locations there, at least a little.
Now if archaeologists can only discover some coal burning plants dating to MIS 5e, all will be explained.
A mate of mine has a Landrover in Antofagasta – they’re good in the snow. I’m sure he’d rent it out for a beer or two!
It seems a bit odd that despite the post not mentioning climate change that all the responders here went there. It almost seems a bit of a knee-jerk response when all it does is seem to confirm the frequent weather vs climate confusion so often in evidence.
I was there just a few weeks before their last storm hit the Atacama–they had about 3 feet of snow in an area where I saw only a few green plants; the rest of it was just sand, gravel and rock (along with a precious metals mine we were expanding). But even that wasn’t unprecedented–such storms happen every several decades in the Atacama but make little or no impact on the biosphere due to their highly infrequent occurrence.
The other place with a claim to being the driest place on Earth is the Dry Valleys in Antartica that haven’t seen rainfall in 2 million years. Driest doesn’t mean hottest as some posters seem to think.
I am working with a salt company that operates a mine in northern Chile. Normally exporting de-icing salt to exotic places like New York, Baltimore and Boston – now the bad weather comes here right to us. If global warming continues like that, we will sell all-year long! Thank you, Mr. Gore!
In northern Chile a lot of people are affected by the snow/rain & cold, as the houses are not at all made for this.
Is Al Gore around there just now?
That’d explain it.
“The Atacama desert in Chile described as the driest place on Earth just got walloped by an extreme cold front (climate change) and was buried in snow…”
I thought that the interior region of the Antarctic known as The Dry Valleys was the driest place on Earth. They’ve had no rainfall in over two million years!
I Have worked in the Atacama desert several times. It is not uncommon to get rain or snow there. Although not often or to any “schedule” but once a year is not “historic”. It rained for 24 hours while I was there and it was a heavy rain (3 to 5 inches) A government geologist working out of the same camp said he recently witnessed a meter of snow in one day (I think it was the year before).
Did Al Gore recently visit the Atacama desert?
Dear Anthony: A very important post. Hope the more educated Wattsupwiththat regulars will have a say on this phenomenon, which is obviously part of the “interesting times” we are living in.
Now, in a more relaxed manner, we could explain this phenomenon as the consequence of the visit and “lectures” of the Global Warming famous preacher, Al Gore, during last SH summer, to Peru and Chile, when we were warned by his wise words of the dissappearence of all the Andean glaciers, and, consequently, a generalized drought in the Amazon basin and lack of drinking water.
SteveE says:
July 7, 2011 at 5:16 am
Driest doesn’t mean hottest as some posters seem to think.
You are absolutely right: Hottest means Wettest.(a tropical and rainy climate). Your recent record floodings, in the US, were the consequence of more accumulated snow during one of the hardest winter you have had.
well I don’t know about this place
but I did visit a place in the south of Argentina
http://www.letterdash.com/HenryP/ooops-global-cooling-is-coming
The typical Marine West coast regime is far equatorward vs normal in the SH. Same as the NH. On that note, I see some interesting things in the US forecast maps and progs. Presently, there are PoPs for over 80% of the CONUS! 48 hours out there is snow prog’ed for the Northern Rockies, just north of the Canadian border. Out at Monday 11-JUL I see a rather robust West Coast trough prog’ed. Is climatic Fall here already in the NH?
It certainly is dry snow!
Ecotretas
“In order to get moisture into the desert, it must get into the so-called rainshadow. A possible route is from the NNW, which would require a slug of high-precipitable water or moist air to travel poleward along the South American west coast. Currently, a cut-off low or upper-level potential vorticity anomaly is spinning happily off the Chilean coast — and the clockwise flow (cyclonic in the Southern Hemisphere) is distinctly opposite to the typical anti-cyclone situated in that location.”
Another author who would benefit from reading Leroux…
I took the train from La Paz to Arica in 1969. The closer we got to the summit the drier and more desolate became the landscape, but the funny thing was: foot prints were everywhere! As far as I could figure these were the prints of the people who laid the tracks a hundred years before.
In Arica a rare mist blew in from the sea and put the phones and power out of operation. They don’t bother with waterproof insulators there–it NEVER rains. If Bolivia wants to get its coast back all it needs is a few water balloons in its arsenal. –AGF
Is there any better information about this event than this vague NDTV article? Did it snow everywhere in that desert? Did it snow in the driest places and if so, how much?
I’m sure there is a carbon tax somewhere to fix that and provide reparations to the mining towns in the Atacama, and with only a nominal handling fee by the UN.
and here I thought that the dry valleys in Antarctica were the driest places on earth (no recorded moisture in two million years).
Dave Springer says:
July 7, 2011 at 3:08 am
“The Atacama desert in Chile is mistakenly described as the driest place on Earth”
Fixed that for ya! Antarctica contains the driest place on Earth.
That will be due to the Katabatic winds Then.
This event is not inconsistent with natural variability, nor is it inconsistent with the expected acceleration of the hydrological cycle that always accompanies higher levels of CO2. Not enough information to say if this event has been even partially created by the 40% greater amount of CO2 in the atmosphere than was present a few hundred years ago, but this is how the planet has responded to higher CO2 levels for millions of years…lots of CO2 will be removed from the atmosphere by the weathering of the rocks and soils by moisture falling on this desert…not enough to counter the billions of tons that humans are adding each year, but this is one way through negative feedback that CO2 is removed from the atmosphere.
Arica is fed by a perennial stream, so it is clear that the upper elevations get a little rain or snow. You can see on Google Earth. I suspect that the places that got snowed aren’t part of the driest desert. Maybe we can get some recent satellite pictures. –AGF
Checking out Wiki. and its sources, it’s pretty clear that the Atacama has Antarctica beat easily–places where there has been no rain for a hundred thousand years. The nitrates were there to be mined because they never got flushed. GOES satellite picture shows no snow except on the Cordillera, but there’s still too much cloud cover to tell further south: http://www.goes.noaa.gov/FULLDISK/GEVS.JPG