Patagonia Weather Update July 31, 2012

Patagonia Weather Update July 31, 2012

We have just reached the end of a rather snowy July in Patagonia, with ski resorts across the region reporting mid-mountain bases of 70-100 cm (28-40 inches) and snow depths of up to 135 cm (54 inches) in the peaks! Along with the end of this snowy month comes a bit of a lull in the winter weather. There is no need to worry, however, as August and September have been known to be the snowiest months of all, bringing about the famous Santa Rosa storm. We also appear to be in an El Niño year, which typically translates to a wet (snowy) winter in the southern hemisphere. The South American winter certainly came in like a lion this year, and we are hoping to see it continue well into the spring.

NOAA SST Anomaly 30.07.2012 El Niño
The latest Sea Surface Temperature (SST) Anomaly global analysis from NOAA shows above average temperatures in the equatorial Pacific Ocean. Leyman's terms: El Niño is upon us!

Hope alone will not bring us more of what we seek, deep white blankets of the fluffy stuff. We must attempt to understand and look for the ideal conditions in which white gold will fall from the sky, if for no other reason than to give us hope during long periods of high pressure or during a low snow year.

GFS 18 05.08.2012 00 300mb Cutoff Low Pressure System
MeteoStar GFS Model Forecast showing cutoff low pressure system over the central Pacific coast of Chile August 4, 2012.

The current state of things in the atmosphere above the Patagonian region is as follows: a split jet stream flow with a cutoff low pressure system circulating off the central Pacific coast of Chile. This low pressure system will be parked over the area of Northern Patagonia for the next 4-5 days.

Precipitacion Acumulada 3 dias 01.08.2012
3-Day precipitation forecast map from our friend and local meteorologist, Enzo Campetella of, depicting very little precipitation over the next 3 days in the Northern Patagonian region.

We may pick up a few inches of snow from this system, but it doesn’t look like it will be a big producer for us, as it is lacking in strong dynamics. This weather pattern looks to persist until the evening hours of Monday, August 6, at which point the jet stream will once again converge and push further north, bringing along with it more enhanced weather dynamics. It appears as though around this same time frame, we should be seeing a favorable West-Southwest flow carrying large amounts of moisture, accompanied by mid-atmospheric divergence and cold air advection, adding to the atmospheric instability. This system is looking like it will be coming in with strong winds and cold temperatures as the associated cold front crosses the region August 8-9.

Long story short, look for the next major winter storm to hit the Northern Patagonian region toward the end of the first week or early in the second week of August. The cold temperatures should attribute to the kind of low-density powder snow we love, but watch for strong winds (up to 40 knots, 74 km/h, 46 mph) transporting snow and creating dangerous wind slab conditions on the existing snow surface on higher elevation lee faces (East and Northeast). Hint: Be wary of cornices and the loaded slopes beneath them. Be sure to check your local avalanche advisory before venturing beyond ski resort boundaries (fuera de pista).

About Author

<p>Professional Outdoor Guide, specializing in backcountry skiing, heliskiing</p> <p>Stomping grounds: Wasatch Range, Andes Mountains</p>