A weak cold front exits the region Saturday morning leaving partly cloudy skies and westerly winds behind in its wake. The polar night jet should be positioned somewhat south of El Calafate with 175 kt winds at the 10 mb level, but a small shift in the position could make a big difference for flying. As of now updrafts look only modest on Saturday, at best, but that could change if the position of the westerlies shifts northward. Sunday is a mixed bag, winds aloft improve and there will presumably be better updrafts, but clouds may make flying conditons marginal, with overcast below FL100. Monday is pre-frontal and may be better, but wind direction will be crucial, and right now it’s looking too northerly.
Front and associated low dissipates off the west coast over the next couple of days. While the surface front weakens the associated upper low and trough moves north of El Calafate Monday, turning the upper winds to a southerly direction. As the weak trough and upper low past generally north of the area on Monday and Tuesday, models are forecasting generally westerly upper level winds, however the direction will be determined by the exact path of the trough passage, and small deviations to the path could result in large swings in upper winds at El Calafate. Upper winds become briefly westerly again mid-day Wednesday with the passage of a dirty ridge over the area. Another stronger frontal system develops and comes onshore Friday, bringing rain to El Calafate in the Friday-Saturday time frame.
Another weak front moves in late Wednesday, bringing lowering clouds and east winds at the surface. A few rain showers Wednesday afternoon possibly turning to snow flurries during the night night. Clearing and winds turning westerly Thursday afternoon, with a possible flying opportunity. Still another storm brings rain or snow late Friday into Saturday.
A deep 946 mb low passes south of South America on Tuesday. A cold front trailing behind it weakens as it interacts with the Andes and remains almost stationary. Wednesday brings another, weaker cold front to the west coast, bringing northerly winds ahead of it. Another cold front moves in overnight Wednesday and early Thursday, bringing light snow to El Calafate. Clearing and winds turning westerly Thursday afternoon. Still another storm brings rain or snow late Friday.
Over this past weekend of the August 19, 2017, the Airbus Perlan Mission II made another flight while in El Calafate, Argentina. Despite the small window of flying time due to the icy conditions, the Perlan 2 pressurized its cabin to soar above 21,500+ feet”. Below are some photos from the hangar in El Calafate prior to August 19, flight. Photo Credits: The Perlan Project