Study of Severe Weather in South America (credit: Nature)

DISCUSSION: The United States may be the tornado capital of the world, but severe weather (e.g., severe thunderstorms, hail, etc.) occurs frequently in other parts of the world like the east side of the Andes in Argentina.  In particular, thunderstorms there in Argentina tend to mirror storms in the United States that produce tornadoes, but the ones in Argentina tend to not produce tornadoes.  However, they can cause extensive flooding and hail damage and be prolific lightning producers.  A picture of such a storm over farmland is shown above.

There are a lot of unknowns concerning these storms in South America, including why they don't tend to produce tornadoes, despite possessing many of the characteristics believed favorable for such circulations.  To improve our understanding of these South American storms and to reduce the fatalities and damage they cause, two related field campaigns are currently being conducted from 1 November through mid-December.  The first campaign is called the Remote sensing of Electrification, Lightning, and Mesoscale/microscale Processes with Adaptive Ground Observations (RELAMPAGO) which includes a collection of mobile weather instrumentation brought in from the United States.  This is the largest such field program conducted outside the United States.  The focus of the second project is related to how aerosols (small particles in the atmosphere) influence the development of convective storms.  It is possible, for example, that more particles in the atmosphere may make it harder for clouds to produce rain, rainout, and dissipate, allowing storms to persist longer and grow bigger and stronger.  This second project is called the Cloud, Aerosol, and Complex Terrain Interactions (CACTI) project.  Funding for both of these projects is being provided from United States (e.g., National Science Foundation), Argentina, and Brazil national research agencies.

Many such field programs have been conducted in the United States to improve our understanding of storms there.  These have resulted in better watches/warnings and better protection of lives and property.  The aim of these two field programs in South America is similar (i.e., mitigation of storm losses).  Some specific goals of these projects is to give people better warnings about flash flooding or give them more lead time to prepare their crops for an impeding hail storm.  For more information about these field campaigns, please click here.

To learn more about other atmospheric phenomenon across Central and South America, be sure to click here!

©2018 Meteorologist Dr. Ken Leppert II