Environment associated to deep convection under SALLJ conditions: a case study.

PALOMA BORQUE; PAOLA SALIO; MATILDE NICOLINI; YANINA GARCIA SKABAR

WEATHER AND FORECASTING

AMER METEOROLOGICAL SOC

Lugar: Boston; Año: 2010 vol. 25 p. 970 - 984

0882-8156

The present work focuses on the study of the environmental conditions preceding the development of a group of subtropical mesoscale convective systems over central and northern Argentina on 6 – 7 February 2003, this situation took place during the South American Low Level Jet Experiment (SALLJEX). This period was characterized by an extreme northerly low-level flow along the eastern Andes foothills (South American Low Level Jet - SALLJ) event. The entire studied episode was dominated by the presence of a very unstable air mass over northern Argentina and a frontal zone near 40 ºS. The SALLJ generated an important destabilization of the atmosphere due to the strong humidity and differential temperature advection. Orography provided an extra lifting motion to the configuration of the regional wind field, efficient in forcing the initiation of convection. Once convection developed it moved and regenerated in regions where convective instability was horizontally homogeneous and stronger.– 7 February 2003, this situation took place during the South American Low Level Jet Experiment (SALLJEX). This period was characterized by an extreme northerly low-level flow along the eastern Andes foothills (South American Low Level Jet - SALLJ) event. The entire studied episode was dominated by the presence of a very unstable air mass over northern Argentina and a frontal zone near 40 ºS. The SALLJ generated an important destabilization of the atmosphere due to the strong humidity and differential temperature advection. Orography provided an extra lifting motion to the configuration of the regional wind field, efficient in forcing the initiation of convection. Once convection developed it moved and regenerated in regions where convective instability was horizontally homogeneous and stronger.