Severe Hailstorms near the Southern Andes Range in the Presence of Mountain Waves

A. DE LA TORRE; HIERRO, R.; LLAMEDO, P.; A. ROLLA; ALEXANDER, P.

ATMOSPHERIC RESEARCH

ELSEVIER SCIENCE INC

Lugar: Amsterdam; Año: 2011 vol. 101 p. 112 - 123

0169-8095

Experimental satellite and radar data and numerical simulations at constant pressure levelswere analyzed to estimate the relative importance of mountain waves during the developmentof 3 severe deep convection events with abundant hail precipitation in Mendoza, Argentina.The mesoscale numerical simulation model WRF 3.0 was used to determine the regionalcirculation previous to the deep convection. GPS radio occultation data were used to validatethe simulations. It was found that updrafts generated by mountain waves constitute a possibletriggering mechanism during the storms initiation. A continuous wavelet transform analysiswas applied to the vertical velocity. In all cases, large amplitude stationary waves wereobserved just before the initiation of convection, possibly triggering it. The horizontal directionof propagation and the corresponding horizontal and vertical wavelengths of both main modeswere identified. Vertical velocity and convective inhibition index were found to be potentialstorm forecasting flags in this region.