E. Tuduri et C. Ramis, THE ENVIRONMENTS OF SIGNIFICANT CONVECTIVE EVENTS IN THE WESTERN MEDITERRANEAN, Weather and forecasting, 12(2), 1997, pp. 294-306
The environmental characteristics associated with 313 significant conv
ective events in the western Mediterranean are investigated using radi
osonde ascents made in Mallorca (Spain). The events are separated into
five groups, based on the observed event (hail, heavy rain, ''dry'' s
torms, storms with heavy rain, and tornadoes). Classic stability indic
es, as well as values of convective available potential energy and hel
icity, are considered for each group. These traditional convective ind
ices appear not to provide good guidance for discriminating environmen
ts associated with each group of events. In order to classify the envi
ronments, each sounding is defined by means of 34 variables that descr
ibe the thermal and humidity vertical structure, instability, precipit
able water, and helicity. A cluster analysis shows that four different
vertical structures appear, Each kind of event shows preference for t
he environments defined by a cluster. A simple method is presented for
sounding classification using the four categories obtained from the c
luster analysis, The method looks for the best correlation between a p
articular sounding and those defined by each cluster.