@Article{RibeiroSelu:2019:ClQuCo,
author = "Ribeiro, Bruno Zanetti and Seluchi, Marcelo Enrique",
affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Centro
Nacional de Monitoramento e Alertas de Desastres Naturais
(CEMADEN)}",
title = "A climatology of quasi-linear convective systems and associated
synoptic-scale environments in southern Brazil",
journal = "International Journal of Climatology",
year = "2019",
volume = "39",
number = "2",
pages = "857--877",
month = "Feb.",
keywords = "quasi-linear convective systems, severe thunderstorms, southern
Brazil, synopticclimatology.",
abstract = "This study presents a 9-year climatology and composite analysis of
quasi-linearconvective systems (QLCSs) in southern Brazil (SB).
QLCSs are identified usingradar imagery and defined as a 100-km
long, 40-dBZ convective line that lasts forat least 1 hr. QLCS
cases associated with at least three severe wind reports are
clas-sified as severe. Composites of the synoptic-scale
environments and severe convec-tive weather parameters are
constructed for severe and non-severe cases of threesynoptic
patterns found as the most recurrent in QLCS cases. QLCSs are more
fre-quent and more likely to be severe during spring, while very
few cases occur dur-ing winter. Most cases occur during late night
and morning, corroborating previousresearch of mesoscale
convective systems in this area, but the percentages of
severecases are higher in late afternoon and early night. Faster
QLCSs, particularly thosewith velocities greater than 50 km/hr,
have higher probability of being severe incomparison to slower
systems. The three synoptic patterns more often related toQLCS
occurrence in SB are characterized by a mid-level trough upstream
of SB(type 1), a mid-level trough west of the Andes (type 2) and
predominance of zonalflow over SB (type 3). In general, there is a
low-pressure system over northwesternArgentina extending a trough
to SB, where low-level moisture flux convergenceand warm advection
occur. In severe cases, the sea-level pressure is lower in
north-western Argentina and there is greater low-level
northwesterly flow over SB. Thetype 1 is the most frequent pattern
when QLCSs are observed in SB and is also thetype with higher
percentage of severe cases. Convective available potential
energy(CAPE) and downdraft CAPE are good discriminators between
severe and non-severe cases in type 1 and 2 environments, while
the 1,000500-hPa bulk wind dif-ference is a better predictor in
type 3 cases.",
doi = "10.1002/joc.5847",
url = "http://dx.doi.org/10.1002/joc.5847",
issn = "0899-8418",
label = "self-archiving-INPE-MCTIC-GOV-BR",
language = "en",
targetfile = "ribeiro-climatology.pdf",
urlaccessdate = "29 mar. 2024"
}