Mesoscale convective systems in NW Mexico during the strong ENSO events of 1997-1999

Abstract

Este estudio presenta un análisis de los sistemas convectivos de mesoescala (SCM) de verano que se desarrollaron en el noroeste de México durante los intensos episodios de El Niño Oscilación del Sur ocurridos de 1997 a 1999. Los resultados del análisis de datos geoestacionarios indican que el mayor número de SCM se asociaron con el episodio de El Niño de 1997, y tuvieron un periodo activo más prolongado. Durante el episodio de La Niña de 1999 se observó un menor número de SCM, los cuales se desarrollaron durante un periodo activo menor. La ocurrencia de SCM se vincula con la localización de la cresta y las anomalías anticiclónicas a alturas geopotenciales de 500 hPa y 200 hPa, respectivamente. ABSTRACTThis study presents an analysis of the summertime mesoscale convective systems (MCSs) that developed in northwestern Mexico during the strong ENSO events of [1997][1998][1999]. From the analysis of geostationary data, results indicate that the largest number of MCSs was associated with the 1997 El Niño event throughout a longer active period. During the La Niña event of 1999 fewer MCSs were observed, which had developed over a shorter active period. The occurrence of MCSs is linked to the location of the ridge and the anticyclonic anomalies at 500 hPa and 200 hPa, respectively.

Ocean–atmosphere conditions related to severe and persistent droughts in the Mexican Altiplano

“…Valdes‐Manzanilla () analysed mesoscale convective systems in northwestern Mexico to demonstrate that the highest number of systems recorded was generated during the strong El Niño of 1997–1999. When La Niña conditions occurred in 1999, the number of systems declined and there was less than average rainfall.…”

Wind and Wind Power Ramp Variability over Northern Mexico

“…For the four regions, the increase in ramp events at the beginning of the wet season is associated with MCS. These events are more frequent from June to August over Mexico [48]. The spatial distribution of the systems reported by [49] shows MCS events over the PLATEAU and NEMEX regions, especially frequent from April to August.…”

Thunderstorm and hailstorm environments in Mexico

“…The approximate delimitation of each subregion was based on previous research about climatological characteristics. Six subregions were identified: the Trans‐Mexican Volcanic Belt (FV) with 14 observatories (León‐Cruz et al, 2021), the Yucatan Peninsula (YP) with 6 observatories (Valdés‐Manzanilla, 2022), the Northwest (NW) with 7 observatories (Valdés‐Manzanilla, 2015), the Gulf of Mexico (GM) with 8 observatories (Cavazos, 1999), the Central Highlands (CH) with 10 observatories (Peralta‐Hernández et al, 2008), and the Southwest (SW) with five observatories (Andrade‐Velázquez & Medrano Pérez, 2021). This previous analysis was necessary because no official Mexican database exists on severe weather.…”

“…In this regard, some studies have examined deep convective clouds related to severe weather. For example, mesoscale convective systems (MCS) over northwestern Mexico have been widely analysed during the North American monsoon (NAM) (Farfán et al, 2021; Ramos‐Pérez et al, 2022; Valdés‐Manzanilla, 2015). Likewise, the spatiotemporal distribution of precipitation and deep convective clouds over FV has been analysed, illustrating that both events are related to the orographic features (Brito‐Castillo et al, 2022; León‐Cruz et al, 2021).…”