Analysis of the performance of SisPI to represent the North Atlantic subtropical anticyclone

In this research, the performance of the Short-range Forecast System (SisPI by its acronym in Spanish) to represent the North Atlantic subtropical anticyclone over the parent domain during the 2020 wet season is evaluated. For this, an average of the decade 2010-2019 was calculated using data from the ERA5 reanalysis at different levels of the troposphere for variables geopotential height, relative humidity, temperature and wind, in order to characterize the main systems that disturb the weather in the study area, to obtain the corresponding anomalies and to determine if the errors have more influence of these anomalies or SisPI configuration. For this it was necessary to interpolate SisPI data for make match with the resolution of ERA5 reanalysis and to be able to perform the calculations and generate the maps, for which a Python code was designed. The results suggest that SisPI shows tendencies to locate the high geopotential areas further south of its real position, which produces modifications in the synoptic flow forecasted. On the other hand, the northern and southern borders of the domain have the largest errors, mainly to the north, where, according to the decadal mean and the anomalies obtained in 2020 tends to generate a more baroclinic zone which creates an additional noise over said border. To the south it lies on segments of the ITCZ which may also be the reason for additional sources of errors on the model.