Evaluation of WRF parameterizations for extreme wind events over the eastern coast of Spain

UTRABO-CARAZA, EDUARDO; ALVAREZ IMAZ, MILAGROS; DILLON, MARIA EUGENIA; GARCÍA SKABAR, YANINA; AGUILAR, ENRIC; AZORIN-MOLINA, CESAR

Conferencia; Annual Meeting of the European Meteorological Society; 2023

Extreme wind speed events cause more than half of the economic losses associated with natural disasters in Europe, and they are becoming more frequent and severe due to climate change. A better understanding of these extreme events is essential to reduce their associated risks. The overall aim of this research is to study the performance of different parametrizations (micro physics and planetary boundary layer) of the WRF model for the simulation of extreme wind speed and gusts events on the eastern coast of the Iberian Peninsula (IP), Spain. Two typical extreme wind events are simulated: (i) a cold front passage in winter (January 4th, 2022), and (ii) a downburst in summer (August 15th, 2021). Three 2-way nested domains are defined, the two largest ones (horizontal resolutions of 9- and 3-km) centered on the IP and the third one (1-km) centered on the Valencian region. The simulations are initialized with data from the ERA5 reanalysis and the boundary conditions in the coarser domain are updated hourly. The evaluation of the simulations is assessed by means of observed data provided by the Spanish State Meteorological Agency (AEMET) including automatic station network data, radar and satellite images and atmospheric soundings. The model accurately simulates the passage of the cold front, matching the time and magnitude of the observed wind speed and gusts. However, the WRF model does not reproduce the downburst, at least at the observed location. In general, the simulations are more sensitive to the choice of the boundary layer parameterization than to the microphysics parameterization.