Assessment of Temperature and Precipitation Forecasts of the WRF Model in the Bahía de Banderas Region (Mexico)

Abstract

The Centro de Ciencias de la Atmósfera at UNAM, in Mexico, uses the Water Research and Forecasting model to provide weather forecasts to the country. In this study, we downloaded the mean temperature and precipitation forecasts of the first 24 h generated by the WRF model in the center of the country. Only the time series of our study region (Bahía de Banderas) was processed from this database, from June to October 2010, and these data were compared with the data recorded in six stations to evaluate the performance of the model at a local level. Data from 12 stations were used to construct the observed temperature and precipitation maps for spatial validation. The results show that the model performance was partially acceptable. The correlation coefficient for hourly temperatures was an average of r=0.84. Errors were less than 2 °C with a BIAS of ±1 °C. For the accumulated 24 h precipitation, however, the results were not satisfactory (r=0.26). The model predicted only 25.7% of the rainy days observed. In terms of spatial distribution, ~2.3 times more rain was observed than had been predicted by the model.