Precipitable Water Vapor Forecasting

ForO (Forecasting the Observatories)


WRF 3.8

Introduction

 

At IAC we have validated the Weather Research and Forecasting (WRF) model for precipitable water vapour (PWV) forecasting as a fully operational tool for optimizing astronomical infrared (IR) observations at Roque de los Muchachos (ORM) and Teide Observatory (OT). For the model validation we used GNSS-based (Global Navigation Satellite System) data from the PWV monitor located at the ORM. Excellent agreement was found between the model forecasts and observations, with R = 0.951 and R = 0.904 for the 24 and 48-h forecast time series respectively. The 48-h forecast was further improved by correcting a time lag of 2 h found in the predictions. The final errors, taking into account all the uncertainties involved, are 1.75 mm for the 24-h forecasts and 1.99 mm for 48 h. We found linear trends in both the correlation and RMSE of the residuals (measurements - forecasts) as a function of the forecast range within the horizons analysed (up to 48 h). Assuming a linear trend, the extrapolated forecast error up to 72 h is 2.4 mm. In summary, the WRF performance is excellent and accurate, thus allowing it to be implemented as an operational tool at ORM and OT (from Pérez-Jordán et al, 2018).

The concept of ForO
Web Interface
ForO Operational Architecture
WRF Public Domain Notice
References