IWV MEASUREMENT AND MODELLING WITH GNSS AND NWP (WRF) OVER NORTHWEST BULGARIA

In recent decades, the increase in the number and intensity of high-impact weather events, like intense precipitation, hail and thunderstorms has been an indisputable trend worldwide. In Bulgaria they are common in the summer months and cause large economic losses. As a part of the project "Balkan-Mediterranean real-time severe weather service", since February 2020, the Sofia University Global Navigation Satellite System (GNSS) Analysis Center processes in operational near-real time mode (NRT) stations in Bulgaria. In this study the Integrated Water Vapour (IWV) for four stations in Northwest Bulgaria was calculated using the Weather Research and Forecasting (WRF) model and the results are compared with IWV derived from the GNSS-Meteorology concept. The results obtained lead to the conclusion that the model IWV is higher than the one derived from GNSS.