“…The main objective of the paper by Oikonomou et al (2018) is to evaluate the tropospheric delay performance for Global Navigation Satellite Systems (GNSS) integrated water vapor estimation by using GPT2w model, ECMWF's IFS (European Centre for Medium-Range Weather Forecasts) reanalysis model and ground meteorological data from two stations of the permanent network of Cyprus and Greece. The period from 27 May to 3 June 2018 is characterized by two different synoptic conditions: high pressure with fair weather in central Mediterranean (Greece), on the one hand, and high instability over the upper levels of the atmosphere that resulted in thunderstorms inland and mountainous areas during midday over the Eastern Mediterranean (Cyprus), on the other hand.…”