Latest developments in NWC SAF/High Resolution Winds product

Abstract

The “High Resolution Winds product (HRW)”, developed inside the “Satellite Application Facility on support to Nowcasting and very short range forecasting (NWC SAF)” software package, provides a detailed calculation of Atmospheric Motion Vectors locally and in near real time. Several important changes have been implemented in its algorithm in the last two years, up to current HRW v2012 version. The AMVs extraction capabilities have been extended, tuned and validated for seven SEVIRI channels (HRVIS, VIS06, VIS08, WV062, WV073, IR108, IR120), considering both Cloudy AMVs and Clear air Water Vapour AMVs. “CCC method” proposed by Borde and Oyama (2008) has been implemented in the algorithm for the AMV height assignment, using NWC SAF/Cloud Top Temperature and Height product data. The results of the last version validation, showing significant improvements through smaller RMSVDs, are shown in this paper. Preliminary results of a study that aims to better understand the temporal and spatial scaling issues associated to the AMV extraction are also shown. In the framework of this study, HRW v2012 AMVs have been extracted from MSG-1 Rapid scan HRVIS and VIS08 channel data. Results are studied for different target sizes (8x8 to 40x40 pixels) and temporal gaps between images (5 to 90 minutes). The outputs have been validated against Radiosounding winds and NWP analysis wind fields.