All-Sky Layered Precipitable Water Products from ABI/AHI and Their Applications in Nowcasting and Forecasting the Severe Storms

Information of moisture distribution and transportation in pre-convection environment is very important for nowcasting and forecasting the severe weather events. The Advanced Baseline Imager (ABI) onboard U.S. GOES-R series and the Advanced Himawari Imager (AHI) onboard Japanese Himawari-8/-9 provide high temporal (30 seconds to 15 minutes) and spatial (2 km) resolution moisture information useful for weather monitoring and forecasting. Algorithms have been developed for all-weather three layered precipitable water (LPW: surface - 0.9, 0.9 – 0.7, and 0.7 – 0.3 in sigma coordinate) retrievals by fusing the ABI/AHI IR band radiances, numerical weather prediction (NWP) model moisture forecasts, and surface temperature and moisture observations. The LPW products from ABI/AHI have been validated with in-situ measurements, generated at the Space Science and Engineering Center of the University of Wisconsin-Madison, and put into the Advanced Weather Interactive Processing System (AWIPS II) in near real-time (NRT) to allow forecasters to monitor a critical ingredient in the initiation, development, and decay of convective cells and systems. These unique LPW products have the advantages of availability in all sky weather conditions, depicting high temporal and spatial features such as dryline. Examples from the NOAA Hazardous Weather Testbed (HWT) taken place 04 May - 12 June 2015, 18 April – 13 May 2016, and 19 June – 21 July 2017 are presented to demonstrate the forecast applications of these very useful products. Another important application is to improve the local severe storm (LSS) forecasts through assimilation of the high temporal and spatial resolution moisture information into regional and storm scale NWP models. Assimilation techniques and approaches have been developed; the impact on heavy precipitation forecasts for LSS from the assimilation of ABI/AHI will be presented.