A multisensor, blended, layered water vapor product for weather analysis and forecasting

Abstract

This paper describes the creation of a near real-time, near-global, four-layer (surface–850, 850–700, 700– 500, and 500–300 hPa) blended layered water vapor (LWV) product using retrieved soundings from five polar-orbiting satellites [National Oceanic and Atmospheric Administration (NOAA)-18 and NOAA-19 satellites; Defense Meteorological Satellite Program F-18 satellite; Meteorological Operational satellite program’s Metop-A satellite; and National Atmospheric and Space Administration (NASA) Aqua satellite]. Both layer precipitable water (LPW) and layer relative humidity (LRH) are included in the blended LWV product. The NASA Atmospheric Infrared Sounder Version 6 retrieval product and NOAA Microwave Integrated Retrieval System soundings are used to create the product, and the use of retrieved water vapor profiles from multiple satellite inputs at different local times allows visualization of the flow of water vapor in layers. The product has advantages and complements geostationary water vapor imagery, derived products from geostationary satellites, and radiosondes in tracking moisture over data sparse regions in cloudy conditions. LPW profiles show absolute values at each layer of the column, while LRH profiles give a sense of whether the column is moistening or drying with height. Examples of the product are given for a severe weather case, the September 2013 Colorado Front Range floods, and a landfalling tropical depression. The usefulness of the product is discussed from the perspective of how tools commonly used by forecasters to analyze water vapor are augmented by the blended layered water vapor fields.