Using the Multisensor Advected Layered Precipitable Water Product in the Operational Forecast Environment

Abstract

The Cooperative Institute for Research in the Atmosphere, via the Joint Polar Satellite System Proving Ground, developed an advectively blended layered precipitable water (ALPW) product that portrays moisture profiles at a common time across the grid. Using water vapor profile retrievals from the National Oceanic and Atmospheric Administration’s Microwave Integrated Retrieval System (MiRS) aboard polar-orbiting spacecraft, the ALPW product is able to depict the moisture distribution for four atmospheric layers. The ALPW layers are advected forward in time every 3-h using Global Forecast System model winds. Advective blending offers a reduction to the visual limitations seen with traditional non-advected layered precpitable water (LPW) imagery, as satellite swath lines and data discontinuities largely are removed. Having the same temporal resolution as LPW imagery, the new ALPW product offers a more continuous and complete picture of the moisture distribution in these four atmospheric layers (surface–850 hPa, 850–700 hPa, 700–500 hPa, and 500–300 hPa). The advected product also is easier for forecasters to interpret as the analysis at a common time and grid makes the ALPW product comparable to operational model guidance. This paper demonstrates the utility of the ALPW product as a situational awareness tool by highlighting the environments associated with three recent high-impact flash flood events. Initial findings indicate that ALPW data have improved the detection capability for tracking deep tropospheric moisture plumes from source regions well-removed from the flash flood locations. ABSTRACT (Manuscript received 18 December 2017; review completed 11 May 2018)