CIRA Experimental Layered Precipitable Water for 18 UTC 3 January 2017 Sfc-850 500-300 700-500 850-700 “Atmospheric Rivers (ARs)” of moisture or what we called in the 1990’s “Moisture Plumes” mm http://cat.cira.colostate.edu/sport/layered/advected/lpw.htm Univ of WI/CIMSS MIMIC TPW ver2 18 UTC 3 Jan 2017 NOAA/NESDIS % of Normal TPW 18 UTC 3 Jan 2017 The term "atmospheric river" was first coined ~15 years ago. But those who were looking at polar orbiting microwave satellite data/sensors in the 1990's, like myself, from the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave Imager, have used a similar term "moisture plume” or concentration of highest moisture to speak of these now more well known "Atmospheric Rivers" of moisture. You can follow the progress of these "atmospheric rivers" of moisture from NOAA/NESDIS for the upcoming western US event at: http://www.ospo.noaa.gov/Products/bTPW/TPW_Animation.html?product=EAST_PACIFIC_TPW and a complementary product called the Percent of Normal TPW at: http://www.ospo.noaa.gov/Products/bTPW/TPW_Animation.html?product=EAST_PACIFIC_PCT . Another very good Total Precipitable Water product is the University of WI/ CIMSS MIMIC TPW ver 2.0 at: http://tropic.ssec.wisc.edu/real-time/mtpw2/product.php?color_type=tpw_nrl_colors&prod=epac×pan=24hrs&anim=html5 . And don't forget that "atmospheric rivers" of moisture can be found at many different levels of the atmosphere, so find time to follow them at CIRA/Colorado State University's Experimental Advected Layered Precipitable Water Product at: http://cat.cira.colostate.edu/sport/layered/advected/lpw.htm . Sheldon Kusselson, Retired NOAA/NESDIS