Consists of precipitable water analyses (in centimeters to thousandths) on the whole mesh octagon grid. Analyses available only for the Northern Hemisphere north of about 20 degrees N latitude for the hours 00Z and 12Z. Data sources include conventional surface reports and upper-air observations. Layers included in the analyses are: Surface to 850 MB, 850 to 700 MB, 700 to 500 MB, 500 to 400 MB, 400 to 300 MB, 300 to 100 MB. Available from High Resolution Analysis for period after 1988. Element reported is: Precipitable Water.