FIGURE T28. Vertically integrated water vapor or precipitable water (top) and anomaly (bottom), as determined by the SSMI (Ferraro et. al, 1996: Bull. Amer. Meteor. Soc., 77, 891-905). In bottom panel, regions with above- (below) normal water vapor are indicated by dark (light) shading. Units are kg (m)^-2. Anomalies are calculated from the 1987–2006 base period means.