Cooperative Institute for Research in the Atmosphere's
Total Precipitable Water
Product Details
TRANSITIONED PRODUCT DETAILS
Total Precipitable Water
The Total Precipitable Water (TPW) product is dervied from several data sources. These include two composites of Special Sensor Microwave / Imager (SSM/I) passes from the Defense Meteorological Satellites Program (DMSP) (Figure 1A), three composites of the Advanced Microwave Sounding Unit (AMSU) from Polar Operational Environmental Satellites (POES) (Figure 1B), and information from Global Positional Satellite (GPS) meteorlogical data (Figure 1C). GOES Sounder Derived Product Imagery (DPI) will be used to fill in missing land locations over the continental United States. By combining all of these observations, a smooth product is created. This provides information over the continental United States (primarily from GPS data) and over observation poor regions, such as the oceans (from the SSM/I and AMSU data). CIRA's method eliminates the bias between data sets and provides an easier and faster product to analyze.
Figure 1. Component Observations Used in the CIRA Products. (A) Special Sensor Microwave / Imager, (B) Advanced Microwave Sounding Unit, and (C) Global Positioning Satellite meteorological data.
TRANSITIONED PRODUCT DETAILS
Total Precipitable Water Anomaly
The CIRA Total Precipitable Water Anomaly product shows the percentage departure from normal from climatology. The normal value is based on a weekly climatoloty of total precipitable water that comes from NASA's Water Vapor Project (NVAP). The climatology comes from data from 1988-1999, although CIRA plans to expand this time period. The Anomaly assists forecasters to answer the question, "How unusual is this moisture field?" Very high percentage values (200% or more) indicate a strong flooding potential or a possible severe weather indicator, while low values indicate potential fire hazards.
