LSA-NW EAOP-00 MBRFC WSR-88D Stage III Hourly Precipitation Imagery
                            

     1.0  General Description
     

          The Missouri Basin River Forecast Center (MBRFC)  Stage III
     Hourly Precipitation composite product is one of several imagery data
     sets provided in the GEWEX Continental-Scale International Project (GCIP)
     Large Scale Area - North West (LSA-NW) Enhanced Annual Observing Period 
     1900 (EAOP-00). The MBRFC imagery covers a sector (approx. 36 to 51 
     degrees N latitude by 90 to 115 degrees W longitude box) over the 
     Missouri River Basin. The MBRFC imagery contains hourly composites of 
     radar derived precipitation for the LSA-NW EAOP-00 time period 
     (1 April 2000 through 31 March 2001).
     

     2.0  Detailed Data Description
     

          The MBRFC routinely ingests WSR-88D precipitation derived
     products (Level III) from each of the radar sites with coverage in the
     Missouri River Basin domain.  In addition, the MBRFC ingests real-time 
     precipitation data from hundreds of gauges.  These data are used to 
     support real-time operations (i.e., hydrological modeling) as well as the 
     production of various radar "Stage Products" used by the River Forecast 
     Center.  
     
          The MBRFC produces a number of derived or "Stage" products
     using all the available radars and precipitation gage data in the Missouri
     River Basin.  A Stage II product is produced by merging radar precipitation 
     estimates (Stage I) with ground truth data provided by the precipitation 
     gages.  The Stage II estimates are then composited into a Stage III 
     precipitation 4 x 4 km resolution area averaged mosaic for the Missouri 
     River Basin.  Hourly Stage III total precipitation estimates were then 
     produced and saved as Graphical Interchange Format (GIF) imagery by the 
     MBRFC.  
     
          These GIF images can be viewed using any standard GIF display
     software package. However, any additional detailed information from the
     original files (i.e., pixel digital values, navigation, etc.) are not 
     retrievable from the GIF image, but can be obtained from the actual 
     data available from the University Corporation for Atmospheric 
     Research/Joint Office for Science Support (UCAR/JOSS). 
     
          The WSR-88D radars have difficulty detecting precipitation when
     the rain drops are very small or when the precipitation is in the form of
     snow.  Under these conditions precipitation estimates tend to be under
     estimated.  Large Hail within a storm causes the radar to over estimate
     precipitation amounts.
     
     2.1  Detailed Format Description
     
          General information on GIF files, structure and format are provided
     in the References.
     
     2.2  Data Remarks
     
           The GIF Imagery were produced directly from the screens of
     workstations at the MBRFC.  As part of producing the imagery, the
     scroll bars and some program buttons from the workstation screen
     were "captured" in the GIF imagery.  The user must be aware that
     any scroll bars or program buttons are NOT functional and executing
     any of the  control-type key sequences indicated by these buttons and
     bars might produce unwanted results depending on the type of GIF
     viewer used. 
     
     
     3.0  Quality Control Processing
     

          No additional quality control or re-navigation was performed on the
     imagery by the UCAR/JOSS.
     

     4.0  References
     

     Kay: Graphics File Formats, 2/E.  ISBN: 0-07-034025-0, McGraw Hill.
     
     Luse, M: Bitmapped Graphics Programming in C++. ISBN: 0-201-
          63209-8, Addison-Wesley.