The radar data is tabular. To import it into a raster format, I took one
of the hourly tables (64 cols and 43 rows), and appended the following header
to the text file (starting on the first line):

NCOLS 64
NROWS 43
XLLCORNER 45240010    (given in the associating text file)
YLLCORNER 45260000    (given in the associating text file)
CELLSIZE 2000         (cells are 2 km x 2 km)

I deleted all other text and hourly data from the file leaving just the 
above header and the radar data. 

I then accessed ARC/INFO and submitted the followint command:

asciigrid 94_05_00_txt 94_05_00 FLOAT

-where 94_05_00_txt is the appended text file and 94_05_00 is the outputted
 grid. 

For mapping purposes, I then determined the largest data value (by doing
a describe command), divided 255 by the largest value (i.e 256/122.34) and
multiplied the entire grid by that amount to shift the values from 0 to 255
-ex.   describe 94_05_00
       (ouptuts results telling max value = 122.34)

       256/122.34 = 2.09

       grid
       94_05_00map = 94_05_00 * 2.09

94_05_00map is now the reclassed grid of the radar data with shifted values. 

To make the map, I went into ArcView, selected New View:
  selected View->AddTheme
  (select 94_05_00map)

You will get a black and white map. To change colors...
 select Theme->EditLegend
 select Colormap...
 
I manually chose colors for some range of values 0-80 = yellow, 81-100 = green, etc....

To produce the legend, I selected
  View->Layout
and manually created the legend

To produce the final jpeg file, I executed xv, chose grab and selected the 
map. I saved as jpg option.