Re: PROBLEM WITH PLOTTED STATION MODEL DATA

From: Fred Clare (fred@XXXXXX)
Date: Mon Nov 16 1998 - 12:06:15 MST


> I've got another problem with the Station Model Data. I use the
> following commands
> CALL MAPTRN(18.,113.,XO,YO)
>
> IMDAT(1,3) = '11472'
> IMDAT(2,3) = '43269'
> IMDAT(3,3) = '10120'
> IMDAT(4,3) = '20100'
> IMDAT(5,3) = '30000'
> IMDAT(6,3) = '40480'
> IMDAT(7,3) = '51025'
> IMDAT(8,3) = '61250'
> IMDAT(9,3) = '79650'
> IMDAT(10,3) = '83692'
>
>
> CALL WMSTNM(XO,YO,IMDAT(1,3))
>
> However there is something wrong with the data on the output symbol.
> For example the air temperature appears as '54' instead of '10' and the
> dew point is '50' instead of '10'.
>
> It was not mentioned in the user guide whether to use degree celsius for
> the temperature or not, however according to WMO the temperatures and
> dew points are expressed in term of degree celsius in the synop data.
> Also the precipitation appear as '492', which I cannot understand why!
>
> Thank you for your assistance!!
  
  In the U.S., the current surface air temperature and dew point are
  plotted in whole degrees Fahrenheit (see, for example, "Meteorology
  Today" by C. Donald Ahrens). In Wmap, the temperatures are coded as
  degrees Celsius in tenths of a degree. This exmplains why your coded
  temperature of 12.0 degrees C is plotted as 54 degrees F., and your
  coded dew point of 10 degrees C is plotted as 50 degrees F.

  Wmap codes precipitation in millimeters for 0 to 989 and plots the
  value in hundreths of an inch with no decimal. Precipitation values
  from 990 to 999 are reserved for higher resolution for minimal
  precipitation. The value 990 will result in the letter T (for
  "Trace") being plotted. For values in the interval 991 to 999,
  subtract 990 and the result is the precipitation in micrometers.
  Thus, your coded precipitation of 125 millimeters is plotted as
  4.92 inches (without the decimal).

  Fred



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