;  Gets the week number for the hysplit gdas met files
pro get_wnum,sda,wnum
  if sda ge 1 and sda le 7 then wnum=1
  if sda ge 8 and sda le 14 then wnum=2
  if sda ge 15 and sda le 21 then wnum=3
  if sda ge 22 and sda le 28 then wnum=4
  if sda gt 28 then wnum=5
end