It is not because we want to scream at you! This practice goes back many, many years and relates to international requirements for message dissemination. Some of our international partners still use low-tech dissemination technology which requires the continued use of ALL CAPS. Since the U.S. is an international member of the World Meteorological Organization (WMO), we follow those guidelines that still exist for the benefit of all nations. That is why TAFs, AIREPs, Marine Forecasts, etc. are typed in ALL CAPS.
However, they are considering changing it. But that change is coming mighty slowly.
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