World magnetic model (wmm) 2020 update and black out zone advisory

Original warning text

WORLD MAGNETIC MODEL (WMM) 2020 UPDATE AND
BLACK OUT ZONE ADVISORY.
1. AS PART OF THE REGULAR UPDATE CYCLE OF THE
   WORLD MAGNETIC MODEL (WMM), THE NATIONAL
   OCEANOGRAPHIC & ATMOSPHERIC ADMINISTRATION
   (NOAA), NATIONAL CENTERS FOR ENVIRONMENTAL
   INFORMATION (NCEI), IN COLLABORATION WITH THE
   BRITISH GEOLOGICAL SURVEY (BGS), WILL RELEASE
   THE 2020 WMM ON 10 DEC. THE CURRENT 2015 WMM
   WILL EXPIRE ON 31 DEC.
2. IN ORDER TO AVOID ANY MODEL PERFORMANCE
   DEGRADATION, USERS ARE RECOMMENDED TO DOWNLOAD
   AND INSTALL THE 2020 MODEL COEFFICIENTS, WHICH
   WILL BE PUBLISHED ONLINE AT
   www.ngdc.noaa.gov/geomag/WMM/soft.shtml.
3. THE UPDATED WMM 2020 MODEL WILL INCLUDE NEW
   BLACK OUT ZONES (BOZ), WHICH WILL IMPACT ALL
   NAVIGATION NEAR THE POLES. COMPASS ACCURACY
   IS INCREASINGLY UNRELIABLE APPROACHING THE BOZ,
   WHERE DECLINATION ERRORS OF UP TO 180 DEGREES
   WILL OCCUR.
4. THE WMM IS THE STANDARD MODEL USED BY THE
   U.S. DEPARTMENT OF DEFENSE (DOD), CIVIL AGENCIES,
   THE NORTH ATLANTIC TREATY ORGANIZATION (NATO),
   AND THE INTERNATIONAL HYDROGRAPHIC ORGANIZATION,
   FOR A WIDE-RANGE OF POSITIONING AND NAVIGATION
   SYSTEM APPLICATIONS THAT USE THE GEOMAGNETIC FIELD,
   INCLUDING ALL AIRCRAFT, SHIPS, SUBMARINES AND
   GPS UNITS.
5. FOR FURTHER INFORMATION ON THE BLACK OUT ZONES,
   REFERENCE MIL-PRF-89500B
   www.ngdc.noaa.gov/geomag/WMM/data/MIL-PRF-89500B.pdf.
6. CANCEL THIS MSG 01 JAN 2020.