Produced by GNUPLOT 4.4 patchlevel 2 980 990 1000 1010 1020 1030 1040 2011 01 2011 07 2012 01 2012 07 2013 01 2013 07 2014 01 2014 07 2015 01 2015 07 2016 01 2016 07 2017 01 2017 07 0 50 100 150 200 250 300 Atmospheric pressure (mbar) Azores-Iceland (mbar) Year Sat Jun 24 09:44:12 2017 Belfast Azores Iceland Azores-Iceland

NAO Reference: http://polarmet.osu.edu/NAO/

METAR files: http://weather.noaa.gov/weather/metar.shtml

Archive of current indices