With regards to air pressure and isobars, if you want to do some basic forecasting as well, then the 500-millibar chart is something that should be examined. Historically (pre-satellite downloading via Iridium and Predict Wind) sailors/mariners would use them to help see what's coming for voyage planning:<p>* <a href="https://www.vos.noaa.gov/MWL/dec_08/milibar_chart.shtml" rel="nofollow">https://www.vos.noaa.gov/MWL/dec_08/milibar_chart.shtml</a><p>* <a href="https://www.oceannavigator.com/basics-of-the-500-millibar-chart/" rel="nofollow">https://www.oceannavigator.com/basics-of-the-500-millibar-ch...</a><p>* <a href="http://familygonesailing.com/2018/01/18/using-500mb-charts-on-forecasting/" rel="nofollow">http://familygonesailing.com/2018/01/18/using-500mb-charts-o...</a><p>* PDF: <a href="https://ocean.weather.gov/articles/mariners_guide_500mb_chart.pdf" rel="nofollow">https://ocean.weather.gov/articles/mariners_guide_500mb_char...</a><p>* <a href="https://www.amazon.com/Weather-Avoidance-Concepts-Applications-Charts/dp/0939837781" rel="nofollow">https://www.amazon.com/Weather-Avoidance-Concepts-Applicatio...</a>
A bit more of detail of all the numbers on Wikipedia <a href="https://en.wikipedia.org/wiki/Station_model" rel="nofollow">https://en.wikipedia.org/wiki/Station_model</a>
This is a good start in understanding what the individual symbols mean - I hope at some point there's a follow-up to how to interpret the higher-level situation to make a forecast.
Be careful of the source of your station report. In the US, station report pressures related to aviation are in units of "inches mercury" ("Hg) with the preceding 2 or 3 omitted. Here is a resource: <a href="https://aviationweather.gov/metar" rel="nofollow">https://aviationweather.gov/metar</a><p>In the grand scheme of weather, it does not make much difference, as the change in pressure in time or location is more important than the units.
That was a fun and interesting read, thanks for sharing.<p>Does anyone know of any EU-region surface weather maps, or are these notations specific to NA based weather maps?