Let me try to explain..
The first screen on baro mode shows ABSOLUTE pressure. This is the actual air pressure in any location at any given time. It is dependent on the weather and altitude.
The only thing that you can reference (change) in your watch for the barometer is the SEA LEVEL pressure.
Whenever someone looks at the news station, the airport, or the weather channel online, the "Barometric pressure" given is ACTUALLY your SEA LEVEL pressure. (NOBODY gives the absolute pressure because it is different from every 5 feet of each other).
What a barometer does, is it measures the absolute pressure (ie 26.60) and then adjusts it for SEA LEVEL (ie 29.90) so that everyone in that given location is at the same standard. Sea level basically takes out the effect of elevation on your barometer.
So, you are going to look on a website and find your barometric pressure. You adjust it in the "SEA" mode in the barometer mode. There are 3 "DEF" = defaults. This means there is a high, low, and middle default where you cannot actually adjust it beyond or below what your watch actually senses is your barometric pressure (ie you cannot "trick" your watch into thinking you are at an altitude which you are not).
For most accurate results, you want to reference your ALTITUDE, not your barometer. (referencing the barometer will only birng you into a ballpark range of what your altitude is. Referencing your altimeter is actually the most accurate, based off a map).
It is a hard concept to explain through email, you might want to call
Suunto's helpdesk which is available 24 hours.