Question: Does Storm Alert work while an activity?

Hi to all!

i have a generell question. as i understood:
Storm-Alert comes in, when the air pressure goes down to a specified value. (default, 4 hPa).
When starting an activity, GPS is only used, for calibration the barometric altimeter at Start. then the watch uses only the barometric value, for elevation. and all changes in air pressure are changing the elevation.
Since there is no continuous recalibration with GPS. how will the watch know, if i am running or hiking up an hill, or the weather changes?

thx for infos!

Mario