Suunto TRAVERSE 1.0 User Manual page 70

The weather trend indicator is displayed as a view in the time
display, providing you a quick way to check weather changes.
4.2.
Tue
19:36
21:39
The weather trend indicator is comprised of two lines forming an
arrow. Each line represents a 3-hour period. A change in barometric
pressure greater than 2 hPa (0.59 inHg) over three hours triggers a
change the direction of the arrow. For example:
Storm alarm
A significant drop in barometric pressure typically means a storm is
coming and you should take cover. When the storm alarm is active,
Suunto Traverse sounds an alarm and flashes a storm symbol when
the pressure drops 4 hPa (0.12 inHg) or more during a 3-hour
period.
70
19:36
pressure dropping heavily over the last six hours
pressure was steady, but rising heavily over the last
three hours
pressure was rising heavily, but dropping heavily
over the last three hours
4.2.
Tue