We don't have synonyms for weather gauge yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are weather gage, water gauge and weather-gage.
(n) :
(obsolete, naval) An advantageous position of one sailing vessel with respect to another, because of the direction of the prevailing wind, that allows it to maneuver for an attack etc.
(n) :
(obsolete, naval) An advantageous position of one sailing vessel with respect to another, because of the direction of the prevailing wind, that allows it to maneuver for an attack etc.