PGM > FUNC > GLOB > WX Check Int: and WX 1050Hz Th:.
FUNC > GLOB gets you into the really advanced settings. WX Check Int is default at 60, which means it checks once every 6 seconds. You can probably bump it up to around 85-90 (8.5-9 seconds). The All Hazards tone should be around 10 seconds, but it's never guaranteed that all WX stations will follow that to the dot. WX 1050Hz Th sets how long it sits on the frequency to listen for the tone, the minimum is 10 (1 second).