i looked this up, and found this information on where/how to catch Kyogre and Groudon in Emerald:

Anytime after each one is released, you can go to the second floor of the
Weather Institute on Route 118 where the scientist will tell you about
either severe sun or severe rain in a certain place.

The routes are randomly chosen from:
-Route 105
-Route 125
-Route 127
-Route 129

and are on an undetermined time limit. Once you are told where the severe
weather is, immediately go to that Route and search for the cave.

In sunlight, Groudon's Cave is somewhere on land.
In rain, Kyogre's Cave is somewhere underwater, so Dive is needed.

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Is this information correct? i talked to the scientist on the second floor of the weather station, but he said nothing about it. This is after i released Groudon and Kyogre, called Rayquaza down to calm them, and caught Rayquaza. i haven't yet beaten the Elite Four and Champion. Can i catch them at this point in Emerald? If so, how do i activate the Weather Institute event? If the info i looked up isn't correct, where and how do i catch Kyogre and Groudon in Emerald?

Fix this first.

Thanks, Goji! By the way, your avatar is rather cool.

Thank you. It was made by an old friend of mine of a character I created.