Yup, this is a problem I still haven't been able to get right. It is in the on INPUT and on TEXT part. For some reason, because of the w| part. If I add a space w |. It doesn't work. But if is just the w|. I t will respond to all W related things.

This is an several bug , into my bot i have a lot of !w.... commands so you must find a way to fix this, try an other way and not the regex.

Also the problem is not only in !weather and on the other commands:

e.g:

!forecastttttttt
!alertsssssssssssssss
!timeeeeeeeeeeee
.....

I am unable to recreate your issue. Other than !forecast. But I will keep an eye on this.

For now, just remove the W from the on text and on input section.

 on $*:INPUT:#: {
  if ($regex($1,/^[!](weather|forecast|forecast5|alert|alerts|alertinfo|alertsinfo|time|current|almanac)/Si)) wunderground $1-
}

on $*:text:/^[!](weather|forecast|forecast5|alert|alerts|alertinfo|alertsinfo|time|current|almanac)/Si:#: {
  wunderground $1-
}

Ok but i don't know why this is happening.

on $*:text:/^!? /Si:#: {
wunderground $1-
} A simple ? after the (weather|forecast|etc|)? /Si: <--will fix the issue.

@rebel9 That works for the onTEXT. But not for the onINPUT

on $*:INPUT:#: {
if ($regex($1,/^!? /Si)) wunderground $1-
}
This doesnt work? If not try almanac)? \w+$/Si))