So it’s add forward speed to dirty side only?I didn’t know that.
Add the forward speed to the side of the storm with winds also moving the same direction. A storm with 100mph winds is moving 15mph N, add forward speed to the winds on the E side of the eyewall, as these winds are also moving N. This isn’t always on the dirty side. But it is confusing.
If you think about it the hurricane is spinning Counter clockwise. So on the left side I would say that you would subtract forward speed from the total. Add it instead for the Right side. No change if either in front or behind the eye. Don’t know if that is totally correct, but it is what makes sense.