A website may consecutively implement a couple of stylesheets. Why? These are not browser-default stylesheets, the content is definitely styled both times, the first stylesheet is only briefly applied, and, as far as I know, nothing the user does causes the first stylesheet to be replaced by the second, replacement being automatic and maybe script-driven. Weather.com is not the only case (at that site, the effect is visible only on the first loading of the page, not on refreshment, when only the last stylesheet is applied). But why would someone design a page to have two stylesheets in rapid succession? Why not just eliminate the first stylesheet and apply only the second one, as the only stylesheet? I guess there’s an advantage in two, but what?