Out in the Pacific Ocean, a powerful storm is forming that will no doubt blow through western Washington tonight, packing a punch of rain, mountain snow and high winds. But while it is almost certain the storm will have an impact on our area, the question is always just how strong it will be.

That question can be hard to answer, especially when it comes to the high winds in our forecast today. The reason is that our area's amazingly varied terrain, from ocean beaches to Puget Sound valleys to the Cascade and Olympic peaks, can focus and funnel winds -- or block them out entirely. Even a small difference in a storm's intensity or path can have a huge impact on the ultimate wind speeds through your neighborhood.

As an example, picture a baseball player throwing a pitch. The throw can appear to be right on target, going straight into the catcher's mitt -- and yet the umpire calls it a "ball" and not a "strike" just because it was an inch or two off of home plate. The same kind of precision plays into whether a day is merely breezy, or takes down big trees. Even a slight difference in the storm's course can take us from a blustery day, to one where the power is out and giant evergreen trees topple.

So far, though, this storm appears headed for our "strike zone," with our computer models taking its center just north of the Olympic Peninsula and then across the north part of Puget Sound. On this track, we are primed for extremely strong and damaging winds later tonight.