Storm systems are centered around an area of low atmospheric pressure and the lower the pressure the more potent the storm. Here in the Northern Hemisphere, winds circle counterclockwise around the central low, sweeping waves and precipitation in that direction.
Currently, a strong "Nor'easter" is centered off the mid-Atlantic Coast. Having pummeled inland areas with high winds and heavy snow, it is now raking the coast of New England; as the strong winds come ashore, high waves and storm surge cause coastal flooding and beach erosion. Meanwhile, in the Pacific Northwest, another strong storm has brought high winds and heavy precipitation to Northern California, the Cascades and the Sierra Nevada; since the storm is centered off Oregon, the coastal effects are greatest to its south as the counterclockwise winds lash the shore.
Of course, both storms are gradually moving off to the east, the Nor'easter into the North Atlantic (where it may affect the Canadian Maritimes) and the Pacific storm across the Great Basin, the Rockies and the Northern Plains. While the Colorado mountains should get some snow, the Front Range urban corridor will likely be spared (though we need the precipitation).
