A trough of low pressure off the Pacific Northwest begins to track inland today, bringing cooler temperatures to the Northwest, although above average temperatures will remain in place over much of the Great Basin, Southern California and the Southwest. Ahead of the trough, an increase in westerly, downslope flow and dry, breezy conditions are likely from the northern Sierra Nevada and western Nevada into much of Oregon and Washington with development of strong downslope flow and gap winds. Areas of the Southwest and southern California will also experience dry, breezy conditions, most notably in southeastern Arizona into western New Mexico, which overlaps with an area of potential for isolated dry thunderstorms in central Arizona. Widespread wetting rain is forecast in the Pacific Northwest, west of the Cascades, and there is a chance of rain and thunderstorms over much of New Mexico, Colorado and the High Plains, extending into the Upper Mississippi Valley. Storms to the east of the Divide are more likely to be accompanied by wetting rain. Southern Florida will continue to receive widespread thunderstorms and areas of heavy rain; up to 2.5 inches in some areas. A dry airmass will begin to flow over Alaska’s eastern interior off the Artic Ocean, potentially producing dry thunderstorms over the northeastern interior. Showers are likely to continue over the southwest and south- central portions of the state.