Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 356 PM EST Sat Nov 14 2015 Valid 00Z Sun Nov 15 2015 - 00Z Tue Nov 17 2015 ***Large storm system to affect the western U.S.*** ***Valley rain and mountain snow expected through Monday*** ***Cool and pleasant conditions for much of the eastern U.S.*** A well-developed low pressure system is forecast to approach the Pacific Northwest coast by Sunday morning ahead of an amplifying upper-level trough. This low is expected to bring widespread precipitation for much of the West Coast and then the Intermountain West. With colder air moving in behind the cold front, snow levels are forecast to lower significantly for the West coast mountain ranges, and then for interior mountains by the end of the weekend. Average rainfall amounts of 1 to 4 inches are likely to occur through Monday across western Washington and Oregon. Noteworthy snow is likely for the higher elevations, with snowfall totals of 8 to 16+ inches forecast in the northern Cascades and Olympics. Strong and gusty winds are also expected to accompany this storm system. For the High Plains and central U.S., southerly winds on the backside of a large surface high over the East Coast will advect increasing amounts of moisture over Texas and northward to Nebraska. Coverage of showers and thunderstorms will increase by Monday, with showers then spreading over the northern Plains and Upper Great Lakes. The same surface high over the eastern U.S. is expected to persist and govern the weather pattern east of the Mississippi River, along with mostly clear skies and moderating temperatures. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php