Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 303 PM EST Thu Nov 12 2015 Valid 00Z Fri Nov 13 2015 - 00Z Sun Nov 15 2015 ...Heavy rain possible over the Pacific Northwest and parts of the Northern Rockies... ...Heavy snow possible over the northern most Cascades and Northern Rockies... Heavy precipitation is expected for portions of the Pacific Northwest and the northern Rockies over the next few days. A low pressure system will develop over the Gulf of Alaska and track through the Pacific Northwest and the northern tier of the US as a cold front. Very moist air will stream onshore in conjunction with this system, resulting in a significantly higher 3-day precipitation forecasts for the Northern Rockies, the Olympic and Cascade ranges, along with the surrounding areas. Values of 1 to 4 inches will be common near the base, with higher elevations widely varying from 5 to 12 inches. The highest amounts, which could reach upwards of 17 inches, are likely to occur in the Olympic Mountains. The snow levels will rise as the moisture pushes inland. Snow accumulations will be limited to the northern most Cascades and Northern Rockies through Friday, whereas rain will persist through Saturday evening. A storm system over the Great Lakes will move eastward to the Canadian Maritimes by Friday evening. Rain with embedded thunderstorms will along and ahead of the associated front from the Great Lakes to parts of the Ohio and Tennessee Valleys to the Lower Mississippi Valley will taper off this evening, however the rain will continue over Great Lakes eastward to the Northeast through Friday evening. Additionally, light snow will develop over parts of the Upper Great Lakes. Most of the precipitation will have diminished by Saturday evening for the Northeast. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php