Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 303 AM EST Fri Dec 19 2014 Valid 12Z Fri Dec 19 2014 - 12Z Sun Dec 21 2014 ***Heavy rain and mountain snow for the Northwest U.S.*** ***Rain and thunderstorms for the Gulf Coast region*** ***Seasonably cool across most of the country through Sunday*** Strong deep-layer flow from the Pacific will keep the weather pattern active from the Pacific Northwest to the central and northern Rockies through Saturday night. A couple of strong disturbances in this fast flow will pivot around a deep low pressure system over the Gulf of Alaska. These disturbances, along with their surface cold fronts, are forecast to bring heavy rain for the coastal areas of the Pacific Northwest, with some amounts in excess of 4 inches possible by Sunday morning. Very heavy snow in the higher mountain ranges could reach 1 to 3 feet with copious moisture being forced up the topography. For the Deep South and Gulf Coast region, a wave of low pressure developing along a frontal boundary over the northern Gulf of Mexico will keep the weather unsettled to close out the work week. Based on the latest forecasts, it appears that the Mid-Atlantic region and the Northeast U.S. should avoid seeing any significant precipitation from this system since it will remain on a more southern track. Elsewhere across the continental U.S., it should be mostly dry with partly cloudy conditions and seasonal temperatures. The exception will be some scattered snow showers near the Great Lakes. The bitterly cold arctic air should remain north of the Canadian border for the next few days. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php