Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 233 AM EST Mon Dec 07 2015 Valid 12Z Mon Dec 07 2015 - 12Z Wed Dec 09 2015 ...Heavy rain over the Pacific Northwest... ...Heavy snow possible over the Northern Cascades... ...Heavy rain possible over the lower/moderate elevations of the Northern Intermountain Region/Rockies... ...Snow possible over the highest elevations of the Northern Intermountain Region/Rockies... Multiple upper-level strong impulses will move into the Pacific Northwest along with multiple plumes of moisture through Tuesday. Onshore flow off the Pacific will aid in producing rain over the Pacific Northwest with lighter amounts over adjacent portions of Northern California through Tuesday evening. Farther inland, rain and higher elevation snow will develop over parts of the Northern Intermountain Region/Rockies through late Monday night. On early Tuesday morning the snow levels will rise over the region producing rain at the lower and moderate elevations with snow at the highest elevations through Tuesday evening. One of the upper-level impulses will be strong enough to develop a front over parts of Upper Midwest on Tuesday afternoon into evening. The system will produce rain over portions of the Northern Plains into parts of the Upper/Middle Mississippi Valley on Tuesday. Meanwhile, a dissipating front over the Ohio Valley and a developing front along the Southern Mid-Atlantic/Southeast Coast will aid in developing rain over parts of the area on Monday, ending on Tuesday morning. Elsewhere, a lingering front near the southern tip of Florida will aid in producing light rain over Southern Florida through Tuesday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php