Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 255 PM EST Tue Nov 03 2015 Valid 00Z Wed Nov 04 2015 - 00Z Fri Nov 06 2015 ...Heavy snow possible across the higher elevations of the Intermountain West... ...Flash flooding possible on Thursday for portions of the southern plains/Mississippi valley... ...Above average temperatures expected to continue for much of the central and eastern U.S... A vigorous low pressure system will move across the western U.S. tonight into Wednesday, before emerging into the High Plains late Wednesday afternoon. The surface low pressure system along with a vigorous upper-level trough will result in widespread precipitation tonight and Wednesday from the Four Corners region north to Montana and portions of Idaho. While rain will fall in the valleys/lower elevations, the atmosphere will be cold enough to support snow for much of the elevated terrain of the west, with 3 to 6 inches of snow possible for many areas. The heaviest snow is expected to fall across the Colorado Rockies, where up to 20 inches of snow will be possible at the highest elevations. Additionally, the relatively energetic nature of the storm system will promote strong, gusty winds across much of the west, with 30 to 40 mph winds expected, and gusts forecast to exceed 50 mph in some areas. By Wednesday night into Thursday, the frontal system will move into the plains. While snow showers will linger across the central Rockies into Thursday, the focus will shift to the central U.S., where moisture streaming northward from the Gulf of Mexico ahead of the system will result in numerous showers and thunderstorms. Moisture and instability will be sufficient for heavy rainfall -- and the threat of flash flooding will exist for portions of the southern plains and Mississippi valley on Thursday. Additionally, the Storm Prediction Center is forecasting a slight risk of severe thunderstorms for portions of the southern plains on Thursday. Additional snow will be possible across the northern Intermountain West on Thursday as a relatively fast-moving upper-level disturbance dives into the northwestern U.S. from British Columbia. Meanwhile, high pressure at the mid and upper-levels of the atmosphere will promote generally dry conditions with above average temperatures on Wednesday across most of the central and eastern U.S. High temperatures on Wednesday will be 10 to 20 degrees above average from the central/northern plains eastward to the Northeast. The one exception to the dry conditions in the east will be the coastal southeastern U.S. where a weakening frontal boundary will linger, keeping scattered showers in the picture through Wednesday. Ryan Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php