Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 258 PM EST Thu Dec 29 2016 Valid 00Z Fri Dec 30 2016 - 00Z Sun Jan 01 2017 ...Heavy snowfall to continue into Friday for interior New England and downwind of the lower Great Lakes... ...Heavy to excessive rainfall possible across the Lower Mississippi Valley on Saturday... ...Afternoon high temps could be 10 to 20 degrees above normal on Friday across the Plains... A surface low just off the Mid-Atlantic coast today will rapidly deepen as it moves up the Northeast coastline and eventually curves back into eastern Canada by Friday morning. Heavy snowfall across interior New England is expected to continue tonight and into Friday, with storm total accumulations of 1 to 2 feet, or more, possible. In addition to the heavy snowfall, gusty winds will also accompany the storm making travel across the area hazardous. On the backside of the system, cold air and favorable flow across the Great Lakes will produce lake enhanced snowfall, with the heaviest accumulations expected downwind of lakes Erie and Ontario, where lake effect snow warnings are in effect. Accumulating snow is also expected along favorable upslope regions of the central Appalachians. A cold front just off the Pacific Northwest coast will push inland this afternoon and move across the Northwest on Friday. Rain and mountain snow will spread across the Intermountain West with heavy snowfall possible in the higher elevations of the Washington Cascades, northern Idaho, and western Montana. Conditions ahead of the boundary across the Plains on Friday will be warm, with afternoon high temperatures expected to be 10 to 20 degrees above normal. As the surface low associated with this system tracks from the northern Plains to the Great Lakes, light accumulating snowfall may be possible from far northern North Dakota to the lower Great Lakes Friday and Saturday. South of here, southerly flow ahead of the cold front will tap into Gulf of Mexico moisture increasing the chance for organized rainfall across the Lower Mississippi Valley on Saturday. Heavy to excessive rainfall could be a threat across southeast Texas and Louisiana to the north of a warm front lifting through the western Gulf. Across the Southwest and Four Corners regions, rain and mountain snow will also be possible Friday into Saturday as shortwave energy moves through. A second system dropping into the Pacific Northwest on Saturday brings another round of rain and snow to the region, with snow even possible in the lower elevations later in the day as there should be very cold air behind the front. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php