Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 329 AM EST Fri Jan 03 2014 Valid 12Z Fri Jan 03 2014 - 12Z Sun Jan 05 2014 ...Heavy snowfall should wind down this morning across the Northeastern U.S... ...Well below normal temperatures will affect the Northeast on Friday... ...The next arctic surge will arrive into the Northern Plains by Saturday... The upcoming period extending into the weekend will continue to feature wintry precipitation and much below normal temperatures. As of early this morning, widespread snow continues to fall across the coastal sections of the Mid-Atlantic and up into New England. Accumulations should continue throughout the morning across coastal sections of New England before winding down as the strengthening surface low exits into the Canadian maritimes. The tightening pressure gradient will significantly enhance the wind field over the northeastern states. The combination of the modified arctic air with the gusty winds will lower wind chill temperatures to the single digits over the Mid-Atlantic while areas of New England can expect readings into the -10s and -20s. Besides the cold, the weather should be rather quiet across this region as a surface/upper ridge builds in the wake. An upper trof diving down into the Pacific Northwest will bring a period of light to moderate precipitation to the region with orographic lift aiding in locally heavier amounts. The progressive nature of this system should clear things out across Washington/Oregon by midday Friday with the activity spreading into the Intermountain West. A lack of moisture should limit snowfall amounts although the higher terrain across western Montana can expect totals nearing a foot through Sunday morning. While one lobe of energy moves across the Central Rockies, the other will slide across the Northern Plains/Upper Midwest. The latter feature will spread an axis of snow across the Upper Midwest and into the Great Lakes with the Upper Peninsula of Michigan expecting 6 to 8 inches of snow based on the latest WPC winter weather forecast. Additional snow will be possible along the associated cold front stretching through the Nation's Heartland and back into the Central Plains. Some of the coldest air of the year should arrive by the weekend over the northern tier of the country. The polar vortex is expected to drop from Central Canada bringing dangerously cold temperatures to the Northern Plains/Upper Midwest by Saturday. Forecast offices over this region suggest lows into the -20s across North Dakota/Minnesota with breezy conditions lowering wind chills to dangerously low levels. Current guidance indicates wind chill temperatures may approach -50F on Saturday night. Elsewhere, scattered showers will persist across South Florida as moisture lingers across lower sections of the Sunshine state. The activity should become a little more organized by Saturday afternoon as a boundary returns northward as a warm front. Rubin-Oster Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php