Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 325 PM EST Thu Jan 08 2015 Valid 00Z Fri Jan 09 2015 - 00Z Sun Jan 11 2015 ...Well below normal temperatures will continue generally east of the Rockies... ...Heavy lake effect snows are expected during the next couple of days... ...Potential icing may occur along the Texas/Mexico border into Central Texas... A very cold pattern will remain in place as a deep upper trough anchors itself across the northeastern sector of the continent. Several disturbances are forecast to surge from the Upper Midwest into the Great Lakes and northeastern U.S. supplying multiple reinforcements of the arctic air mass. High temperatures on Friday are expected to range from 20 to 30 degrees Fahrenheit below normal across a vast majority of the central U.S. and into the Upper Great Lakes. This places high temperatures at or below freezing as far south as Central Texas. All of this arctic air will work its way eastward bringing more sub-freezing readings to the eastern third of the country. Of course the accompanied wind will draw the wind chill temperatures to very low readings at times. This overall pattern is expected to persist well into the weekend while the western states remain more mild in nature. The anomalously cold air overriding the milder lake surfaces will invigorate multiple periods of lake effect snow showers. Vertical temperature profiles appear quite unstable given such cold air funneling overhead. Favorable wind trajectories will allow significant snows to fall downwind of many of the major lakes, particularly east of Lakes Erie and Ontario. Over the course of the next couple of days, the WPC winter weather desk expects 12 to 18 inches of snow east of this pair of lakes while 6 to 10 inches will be more commonplace downwind of Lakes Superior and Huron. A slow moving upper low will gradually work its way across Mexico during the period. Moisture return from the western Gulf of Mexico will pick up in advance of this system allowing for a more concentrated axis of precipitation. Areas affected should include Central/Eastern Mexico and into the southern half of Texas. Enough cold air lingering at the lowest levels of the atmosphere may allow for a mixed phase event. A mixture of freezing and sleet is possible along much of the Rio Grande and extending inland to sections of Central Texas. While light in nature, any ice accumulations will make travel hazardous in this sector of the country. Rubin-Oster Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php